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2026-08-09cifs: add fscache_resize_cookie() to cifs_setsize()Frank Sorenson1-0/+1
commit fa724e235cfdb0fb0bb427d0f9dfe864ae27403e upstream. Several code paths update the VFS inode size by calling netfs_resize_file() and cifs_setsize(), but omit the corresponding fscache_resize_cookie() call, leaving the fscache cookie out of sync with the actual file size: - cifs_file_set_size() in inode.c: server-side truncation via setattr - cifs_do_truncate() in file.c: truncates to zero on O_TRUNC open - smb2_duplicate_extents() in smb2ops.c: file clone extending EOF - smb3_simple_falloc() in smb2ops.c: two branches that extend EOF via write-range and SMB2_set_eof respectively Since every caller of cifs_setsize() must resize the fscache cookie, add the call to cifs_setsize() itself, consistent with how truncate_pagecache() is already consolidated there. Fixes: 70431bfd825d ("cifs: Support fscache indexing rewrite") Fixes: 93a43155127f ("cifs: Fix missing set of remote_i_size") Fixes: 110fee6b9bb5 ("smb: client: fix missing timestamp updates with O_TRUNC") Fixes: 7a06d3b816d7 ("smb/client: emulate small EOF-extending mode 0 fallocate ranges") Cc: stable@vger.kernel.org Cc: David Howells <dhowells@redhat.com> Cc: Paulo Alcantara <pc@manguebit.org> Cc: Huiwen He <hehuiwen@kylinos.cn> Signed-off-by: Frank Sorenson <sorenson@redhat.com> Reviewed-by: Paulo Alcantara <pc@manguebit.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-09binfmt_misc: don't leak the user namespace when the mount failsChristian Brauner1-17/+15
commit b8206f516fe7cbe785cf44bf09c17c438d7c3cad upstream. bm_get_tree() takes a reference to the user namespace and hands it to get_tree_keyed() as the sget key. sget_fc() moves that reference into sb->s_fs_info and clears fc->s_fs_info, so from that point on the superblock owns it and bm_free() doesn't see it anymore. The superblock drops it in ->put_super(). But generic_shutdown_super() only calls ->put_super() from inside the if (sb->s_root) branch, so nothing releases it when bm_fill_super() fails: - The kzalloc_obj() failure leaves s_root NULL and the whole branch is skipped. - A simple_fill_super() failure in the file loop leaves s_root set, but s_op still points at simple_super_operations, which has no ->put_super(). bm_fill_super() installs s_ops only once simple_fill_super() returned success, and installing it earlier wouldn't help either because simple_fill_super() overwrites s_op. Either way vfs_get_super() calls deactivate_locked_super() and the reference is gone for good. binfmt_misc mounts are available in a user namespace and both the inode and the dentry cache are SLAB_ACCOUNT, so an unprivileged caller under a tight memory cgroup can fail simple_fill_super() on demand and leak one user namespace per attempt. Drop the reference in ->kill_sb() instead, which runs unconditionally, the same way nfsd and rpc_pipefs release their keyed s_fs_info. That also stops ->put_super() from clearing s_fs_info while the superblock is still on @fs_supers. generic_shutdown_super() leaves it there on purpose so that sget_fc() keeps finding it until kill_sb() has run, but a NULL s_fs_info makes test_keyed_super() miss it, so a concurrent mount for the same user namespace skips the grab_super() wait and creates a second superblock for a namespace that is still being torn down. Link: https://patch.msgid.link/20260728-work-binfmt_misc-usernsleak-v1-1-dbd8d5e626e7@kernel.org Fixes: 21ca59b365c0 ("binfmt_misc: enable sandboxed mounts") Cc: stable@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-09binfmt_misc: don't let an 'F' entry pin its own instanceChristian Brauner1-0/+4
commit 79055d82772b9584f259b747fe40ff56a076678d upstream. An entry registered with 'F' opens its interpreter at registration time and holds that file until the entry is freed. Any entry nobody removes by hand only gets closed once the binfmt_misc superblock is shut down. If the interpreter lives on a mount that keeps that superblock alive the two pin each other: binfmt_misc sb -> inode -> entry -> interp_file -> vfsmount -> binfmt_misc sb TL;DR the file is never closed. Once the mount namespace is gone there is nothing left to unregister through either. There are two ways to trigger this bug: - Point the interpreter at the instance itself. Its files are regular files owned by the mounter and both bm_get_inode() and simple_fill_super() leave i_op at empty_iops. So notify_change() falls back to simple_setattr() and chmod +x works. We never set SB_I_NOEXEC and so open_exec() accepts it. - Use the instance as an overlayfs lower layer. The overlay superblock holds a clone_private_mount() of every layer until it is destroyed and that clone is in no namespace. So umount_tree() never reaches it. That's a DoS. And it isn't only the superblock that leaks. It pins the user namespace it was mounted in, so every iteration permanently eats one of the caller's user namespace charges. So let's just do the sane thing. SB_I_NOEXEC makes open_exec() fail on the instance's own files and s_stack_depth makes overlayfs reject the layer before it ever takes a clone. That also covers the ecryptfs and fuse passthrough variants. What 'F' promises is unchanged. The stable tag is narrower than the Fixes tags on purpose. Before sandboxed mounts this needed global root against the single instance everyone shares, and the change doesn't apply to those trees anyway. Note that SB_I_NODEV is implicitly raised for userns mounts but raise it explicitly here as well. Link: https://patch.msgid.link/20260728-work-binfmt_misc-selfpin-v1-1-74df5daeca5b@kernel.org Fixes: 948b701a607f ("binfmt_misc: add persistent opened binary handler for containers") Fixes: 21ca59b365c0 ("binfmt_misc: enable sandboxed mounts") Cc: stable@vger.kernel.org # v6.7+ Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-09binfmt_misc: reject a flag character as the field delimiterChristian Brauner1-0/+4
commit 8e85d50ba1117fd446bf9a250bd8a97d48384bdc upstream. The registration string starts with a user chosen delimiter that separates the individual fields. So that the field parsers terminate even on a truncated string create_entry() pads the buffer with that same delimiter: memset(buf + count, del, 8); Most fields are scanned for the delimiter with strchr()/scanarg() and happily stop on the padding. The flags field is different: instead of scanning for the delimiter check_special_flags() consumes the flag characters 'P', 'O', 'C' and 'F' and stops at the first byte that is none of them, relying on the trailing delimiter to end the scan. If the delimiter is itself a flag character the padding no longer acts as a terminator. The scan swallows all eight padding bytes and keeps reading past the end of the allocation until it hits a byte that is not a flag character. For example registering PaPEPPxPPiP with 'P' as the delimiter (name "a", type extension, magic "x", interpreter "i", empty flags) leaves the flag scan running off the end of the buffer. The registration is rejected in the end because the parser does not stop exactly at buf + count, but only after the out of bounds read has already happened. With an unlucky allocation layout the scan can walk into an unmapped page; under KASAN it is reported as a slab out of bounds read. binfmt_misc mounts are available to unprivileged users in a user namespace so the read is reachable without privileges. Reject a delimiter that is one of the flag characters up front. Such a registration was always rejected anyway, only after the out of bounds read, so no valid registration string changes meaning. Link: https://patch.msgid.link/20260710-work-binfmt_misc-locking-v3-3-a162f7cb58d6@kernel.org Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-09binfmt_misc: use exe_file_deny_write_access() for the interpreter cloneChristian Brauner1-2/+8
commit fa5990ca8fd917003e526036bcc50413edb9722c upstream. For MISC_FMT_OPEN_FILE entries load_misc_binary() clones the registered interpreter file and denies write access to the clone via plain deny_write_access(). The clone is installed as bprm->interpreter and later released by the exec machinery through exe_file_allow_write_access() which skips the i_writecount increment for files with FMODE_FSNOTIFY_HSM set. The deny and allow side can therefore come to different conclusions when pre-content watches are in play: if a pre-content watch is added to the interpreter after registration every subsequent exec through that entry takes a write denial on the clone that is never paired with a write allowance, driving the interpreter inode's i_writecount further down with each exec and leaving the interpreter unwritable even after the entry and all its users are gone. Take the write denial via exe_file_deny_write_access() so both sides of the pairing base their decision on the same file mode, and propagate failure instead of silently ignoring it: an interpreter that is concurrently open for writing now fails the exec with ETXTBSY, exactly like an interpreter freshly opened via open_exec() would. Link: https://patch.msgid.link/20260710-work-binfmt_misc-locking-v3-2-a162f7cb58d6@kernel.org Fixes: 0357ef03c94e ("fs: don't block write during exec on pre-content watched files") Cc: stable@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-09binfmt_misc: restore write access when removing an entryChristian Brauner1-1/+3
commit db1856ea9196cf6e015d12199a34c0b9313c7bfa upstream. Registering an entry with the MISC_FMT_OPEN_FILE flag opens the interpreter via open_exec() which denies write access to it for as long as the entry exists. Removing the entry closes the interpreter file via filp_close() but never restores write access, leaving the inode's i_writecount permanently negative. Opening the interpreter for writing keeps failing with ETXTBSY long after the entry is gone until the inode is evicted from the inode cache. Commit 90f601b497d7 ("binfmt_misc: restore write access before closing files opened by open_exec()") fixed the same imbalance in the error path of bm_register_write() but the actual removal path has been leaking the write denial since the introduction of the flag. Restore write access in put_binfmt_handler() before closing the interpreter file. Link: https://patch.msgid.link/20260710-work-binfmt_misc-locking-v3-1-a162f7cb58d6@kernel.org Fixes: 948b701a607f ("binfmt_misc: add persistent opened binary handler for containers") Cc: stable@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-09ksmbd: reject repeated SMB2 NEGOTIATE requestsNamjae Jeon3-15/+37
commit cb469993b3a61a72653770856d37af616d72d05f upstream. Unauthenticated client can send multiple successful SMB2 NEGOTIATE requests on one connection before SESSION_SETUP. While the connection is in KSMBD_SESS_NEED_SETUP, smb2_handle_negotiate() accepts another SMB3.1.1 NEGOTIATE and overwrites conn->preauth_info with a new allocation. Only the final allocation is freed when the connection is released, leaking one object for every additional successful request. A repeated SMB2 NEGOTIATE after a dialect has been selected is a protocol violation. MS-SMB2 section 3.3.5.4 requires the server to disconnect without replying in this case. Set the connection exiting when rejecting the request, in addition to suppressing the response. Reject SMB2 NEGOTIATE unless the connection is new or is waiting for the SMB2 NEGOTIATE that follows an SMB1 multi-protocol negotiate. Serialize both SMB1 and SMB2 negotiation paths under conn->srv_mutex, since they update connection-wide dialect and negotiation state. Move the locking contract to ksmbd_smb_negotiate_common(), where the state and dialect are selected, and add ksmbd_conn_new() for consistent state access. Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org Reported-by: Runa Takemoto <takemotoruna223@gmail.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-09afs: Fix UAF when sending a messageDavid Howells1-1/+2
commit 4af1ec68d54b3871155914d584fb10669c41a861 upstream. In afs_make_call(), there's a race with async call reception and destruction. If a call is dispatched that doesn't have call->write_iter set (used to specify the data content for FS.StoreData), then the first rxrpc_kernel_send_data() will not set MSG_MORE in the msghdr. Once rxrpc_send_data() queues the last request packet, the response could come in at any time and cause the call to be completed and put. However, afs_make_call() will look at the call again to see it ->write_iter should be handled - something it's only allowed to do if it has its own ref on the call. Whilst this is the case for synchronous calls, it isn't true for async calls such as FS.FetchData. There's also a potential UAF in afs_make_call() in the event that an asynchronous call is being sent, but the call fails in some way (e.g. it gets aborted from the server). The problem there is that afs_make_call() tries to abort a call if the rxrpc send fails, but the asynchronous notification from rxrpc may have caused the afs_call to be torn down. generic/650 plays games with randomly taking CPUs offline, and can interject a significant delay such that the call is deallocated before afs_make_call() gets to check call->write_iter - and a UAF ensues (caught by KASAN). BUG: KASAN: slab-use-after-free in afs_make_call+0x1c90/0x2210 [kafs] Read of size 8 at addr ffff888035e050e8 by task fsstress/1409 Fix this by making afs_make_op_call() give the op->call its own ref rather than transferring the caller's ref to it and then dropping the ref when afs_make_call() returns. This also means that the afs_make_call() func never loses its ref on the call now. Fixes: eddf51f2bb2c ("afs: Make {Y,}FS.FetchData an asynchronous operation") Fixes: e49c7b2f6de7 ("afs: Build an abstraction around an "operation" concept") Link: https://sashiko.dev/#/patchset/20260702144919.172295-1-dhowells%40redhat.com Reported-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260723113452.566619-4-dhowells@redhat.com cc: Jeffrey Altman <jaltman@auristor.com> cc: linux-afs@lists.infradead.org cc: stable@kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-09afs: Fix afs_fs_fetch_data() to subtract transferred from lenDavid Howells1-1/+1
commit 222052c6be186f2074b3a4d741d5de200f654c43 upstream. Fix afs_fs_fetch_data() to subtract subreq->transferred from subreq->len rather than adding it. Fixes: f28fc2010d62 ("afs: Eliminate afs_read") Link: https://sashiko.dev/#/patchset/20260713081022.2186481-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260723113452.566619-3-dhowells@redhat.com cc: Marc Dionne <marc.dionne@auristor.com> cc: Jeffrey Altman <jaltman@auristor.com> cc: linux-afs@lists.infradead.org cc: stable@kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-09afs: Fix afs_fs_fetch_data() to set call->asyncDavid Howells1-0/+3
commit d568a43f6dbba3ba006304d95fd09862bd482a2f upstream. Fix afs_fs_fetch_data() to set call->async on an async operation as does afs_fs_fetch_data64(). Fixes: eddf51f2bb2c ("afs: Make {Y,}FS.FetchData an asynchronous operation") Link: https://sashiko.dev/#/patchset/20260702144919.172295-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260723113452.566619-2-dhowells@redhat.com cc: Marc Dionne <marc.dionne@auristor.com> cc: Jeffrey Altman <jaltman@auristor.com> cc: linux-afs@lists.infradead.org cc: stable@kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-09fs/proc/task_mmu: fix PAGEMAP_SCAN written state for PMD holesKiryl Shutsemau (Meta)1-2/+18
commit 40de8160ca7f67d14619ee0351ce5d68fc4a237a upstream. PAGEMAP_SCAN reports an unpopulated PTE in a uffd-wp VMA as written, but a range with no page table at all -- a PMD hole -- is skipped: pagemap_scan_pte_hole() tests p->cur_vma_category, which never carries PAGE_IS_WRITTEN, so the hole is neither reported nor (under PM_SCAN_WP_MATCHING) armed. In a uffd-wp VMA, WP_UNPOPULATED installs uffd-wp markers when protecting a range, allocating page tables as needed, so an unpopulated slot is treated as written -- see the pte_none() handling in pagemap_page_category(). A missing marker therefore means the range was zapped, e.g. via MADV_DONTNEED. This applies to anon and shmem VMAs. An anonymous THP is write-protected in place as a huge PMD, so a full-PMD MADV_DONTNEED clears it to pmd_none -- a hole with no page table -- and pagemap_scan_pte_hole() misses it. For a MAP_PRIVATE|MAP_ANON mapping MADV_DONTNEED has fill-with-zeros semantics, so a write-tracking checkpoint/migration tool (e.g. CRIU) treats the range as unchanged and keeps its previous contents; after restore or live migration the process reads stale data instead of zeroes -- data corruption. Report a hole in a non-hugetlb uffd-wp VMA as written, matching the pte_none handling in pagemap_page_category(); the existing PM_SCAN_WP_MATCHING path then arms it via uffd_wp_range(). hugetlb is excluded: pagemap_hugetlb_category() reports an empty hugetlb entry (huge_pte_none) as not-written, unlike pagemap_page_category(), which reports pte_none as written. pagemap_scan_pte_hole() fires for a hugetlb slot only when it has no page table; keeping that not-written matches how an allocated-but-empty hugetlb entry reads, so the hole and the empty-entry cases agree within the VMA. Link: https://lore.kernel.org/20260715144234.442721-2-kirill@shutemov.name Fixes: 2bad466cc9d9 ("mm/uffd: UFFD_FEATURE_WP_UNPOPULATED") Signed-off-by: Kiryl Shutsemau <kas@kernel.org> Reported-by: Sashiko AI review <sashiko-bot@kernel.org> Closes: https://sashiko.dev/#/patchset/20260707151349.92143-1-kirill@shutemov.name Tested-by: Muhammad Usama Anjum <usama.anjum@arm.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Peter Xu <peterx@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Zenghui Yu <zenghui.yu@linux.dev> Assisted-by: Claude:claude-fable-5 Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-09fs/proc/task_mmu: fix PAGEMAP_SCAN written state for unpopulated ptesKiryl Shutsemau (Meta)1-2/+12
commit 07b4377bdbe74a3ec0c8da5849d014f70e003384 upstream. PAGEMAP_SCAN reports an unpopulated pte differently depending on which path serves the request. The PAGE_IS_WRITTEN fast path in pagemap_scan_pmd_entry() reports a pte_none as written (and, under PM_SCAN_WP_MATCHING, arms a marker); pagemap_page_category() returns 0 for the same pte_none. A request that cannot take the fast path (an extra category bit, category_anyof_mask or category_inverted) therefore reports the pte as clean and skips arming it. A range that was populated and then MADV_DONTNEED'd reads as written via one mask and clean via another, and in the latter case is not re-armed for the next round -- an incremental-dump consumer (e.g. CRIU) using a richer mask drops the zapped range and stops tracking writes to it. Report pte_none as written in pagemap_page_category() too. A pte_none carries no uffd-wp marker, i.e. it is not write-protected -- the same condition under which the present and swap cases already report PAGE_IS_WRITTEN. The fast path applies no VMA test, so neither does this. The hugetlb and fully-unpopulated-PMD (no page table) scans have no PAGE_IS_WRITTEN fast path, so they do not exhibit the per-entry divergence and are left unchanged. Add a pagemap_ioctl selftest that populates a range, drops it with MADV_DONTNEED, and checks that the fast path and the generic (category_anyof_mask) path both report every page written. Link: https://lore.kernel.org/20260707151349.92143-1-kirill@shutemov.name Fixes: 12f6b01a0bcb ("fs/proc/task_mmu: add fast paths to get/clear PAGE_IS_WRITTEN flag") Signed-off-by: Kiryl Shutsemau <kas@kernel.org> Cc: Muhammad Usama Anjum <usama.anjum@collabora.com> Cc: David Hildenbrand <david@kernel.org> Cc: Jann Horn <jannh@google.com> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Assisted-by: Claude:claude-fable-5 Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-09ocfs2: fix boundary check in ocfs2_check_dir_entry() to use buffer offsetJoseph Qi1-2/+3
commit df8ce7ab48d01ac4f247599b35f0506d95ff57e1 upstream. Commit 390ac56cf0f6 ("ocfs2: add boundary check to ocfs2_check_dir_entry()") added an out-of-bounds guard using the caller-supplied 'offset' argument: if (offset > size - OCFS2_DIR_REC_LEN(1)) return 0; However, 'offset' and 'size' are not measured against the same base for all callers. In the block-based lookup path, ocfs2_find_entry_el() passes 'offset' as an absolute offset into the whole directory: i = ocfs2_search_dirblock(bh, dir, name, namelen, block << sb->s_blocksize_bits, bh->b_data, sb->s_blocksize, res_dir); while 'size' is a single block size (sb->s_blocksize). For any directory entry located in the second or later block, 'offset' is >= sb->s_blocksize, so the guard rejects every such entry even though it is perfectly valid and lies entirely within its block buffer. This makes mounting fail for filesystems whose system directory spans more than one block, e.g. a volume formatted with a small block size: mkfs.ocfs2 -b 512 -C 4096 -N 2 -T datafiles --fs-features=usrquota,grpquota ocfs2_check_dir_entry:314 ERROR: directory entry (#18: offset=512) too close to end or out-of-bounds ocfs2_init_local_system_inodes:496 ERROR: status=-22, sysfile=12, slot=0 ocfs2_mount_volume:1757 ERROR: status = -22 The dirent's position within the buffer being validated is ((char *)de - buf), which is what the rest of the function already uses (via next_offset) and what must be bounds-checked against 'size'. Compute that buffer-relative offset and use it for the guard. The subtraction is reordered to size - buf_offset < OCFS2_DIR_REC_LEN(1) to avoid an unsigned underflow when size is smaller than the minimal record length. Link: https://lore.kernel.org/20260710040512.3310736-1-joseph.qi@linux.alibaba.com Fixes: 390ac56cf0f6 ("ocfs2: add boundary check to ocfs2_check_dir_entry()") Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com> Reviewed-by: Dmitry Antipov <dmantipov@yandex.ru> Tested-by: Dmitry Antipov <dmantipov@yandex.ru> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Jun Piao <piaojun@huawei.com> Cc: Heming Zhao <heming.zhao@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-09btrfs: zoned: fix missing chunk metadata reservationGuanghui Yang1-15/+19
commit 8bc4d7209611e8aa9d5409b6a4a86a9eb91b69a3 upstream. reserve_chunk_space() stores the return value of btrfs_zoned_activate_one_bg() in ret. The helper can return 1 after successfully activating a block group, but ret is later used to decide whether to reserve metadata for chunk tree updates. As a result, successful activation skips btrfs_block_rsv_add() and leaves trans->chunk_bytes_reserved unchanged. Use a separate variable for the activation result so positive success does not affect the later reservation. Keep activation failures in ret instead of returning early so the function uses the common tail path. Fixes: b6a98021e401 ("btrfs: zoned: activate necessary block group") CC: stable@vger.kernel.org Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Guanghui Yang <3497809730@qq.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-09erofs: cap LZMA stream pool sizeMichael Bommarito2-1/+16
commit c9b47e6b23114e939b17f818471c7a46e59006e7 upstream. fs/erofs/decompressor_lzma.c sizes the module-global MicroLZMA stream pool from num_possible_cpus() when the lzma_streams module parameter is unset, then z_erofs_load_lzma_config() preallocates one image-supplied dictionary per stream, accepting dictionaries up to 8 MiB. On high-CPU systems, a small EROFS image can pin hundreds of MiB of vmalloc-backed decoder state until the erofs module is unloaded. Impact: An EROFS image mounted by the system can pin up to 8 MiB of vmalloc memory per LZMA stream, either as intended or unexpectedly. Bound the default stream count by a new CONFIG_EROFS_FS_ZIP_LZMA_DEFAULT_MAX_STREAMS option, default 16, so the worst-case default preallocation is 128 MiB if the number of CPUs is no less than 16 while preserving the existing per-image dictionary limit. An explicit lzma_streams module parameter is still honoured as-is, so administrators who deliberately size the pool are not affected. Fixes: 622ceaddb764 ("erofs: lzma compression support") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com> Reviewed-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-09btrfs: raid56: fix scrub read assembly submitting no readsMykola Lysenko1-6/+5
commit c4c0673e4cb15b0c127e6d00732a2427bdd12c11 upstream. Commit 5387bd958180 ("btrfs: raid56: remove sector_ptr structure") converted the bio-list membership checks from sector pointers to physical addresses. The two conversions in rmw_assemble_write_bios() kept their polarity (skip the sector when it is NOT in the bio list, i.e. when there is nothing to write), but scrub_assemble_read_bios() has the opposite polarity -- skip the sector when it IS in the bio list, because then there is nothing to read -- and the conversion flipped it: - sector = sector_in_rbio(rbio, stripe, sectornr, 1); - if (sector) + paddr = sector_paddr_in_rbio(rbio, stripe, sectornr, 1); + if (paddr == INVALID_PADDR) continue; Since a parity-scrub rbio's bio list only holds the empty completion bio, the result is that scrub_assemble_read_bios() submits no reads at all. finish_parity_scrub() then compares the parity it computes from the (cached, correct) data stripes against whatever happens to be in the freshly allocated, uninitialized stripe pages: - if the garbage differs from the computed parity, the sector is "repaired" and written back -- accidentally producing the correct on-disk result; - if a recycled page happens to still hold the old (correct) parity content, the sector is deemed clean, dropped from dbitmap, and the actually-corrupt on-disk parity is left in place. (Scrub reports no errors either way: there is no counter for P/Q corruption by design, so the bug here is purely the failure to read and repair.) The second case is intermittent because it depends on page-allocator recycling. Observed with fstests btrfs/297 (raid5, 2 devices): the corrupted P stripe intermittently stays corrupt after a scrub -- roughly 1/10 runs on x86-64 KVM and up to 7/8 on a UML build whose timing favors page reuse. Since the bio-list check can never be true for a parity-scrub rbio -- raid56_parity_alloc_scrub_rbio() adds a single empty completion bio (asserting bi_size == 0), bio_paddrs[] is only populated by index_rbio_pages() which is never called for BTRFS_RBIO_PARITY_SCRUB, and rbio_can_merge() refuses to merge rbios of different operations -- remove the dead check entirely and assert the invariant instead, as suggested by Qu Wenruo. After this fix the injected corruption is read, detected and repaired in every run (8/8 UML, 10/10 KVM), and the new assertion never fires across the full fstests raid group. Fixes: 5387bd958180 ("btrfs: raid56: remove sector_ptr structure") CC: stable@vger.kernel.org # 7.1+ Suggested-by: Qu Wenruo <quwenruo.btrfs@gmx.com> Assisted-by: Claude:claude-fable-5 Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Mykola Lysenko <nickolay.lysenko@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-09iomap: add a separate bio_set for iomap_split_ioendChristoph Hellwig1-2/+19
[ Upstream commit c679ce3be6cb63763d68ab9b5d9d73ddc0a40762 ] iomap_split_ioend can split bios that already come from iomap_ioend_bioset and thus deadlock when the bioset is exhausted. Add a separate bio_set to avoid this deadlock. Christian Brauner <brauner@kernel.org> says: Mark iomap_ioend_split_bioset static as it is only used in ioend.c, fixing the sparse warning reported by the kernel test robot. Fixes: 5fcbd555d483 ("iomap: split bios to zone append limits in the submission handlers") Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://patch.msgid.link/20260629125229.3400726-1-hch@lst.de Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-09ksmbd: use memcmp() to compare ClientGUIDsNamjae Jeon1-2/+2
[ Upstream commit e8bb506e6ef749ac0336f3e579d8d02396b7d832 ] ClientGUID is a fixed-size binary value and can contain embedded NUL bytes. strncmp() stops comparing at the first NUL byte, so different ClientGUID values can incorrectly be treated as equal. Use memcmp() in SMB3 multichannel session binding and FSCTL_VALIDATE_NEGOTIATE_INFO to compare all SMB2_CLIENT_GUID_SIZE bytes. Fixes: f5a544e3bab7 ("ksmbd: add support for SMB3 multichannel") Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Reported-by: Samu <nomomentomori@gmail.com> Suggested-by: Samu <nomomentomori@gmail.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-09ksmbd: fix use-after-free in __close_file_table_ids()Namjae Jeon1-0/+2
[ Upstream commit e7188199eff46a636f3436356f0aae039be6dd66 ] A ksmbd_file can remain alive after logical close while another session holds a temporary reference obtained through ksmbd_lookup_fd_inode(). ksmbd_close_fd() currently marks the file closed and drops the idr-owned reference, but leaves the pointer published in the closing session's idr until the final reference is dropped. If the foreign holder performs the final ksmbd_fd_put(), __put_fd_final() supplies the foreign session's file table to __ksmbd_close_fd(). The object is then freed without being removed from its owner's idr, and the owner session later dereferences the stale pointer during file-table teardown. Remove the volatile id from the owner's idr while ksmbd_close_fd() still holds that table's lock, and clear volatile_id before dropping the idr-owned reference. A later foreign final put then only performs physical destruction and cannot remove the object from the wrong table. Fixes: 8510a043d334 ("ksmbd: increment reference count of parent fp") Reported-by: Yunseong Kim <yunseong.kim@est.tech> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-09ksmbd: return success for deferred final closeNamjae Jeon1-1/+3
[ Upstream commit c5db4de8988f1a621556ca5c4537f77b766ca07d ] ksmbd_close_fd() marks an open file as FP_CLOSED and drops the file table reference. If another in-flight request still holds a reference, the final close is deferred until that request drops its reference. The function currently returns -EINVAL in that deferred-final-close case because fp is cleared when the reference count does not reach zero. That turns a valid close into STATUS_FILE_CLOSED. smb2.compound_find.compound_find_close sends QUERY_DIRECTORY and then closes the same directory handle before receiving the find response. The query holds a reference while it builds the response, so close must mark the handle closed and return success even though final teardown is delayed. Track whether the handle was successfully transitioned to FP_CLOSED and return success when only the final close is deferred. Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Stable-dep-of: e7188199eff4 ("ksmbd: fix use-after-free in __close_file_table_ids()") Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-09netfs: Fix folio_queue ENOMEM in writeback by adding a mempoolDavid Howells7-31/+47
[ Upstream commit 1d78d56c43ef3768183e8370e7367b162700e049 ] Fix the handling of folio_queue allocation failure in writeback by adding a mempool and passing in gfp_t flags to the rolling buffer functions that allocate memory, using the mempool if gfp != GFP_KERNEL. This is then extended upwards and the gfp to be used for a request is stored in the netfs_io_request struct and is then used for both requests and subrequests, eliminating the sleeping loops there. The failure caused: folio != NULL WARNING: fs/netfs/write_issue.c:603 at netfs_writepages+0x883/0xa10 fs/netfs/write_issue.c:603, CPU#3: syz.0.17/5919 Fixes: cd0277ed0c18 ("netfs: Use new folio_queue data type and iterator instead of xarray iter") Reported-by: syzbot+0da43efa72f88bd3a8af@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=0da43efa72f88bd3a8af Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260727130716.1099906-5-dhowells@redhat.com Tested-by: syzbot+0da43efa72f88bd3a8af@syzkaller.appspotmail.com cc: Paulo Alcantara <pc@manguebit.org> cc: Yun Zhou <yun.zhou@windriver.com> cc: Matthew Wilcox <willy@infradead.org> cc: Christoph Hellwig <hch@infradead.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-09netfs: release readahead folios on iterator preparation failureYichong Chen1-1/+3
[ Upstream commit 87eb3d272dcbcbbfe5c1576c10e5dc72810cf1f6 ] netfs_prepare_read_iterator() batches readahead folios in put_batch so that the folio references can be dropped after the I/O iterator has been prepared. If rolling_buffer_load_from_ra() fails after earlier folios have been batched, the function returns immediately and leaves those references held. Release the batch before returning the error. Fixes: 06fa229ceb36 ("netfs: Abstract out a rolling folio buffer implementation") Signed-off-by: Yichong Chen <chenyichong@uniontech.com> Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260727130716.1099906-4-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-09netfs: handle single writeback rolling buffer allocation failureYichong Chen1-1/+6
[ Upstream commit 37a1c535c80c67d98668d190c7432f9ebda43310 ] netfs_write_folio_single() takes an extra folio reference before appending the folio to the rolling buffer. rolling_buffer_append() can fail if it cannot allocate another folio_queue. Check the return value and drop the extra folio reference before returning the error. Fixes: 49866ce7ea8d ("netfs: Add support for caching single monolithic objects such as AFS dirs") Signed-off-by: Yichong Chen <chenyichong@uniontech.com> Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260727130716.1099906-3-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-09netfs: clear PG_private_2 on copy-to-cache append failureYichong Chen1-0/+1
[ Upstream commit a81fc9266e1c5fef9ccf675a9b44b2f4ab464923 ] netfs_pgpriv2_copy_to_cache() marks the folio with PG_private_2 before netfs_pgpriv2_copy_folio() appends it to the copy-to-cache rolling buffer. If the append fails, the folio is not queued for cache writeback, so the PG_private_2 state and its reference must be released immediately. Fixes: e2d46f2ec332 ("netfs: Change the read result collector to only use one work item") Signed-off-by: Yichong Chen <chenyichong@uniontech.com> Signed-off-by: David Howells <dhowells@redhat.com> Link: https://patch.msgid.link/20260727130716.1099906-2-dhowells@redhat.com cc: Paulo Alcantara <pc@manguebit.org> cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-09erofs: ensure valid f_path for page cache sharingGao Xiang3-32/+31
[ Upstream commit 96b2dbbe58a1ea5df8d29c2fe24b5f04715f4443 ] Previously, backing files for page cache sharing were set up with f_path left as NULL (only f_inode was valid). It worked, but a recent mincore fix relies on f_path.mnt and crashes (found by "erofs/028" on 7.2-rc4): BUG: kernel NULL pointer dereference, address: 0000000000000018 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP PTI CPU: 3 UID: 0 PID: 675528 Comm: fincore Not tainted 7.2.0-rc4-00002-g[]-dirty #1 PREEMPT(lazy) Hardware name: Red Hat KVM, BIOS 1.16.0-4.al8 04/01/2014 RIP: 0010:__do_sys_mincore+0xc0/0x2c0 ... Specify valid paths using valid disconnected dentries together with erofs_ishare_mnt instead of leaving f_path empty, so they are more like real backing files in a pseudo filesystem and standard backing_file_open() can be used directly. Fixes: e187bc02f8fa ("mm: do file ownership checks with the proper mount idmap") Acked-by: Hongbo Li <hongbohbli@tencent.com> Signed-off-by: Gao Xiang <xiang@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-09erofs: remove fscache backend entirelyGao Xiang9-841/+23
[ Upstream commit c37460cd9b2fcb61ec66b7eb4fde737e65ec2a56 ] EROFS over fscache was introduced to provide image lazy pulling functionality. After the feature landed, the fscache subsystem made netfs a new hard dependency, which is unexpected for a local filesystem and has an kernel-defined caching hierarchy which could be inflexible compared to the fanotify pre-content hooks. Therefore, this feature has been deprecated for almost two years. As EROFS file-backed mounts and fanotify pre-content hooks both upstream for a while and already providing equivalent functionality (erofs-utils has supported fanotify pre-content hooks), let's remove the fscache backend now. The main application of this feature is Nydus [1], and they plan to move to use fanotify pre-content hooks in the near future too. I hope this patch can be merged into Linux 7.2, which is also motivated by newly found implementation issues [2][3] that are not worth investigating given the deprecation and limited development resources. The associated fscache/cachefiles cleanup patch will follow separately through the vfs tree (netfs) later: it seems fine since the codebase is isolated by CONFIG_CACHEFILES_ONDEMAND. [1] https://github.com/dragonflyoss/nydus/blob/v2.1.0/docs/nydus-fscache.md [2] https://github.com/dragonflyoss/nydus/pull/1824 [3] https://lore.kernel.org/r/20260619135800.1594811-1-michael.bommarito@gmail.com Acked-by: Jingbo Xu <jefflexu@linux.alibaba.com> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com> Stable-dep-of: 96b2dbbe58a1 ("erofs: ensure valid f_path for page cache sharing") Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-09erofs: clean up erofs_ishare_fill_inode()Gao Xiang2-26/+21
[ Upstream commit 1ccc75909ca7c3b52163b408a3e1eb5453db013f ] - Use the shorthand `si` to replace the overly long `sharedinode`; - Introduce erofs_warn() and get rid of barely-used _erofs_printk(); - Get rid of the variable `hash`; - Simplify error paths. Reviewed-by: Hongbo Li <lihongbo22@huawei.com> Reviewed-by: Chao Yu <chao@kernel.org> Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com> Stable-dep-of: 96b2dbbe58a1 ("erofs: ensure valid f_path for page cache sharing") Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-09smb: client: fix buffer leaks in SMB1 read and writeDawei Feng1-3/+9
[ Upstream commit 6a3e16d60e81a4aa3056ab15617036cfbea2e07d ] CIFSSMBRead(), CIFSSMBWrite() and CIFSSMBWrite2() allocate a request buffer before checking whether tcon->ses->server is NULL. If that defensive check ever fails, the helper returns -ECONNABORTED without releasing the request buffer. Fix these leaks by releasing the allocated request buffer before returning from these error paths. Use cifs_small_buf_release() for the buffers allocated by small_smb_init() and cifs_buf_release() for the buffer allocated by smb_init(). The bug was first flagged by an experimental analysis tool we are developing for kernel memory-management bugs while analyzing v6.13-rc1. The tool is still under development and is not yet publicly available. Manual inspection confirms that the bug is still present in v7.1.1. An x86_64 allyesconfig build showed no new warnings. Runtime validation used a temporary fault-injection hook to force tcon->ses->server to NULL after request-buffer initialization. On the unfixed kernel, the harness observed two leaked small request buffers and one leaked large request buffer, with directed kmemleak dumps confirming the CIFS buffer allocation stacks. After the fix, no CIFS request-buffer deltas remained. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Dawei Feng <dawei.feng@seu.edu.cn> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-09ntfs: drop stale page-cache when shrinking a non-resident attrNamjae Jeon1-0/+10
[ Upstream commit 4e646ecd44759e552b0b9ccd995f3f608daab414 ] ntfs_non_resident_attr_shrink() shrinks attribute sizes but fails to trim the page cache. This leaves orphaned dirty folios beyond the new end of the attribute, leading to writeback failures (-ENOENT), data loss, and $EA chain corruption. Fix this by truncating the page cache to the new size immediately after updating the sizes, preventing writeback from flushing out-of-range folios. Fixes: 495e90fa3348 ("ntfs: update attrib operations") Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-09ntfs: harden runlist realloc size calculationsNamjae Jeon1-23/+27
[ Upstream commit 8bed376124ab4505b70083a2b91f2c7ef6d51e24 ] Add a shared helper to safely convert runlist element counts to byte sizes using overflow checks, and use it in both ntfs_rl_realloc() and ntfs_rl_realloc_nofail(). Fixes: 11ccc9107dc4 ("ntfs: update runlist handling and cluster allocator") Co-developed-by: Alper Mudar <kommandant_alper@proton.me> Signed-off-by: Alper Mudar <kommandant_alper@proton.me> Tested-by: Alper Mudar <kommandant_alper@proton.me> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-09btrfs: zoned: skip fully truncated ordered extents at zone finishJohannes Thumshirn1-0/+10
[ Upstream commit ab602da96a915d42dcb1b0b322e8daea0f71b51f ] A fully truncated ordered extent (truncated_len == 0) wrote no data, so its ->csum_list is empty and btrfs_finish_ordered_zoned() trips: assertion failed: !list_empty(&ordered->csum_list), in fs/btrfs/zoned.c:2141 Since commit 66ff4d366e7e a short or cancelled direct IO write finishes the unsubmitted ordered extent as truncated with uptodate = true instead of setting BTRFS_ORDERED_IOERR, so it now reaches btrfs_finish_ordered_zoned() rather than being skipped by the IOERR check in btrfs_finish_ordered_io(). generic/208 hits this on a zoned filesystem. Return early for these, like the BTRFS_ORDERED_PREALLOC case; there is no zone append result to record and btrfs_finish_one_ordered() skips them too. Fixes: 66ff4d366e7e ("btrfs: fix false IO failure after falling back to buffered write") Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-09btrfs: raid56: fix an incorrect csum skip during scrubQu Wenruo1-1/+3
[ Upstream commit 330dcc553f282e8dc0b88c9495b4c296465364e1 ] Commit 7425a2894019 ("btrfs: introduce btrfs_bio_for_each_block_all() helper") uses the new helper to replace the nested loop inside verify_bio_data_sectors(), which simplifies the code. However that also changed the behavior of "continue" when a block has no data checksum. Previously the "continue" would skip the old for() loop, which would also increase @total_sector_nr. Now the "continue" will skip the new btrfs_bio_for_each_block_all() loop, which doesn't update @total_sector_nr. This means if we hit a block that has no data checksum, we will skip all the remaining blocks no matter if they have data checksum. As @total_sector_nr will never be updated, and that test_bit() will always return false. Fix it by increasing @total_sector_nr before calling "continue". Fixes: 7425a2894019 ("btrfs: introduce btrfs_bio_for_each_block_all() helper") Reviewed-by: Daniel Vacek <neelx@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-09btrfs: skip global block reserve accounting for rescue mountsDongjiang Zhu3-12/+27
[ Upstream commit 51a0e8399858621442807a26057bcd1cd3ced046 ] [BUG] Mounting with rescue=ibadroots after corrupting the block group tree root triggers a NULL pointer dereference: BUG: kernel NULL pointer dereference, address: 0000000000000100 RIP: 0010:btrfs_update_global_block_rsv+0x9d/0x1c0 [btrfs] Call Trace: fill_dummy_bgs+0xd4/0x120 [btrfs] open_ctree+0xc6e/0x1ca0 [btrfs] btrfs_get_tree+0x50d/0xa40 [btrfs] The same crash occurs with a corrupted raid stripe tree root, via btrfs_read_block_groups() instead of fill_dummy_bgs(). [CAUSE] With rescue=ibadroots, btrfs_read_roots() allows the mount to continue when either root cannot be read, leaving the corresponding root pointer NULL while its on-disk feature bit remains set. btrfs_update_global_block_rsv() then dereferences the missing root based on the feature bit alone. [FIX] Rescue mounts are fully read-only and cannot start transactions, so the global reserve is never consumed. Under btrfs_is_full_ro(), mark the reserve as full and return before performing the accounting. And since we need to check if the fs is mount fully RO, export fs_is_full_ro() as btrfs_is_full_ro(), and move it to fs.h. Fixes: 8dbfc14fc736 ("btrfs: account block group tree when calculating global reserve size") Fixes: 515020900d44 ("btrfs: read raid stripe tree from disk") Suggested-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Dongjiang Zhu <zhudongjiang@fnnas.com> [ Squash the fs_is_full_ro() export commit into this one. ] Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-09btrfs: warn about extent buffer that can not be releasedQu Wenruo3-8/+57
[ Upstream commit 83f7e52b7ed1c3e03b79123e20b6f6adf8d886bb ] When we unmount the fs or during mount failures, btrfs will call invalidate_inode_pages() to release all btree inode folios. However that function can return -EBUSY if any folios can not be invalidated. This can be caused by: - Some extent buffers are still held by btrfs This is a logic error, as we should release all tree root nodes during unmount and mount failure handling. - Some extent buffers are under readahead and haven't yet finished These are much rarer but valid cases. In that case we should wait for those extent buffers. Introduce a new helper invalidate_and_check_btree_folios() which will: - Call invalidate_inode_pages2() and catch its return value If it returned 0 as expected, that's great and we can call it a day. - Otherwise go through each extent buffer in buffer_tree Increase the ref by one first for the eb we're checking. This is to ensure the eb won't be freed after the readahead is finished. For ebs that still have EXTENT_BUFFER_READING flag, wait for them to finish first. After waiting for the readahead, check the refs of the eb and if it's still dirty. If the eb ref count is greater than 2 (one for the buffer tree, one held by us), it means we are still holding the extent buffer somewhere else, which is a code bug. If the eb is still dirty, it means a bug in transaction handling, e.g. the bug fixed by patch "btrfs: only release the dirty pages io tree after successful writes". For either case, show a warning message about the eb, including its bytenr, owner, refs and flags. And if it's a debug build, also trigger WARN_ON_ONCE() so that fstests can properly catch such situation. Link: https://bugzilla.kernel.org/show_bug.cgi?id=221270 Reported-by: AHN SEOK-YOUNG <iamsyahn@gmail.com> CC: Teng Liu <27rabbitlt@gmail.com> Tested-by: Teng Liu <27rabbitlt@gmail.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Stable-dep-of: 51a0e8399858 ("btrfs: skip global block reserve accounting for rescue mounts") Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-09btrfs: zoned: reset meta_write_pointer on zone resetJohannes Thumshirn1-0/+11
[ Upstream commit 5fabb1cf25d723274009d7b759545fd59f230c9d ] btrfs_reset_unused_block_groups() resets a block group's zone and sets alloc_offset back to 0 so the space can be reused, but it leaves meta_write_pointer pointing at the previous end of the zone. Once the block group is reactivated and reused for metadata, newly allocated tree blocks live before that stale write pointer. btrfs_check_meta_write_pointer() then sees them behind the write pointer, so they can never be written out in sequential order: the dirty extent buffers are stranded and pin their btree_inode folios until unmount. Reset meta_write_pointer back to the start of the block group for metadata and system block groups. Fixes: 453a73c3069a ("btrfs: zoned: reclaim unused zone by zone resetting") Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-09btrfs: zoned: fix deadlock between metadata writeback and transaction commitJohannes Thumshirn1-1/+5
[ Upstream commit 1ebe51c29fa9755d5b2fea28727c051117907cf8 ] When writing out metadata extent buffers in a zoned filesystem, btree_writepages() holds fs_info->zoned_meta_io_lock across the whole writeback loop, including the call to btrfs_check_meta_write_pointer() -> check_bg_is_active(). For the tree-log block group, check_bg_is_active() may fail to activate the zone and fall back to btrfs_zone_finish_one_bg() to free an active zone. That path waits for the running transaction to commit while still holding zoned_meta_io_lock, but the committer needs that same lock to write out the tree extents, so the two tasks deadlock: Task A (kworker, metadata writeback) Task B (fsstress, transaction commit) ------------------------------------ ------------------------------------- wb_workfn() btrfs_commit_transaction(T) btree_writepages() btrfs_write_and_wait_transaction() btrfs_zoned_meta_io_lock() btrfs_write_marked_extents() btrfs_check_meta_write_pointer() btree_writepages() check_bg_is_active() [treelog_bg] btrfs_zoned_meta_io_lock() btrfs_zone_finish_one_bg() <blocks on zoned_meta_io_lock, btrfs_zone_finish() held by Task A> do_zone_finish() btrfs_inc_block_group_ro() btrfs_wait_for_commit() <blocks waiting for commit of transaction T, done by Task B> The sibling branch in check_bg_is_active() already drops zoned_meta_io_lock around do_zone_finish() for this exact reason. Do the same in the tree-log branch: release the lock around btrfs_zone_finish_one_bg() and re-acquire it afterwards. The lock only protects fs_info->active_{meta,system}_bg, which this branch does not touch, and ctx->zoned_bg keeps a reference to the block group across the unlock, so nothing is lost while the lock is dropped. This hang occasionally reproduces with fstests generic/475 on a zoned btrfs filesystem. Fixes: 13bb483d32ab ("btrfs: zoned: activate metadata block group on write time") Reviewed-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-09btrfs: fix leaking BTRFS_FS_STATE_REMOUNTING flagQu Wenruo1-3/+5
[ Upstream commit 6881f45d0eb541f2cee8c37c84b3860a23823bb3 ] [BUG] The following script can lead to unexpected qgroup rescan failure: # mkfs.btrfs -f -O quota $dev # mount $dev $mnt # mount -o remount,rescue=ibadroots $mnt ^^^^^ This above command is expected to fail # btrfs quota rescan -w $mnt ^^^^^ The above qgroup rescan is not expected to fail # btrfs qgroup show $mnt WARNING: qgroup data inconsistent, rescan recommended Qgroupid Referenced Exclusive Path -------- ---------- --------- ---- 0/5 16.00KiB 16.00KiB <toplevel> The above short script will be converted to a proper fstests case. [CAUSE] Inside btrfs_reconfigure(), if either btrfs_check_options() or btrfs_check_features() failed, we will always have BTRFS_FS_STATE_REMOUNTING set for the fs until the next successful remount. That BTRFS_FS_STATE_REMOUNTING flag will interrupt several operations, including: - Qgroup rescan - Auto defrag - Space reclaim [FIX] Change the error handling of btrfs_check_options() and btrfs_check_features() to goto restore label. Fixes: eddb1a433f26 ("btrfs: add reconfigure callback for fs_context") Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-09ntfs: preserve RECALL_ON_OPEN on WSL special-file reparse pointsNamjae Jeon1-1/+2
[ Upstream commit 523307b8516fc740895238af8473aa0630b3e088 ] When creating a WSL special file (socket, fifo, character or block device), __ntfs_create() sets FILE_ATTRIBUTE_RECALL_ON_OPEN in ni->flags as valid_reparse_data() requires for these tags. This flag is intentionally absent from $FILE_NAME, so the subsequent reload ni->flags = fn->file_attributes; drops it from ni->flags, the authoritative copy written back to $STANDARD_INFORMATION. The on-disk file_attributes becomes 0x00000404 instead of 0x00040404, and after a remount valid_reparse_data() rejects the reparse point while fsck reports "$REPARSE_POINT data is corrupted". Preserve the RECALL_ON_OPEN bit across the reload. Symlinks do not set that bit, so they are unaffected. Fixes: af0db57d4293 ("ntfs: update inode operations") Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-03cifs: consolidate time_last_write stamp into _cifsFileInfo_put()Frank Sorenson2-66/+22
commit 0e3ea5445c228048f937ad5a944c27859a78f971 upstream. The time_last_write stamp was scattered across cifs_close(), smb2_deferred_work_close(), and the three drain functions in misc.c. This missed the case where background I/O holds the final reference after userspace close() returns, and required explicit maintenance at each close-path site. Move the smp_store_release() into _cifsFileInfo_put(), immediately before releasing open_file_lock. This single location covers all close paths unconditionally: normal close, background I/O dropping the final reference, deferred close via timer or external drain. The spinlock's store-release/load-acquire pairing with is_inode_writable() already provides the ordering guarantee documented in is_size_safe_to_change(). Remove the now-redundant stamps from cifs_close(), smb2_deferred_work_close(), and all six stamp sites in the misc.c deferred-close drain functions. Fixes: e8a8d54c2d50 ("cifs: prevent readdir from changing file size due to stale directory metadata") Signed-off-by: Frank Sorenson <sorenson@redhat.com> Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Signed-off-by: Steve French <stfrench@microsoft.com> Cc: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-03cifs: fix time_last_write stamp placement in setattr/truncate pathsFrank Sorenson1-4/+22
commit ecababf08905958ba8c125979c4e39fc2f1a8a05 upstream. cifs_file_set_size() calls cifs_setsize() on success, which calls i_size_write(), updating i_size to the new value. The subsequent check attrs->ia_size != i_size_read() in both cifs_setattr_unix() and cifs_setattr_nounix() therefore always evaluates false after a successful cifs_file_set_size(), making the smp_store_release() of time_last_write dead code. The truncate path was unprotected against stale readdir size updates. Move the stamp to before the cifs_file_set_size() RPC call, guarded by attrs->ia_size != i_size_read() to exclude no-op same-size ftruncate(2) calls from stamping time_last_write unnecessarily. On the error path the stamp remains rather than being restored: restoring a stale snapshot (prev_tlw) could silently erase a concurrent _cifsFileInfo_put() close stamp if that close arrived between the READ_ONCE and the smp_store_release. readdir is suppressed until the stamp expires, which extends beyond one acregmax if the caller retries failed truncations. stat() is unaffected: the cifs_revalidate_dentry_attr() path calls cifs_fattr_to_inode() with from_readdir=false, which bypasses the time_last_write check in is_size_safe_to_change() entirely and always writes the authoritative QUERY_INFO result to i_size. Remove the now-unreachable stamp from the dead block in both functions. Fixes: e8a8d54c2d50 ("cifs: prevent readdir from changing file size due to stale directory metadata") Signed-off-by: Frank Sorenson <sorenson@redhat.com> Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Signed-off-by: Steve French <stfrench@microsoft.com> Cc: Jiri Slaby <jirislaby@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-03SUNRPC: Return an error from xdr_buf_to_bvec() on overflowChuck Lever1-1/+5
[ Upstream commit 18c1cc69886192e33536498289d26dba6894e3d5 ] xdr_buf_to_bvec() returns a slot count even when the caller's bvec budget is exhausted partway through the xdr_buf. Callers feed that count into iov_iter_bvec() and continue as if the conversion had succeeded, silently sending or writing fewer bytes than the data length declares. For an NFS WRITE the server reports the truncated transfer to the client as full success. The overflow represents an internal invariant violation: a higher layer reserved a bvec budget too small for the xdr_buf it then asked the encoder to convert. That is a server-side fault, not a media I/O failure and not a malformed client argument. Change xdr_buf_to_bvec() to return a signed int and have the overflow label return -ESERVERFAULT. Update the three callers to detect the negative return and fail the request: nfsd_vfs_write() folds the error into host_err, which nfserrno() translates to nfserr_serverfault for the WRITE reply; svc_udp_sendto() and svc_tcp_sendmsg() propagate the error out of the send path. Reported-by: Chris Mason <clm@meta.com> Fixes: 2eb2b9358181 ("SUNRPC: Convert svc_tcp_sendmsg to use bio_vecs directly") Cc: stable@vger.kernel.org Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-03xfs: don't replace the wrong part of the cow forkDarrick J. Wong2-83/+148
[ Upstream commit a1caeeadbf57ff86dfc3454398c46de86056a74e ] LOLLM points out that xfs_iext_lookup_extent can return a @got where got->br_startoff < startoff. In this case, xrep_cow_replace_range replaces the entire mapping instead of just the part that had been marked bad in the bitmap, but advances the bitmap cursor in xrep_cow_replace by the amount replaced. As a result, we fail to replace the end of the bad range, and replace part of the good range. Fix this by rewriting the replace method to handle replacing the middle of a cow fork mapping. This we do by returning both the current mapping as @got, and the subset of the mapping that we want to replace as @rep, using @rep to store the results of the new allocation, and comparing @rep to @got to figure out the exact transformations needed. Cc: stable@vger.kernel.org # v6.8 Fixes: dbbdbd0086320a ("xfs: repair problems in CoW forks") Signed-off-by: "Darrick J. Wong" <djwong@kernel.org> Assisted-by: LOLLM # finding obvious bugs Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Carlos Maiolino <cem@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-03fuse-uring: fix race between registration and connection abortionJoanne Koong1-6/+16
[ Upstream commit 952b5d36f6a298f57c52a59e72076c69386a8aaf ] This fixes this race: - thread a: io_uring_enter -> register sqe -> fuse_uring_create_ring_ent -> allocate ent but doesn't grab queue_ref yet - thread b: fuse_conn_destroy() -> fuse_chan_abort() -> fuse_uring_abort() is a no-op due to queue ref being 0 - thread a: grabs the queue_ref, queue_ref is now 1, rest of fuse_uring_do_register() logic executes - thread b: fuse_chan_abort() returns, fuse_chan_wait_aborted() now runs and calls "wait_event(ring->stop_waitq, atomic_read(&ring->queue_refs) == 0);" The abort/unmount thread will hang indefinitely in unkillable state as nothing will decrement queue_refs or wake stop_waitq, and the ring, queue, and ent are leaked. Fix this by checking fch->connected under fch->lock after the created ent has grabbed a ref count on the queue. This ensures that in the scenario above, it is guaranteed that we either release the queue ref and wake up stop_waitq (in case fuse_chan_wait_aborted() is already waiting) in fuse_uring_do_register() when we detect !fch->connected, or if the connection is aborted after the check, it is guaranteed that the async teardown worker will be running in the background cleaning up ents and decrementing the ent's ref on the queue, which will unblock the eventual queue and ring teardown. Fixes: 24fe962c86f5 ("fuse: {io-uring} Handle SQEs - register commands") Cc: stable@vger.kernel.org Reviewed-by: Bernd Schubert <bernd@bsbernd.com> Signed-off-by: Joanne Koong <joannelkoong@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> [ changed fch->lock/fch->connected references to fc->lock/fc->connected since struct fuse_chan does not exist in this tree ] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-03ksmbd: validate ACE size against SID sub-authoritiesNamjae Jeon1-3/+10
commit 5152c6d49e3fd4e9f2e857c57527aead752f1f87 upstream. set_ntacl_dacl() validates sid.num_subauth before copying an ACE, but does not verify that the declared ACE size contains all sub-authorities described by that field. An undersized ACE can therefore be copied and later make the POSIX ACL deduplication walk inspect data beyond the copied ACE boundary. The existing initial bound check is also too small. It only ensures that the ACE size field is accessible before set_ntacl_dacl() reads sid.num_subauth farther into the input buffer. Require enough input for the fixed SID header before accessing num_subauth, reject ACEs smaller than that header, and skip ACEs whose declared size cannot contain the complete SID. This makes the validation consistent with the other ACE walk paths. Reported-by: LocalHost <localhost.detect@gmail.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Wentao Guan <guanwentao@uniontech.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-03ksmbd: bound DACL dedup walk to copied ACEsNamjae Jeon1-6/+10
commit 58d97fcd0bf1aee694e244cc28635b9df95b543b upstream. set_ntacl_dacl() can stop copying ACEs before consuming the full input DACL when size accounting overflows. When that happens, num_aces reflects only the ACEs that were actually copied into the output DACL, but set_posix_acl_entries_dacl() still receives nt_num_aces and uses it to walk the existing ACE array during dedup. That makes the dedup walk scan past the copied ACE array and inspect buffer tail that does not contain valid ACEs. Split the two meanings currently carried by the NT ACE count. Pass the number of copied NT ACEs to bound the dedup walk, and preserve the original "input DACL had NT ACEs" state separately for the Everyone/default ACL fallback. This keeps the dedup walk aligned with the ACEs that are actually present in the rebuilt DACL. Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Wentao Guan <guanwentao@uniontech.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-03ksmbd: restore DACL size on check_add_overflow() to avoid malformed ACLWentao Guan1-1/+6
commit bbf0a8e931204ecdab494a88d43b0a24a04285c5 upstream. check_add_overflow() unconditionally writes the truncated sum into *d even on overflow, per its contract in include/linux/overflow.h. The four check_add_overflow() guards in set_posix_acl_entries_dacl() and set_ntacl_dacl() break out of the ACE-building loops on overflow, but the truncated *size is then consumed downstream at the end of set_ntacl_dacl(): pndacl->size = cpu_to_le16(le16_to_cpu(pndacl->size) + size); This produces an on-wire NT ACL whose pndacl->size under-reports the bytes actually written by the preceding fill_ace_for_sid()/memcpy() calls, yielding a malformed ACL that can trigger out-of-bounds reads when re-parsed by clients or ksmbd itself. Restore *size to its pre-addition value on each overflow branch (via `*size -= ace_sz` / `size -= nt_ace_size`) so that after the break, *size once again holds the cumulative size of the successfully-written ACEs. The committed ACL is then truncated-but-self-consistent rather than malformed. The ksmbd DACL builders are the only check_add_overflow() sites found where an overflow path breaks out of a loop and the destination value is consumed afterward. The other nearby break-style cases either return -EINVAL on overflow (transport_ipc.c) or break without consuming the overflowed destination value afterward (buildid.c). Fixes: 299f962c0b02 ("ksmbd: use check_add_overflow() to prevent u16 DACL size overflow") Assisted-by: atomcode:glm-5.2 Assisted-by: Codex:gpt-5.5 Cc: stable@vger.kernel.org Signed-off-by: Wentao Guan <guanwentao@uniontech.com> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-03ksmbd: validate num_subauth when copying ACE in set_ntacl_daclHaofeng Li1-1/+7
commit 47f0b34f6bc98ed85bfdc293e8f3e432ec24958d upstream. set_ntacl_dacl() copies each ACE from the attacker-controlled stored security descriptor verbatim into the response DACL without checking sid.num_subauth. The ACE bytes (including an unchecked num_subauth) originate from an authenticated SMB2_SET_INFO(SecInfo=DACL) that is stored raw via ksmbd_vfs_set_sd_xattr(); parse_dacl() rejects a bad ACE with `break` rather than an error, so parse_sec_desc() still returns success and the malformed SD reaches the xattr intact. On a subsequent SMB2_QUERY_INFO(SecInfo=DACL) for an inode carrying a POSIX access ACL, build_sec_desc() -> set_ntacl_dacl() -> set_posix_acl_entries_dacl() walks the copied ACEs and reads ntace->sid.sub_auth[ntace->sid.num_subauth - 1] with num_subauth taken straight from the stored SD. Since sub_auth[] is fixed at SID_MAX_SUB_AUTHORITIES (15), a crafted num_subauth (e.g. 255) drives an out-of-bounds heap read of ~1 KB with an offset fully controlled by an authenticated client. The sibling functions already gate this field: parse_dacl() -- num_subauth == 0 || > SID_MAX_SUB_AUTHORITIES parse_sid() -- num_subauth > SID_MAX_SUB_AUTHORITIES smb_copy_sid() -- min_t(u8, num_subauth, SID_MAX_SUB_AUTHORITIES) set_ntacl_dacl() is the lone inconsistent path that omits the check. Add the same num_subauth validation in set_ntacl_dacl() before copying the ACE, matching the gate already enforced by parse_dacl(). Signed-off-by: Haofeng Li <lihaofeng@kylinos.cn> Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Suggested-by: Namjae Jeon <linkinjeon@kernel.org> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Wentao Guan <guanwentao@uniontech.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-08-03ksmbd: validate minimum PDU size for transform requestsNamjae Jeon1-5/+11
commit cfc0b8e5080aec87700774e8568765eaa4b7b92b upstream. The receive path applies the minimum SMB2 PDU size check only when ProtocolId is SMB2_PROTO_NUMBER. A packet carrying SMB2_TRANSFORM_PROTO_NUM bypasses the check even when the negotiated dialect does not provide transform handling. On an SMB 2.1 connection, a short transform packet therefore reaches init_smb2_rsp_hdr(), which interprets the request as a full SMB2 header and reads beyond the request allocation. The copied fields can then be returned to the unauthenticated client. Compression transforms are converted to ordinary SMB2 messages before protocol validation. After that conversion, validate ordinary SMB2 requests against SMB2_MIN_SUPPORTED_PDU_SIZE and require encryption transform requests to contain both a transform header and an SMB2 header. This rejects truncated requests before work allocation. Fixes: 368ba06881c3 ("ksmbd: check the validation of pdu_size in ksmbd_conn_handler_loop") Cc: stable@vger.kernel.org Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-31063 Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-03ksmbd: defer destroy_previous_session() until after NTLM authenticationJames Montgomery1-5/+4
commit c74801ee524f477c174a1899782b6c3b6918d407 upstream. In ntlm_authenticate(), destroy_previous_session() is called using a user pointer resolved from the client-supplied NTLM blob username field before the NTLMv2 response is validated. An authenticated attacker can set the NTLM blob username to match a victim account and set PreviousSessionId to the victim's session ID; destroy_previous_session() destroys the victim's session while ksmbd_decode_ntlmssp_auth_blob() subsequently rejects the request with -EPERM. Move destroy_previous_session() and the prev_id assignment to after ksmbd_decode_ntlmssp_auth_blob() returns success and use sess->user rather than the pre-authentication lookup result. This matches the ordering already used by krb5_authenticate(), where destroy_previous_session() is called only after ksmbd_krb5_authenticate() returns success. Fixes: e2f34481b24d ("cifsd: add server-side procedures for SMB3") Cc: stable@vger.kernel.org Link: https://lore.kernel.org/linux-cifs/20260702155449.3639773-1-james_montgomery@disroot.org/ Signed-off-by: James Montgomery <james_montgomery@disroot.org> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-08-03smb: client: handle STATUS_STOPPED_ON_SYMLINK responses without a symlink targetCarl Johnson2-3/+41
commit 2eb74eef4b7eda8df593d22fb48e94ef959ec8a5 upstream. The macOS built-in SMB server returns STATUS_STOPPED_ON_SYMLINK for a CREATE on a path whose final component is a symlink, but it does not include a Symbolic Link Error Response in the error data: both ErrorContextCount and ByteCount are zero, so the symlink target is not present in the response at all. Per [MS-SMB2] section 2.2.2 such a response should carry a valid Symbolic Link Error Response, so this is a server bug, but the target can still be retrieved with FSCTL_GET_REPARSE_POINT. Frame from a capture against macOS 26.5.2 (build 25F84): SMB2 hdr : Status=0x8000002d STATUS_STOPPED_ON_SYMLINK, Cmd=Create Error Rsp: StructureSize=0x0009 Error Context Count: 0 Byte Count: 0 Error Data: 00 symlink_data() cannot find a struct smb2_symlink_err_rsp in such a response and returns -EINVAL, which parse_create_response() propagates, so smb2_query_path_info() bails out at if (rc || !data->reparse_point) goto out; before it can retry with SMB2_OP_GET_REPARSE. stat(), readlink() and ls of any server-side symlink then fail with -EINVAL: $ ls -la Config l????????? ? ? ? ? ? Config.json $ stat Config/Config.json stat: cannot statx 'Config/Config.json': Invalid argument A 5.10 client resolves these symlinks correctly against the same server and share, so this is a regression for Apple SMB servers. Handle it in several places: - symlink_data() detects the empty response (ErrorContextCount and ByteCount both zero) and returns a distinct -ENODATA, so that "server did not send the target" can be told apart from a genuinely malformed response and only this case is worked around. - parse_create_response() treats -ENODATA like STATUS_IO_REPARSE_TAG_NOT_HANDLED, which does not carry the target either: leave the reparse tag unset and clear rc, so the existing SMB2_OP_GET_REPARSE path retrieves the target. - smb2_query_path_info() only fixes up the symlink target type when the target is already known. SMB2_OP_GET_REPARSE sets data->reparse.tag but does not parse the target out of the reparse buffer; that happens later, in reparse_info_to_fattr(). Without this check smb2_fix_symlink_target_type() is called with a NULL target and returns -EIO. This could not happen with servers that send the target inline and therefore skip SMB2_OP_GET_REPARSE. - smb2_open_file() maps -ENODATA to -EIO, matching STATUS_IO_REPARSE_TAG_NOT_HANDLED, so its callers retrieve the target with SMB2_OP_GET_REPARSE as well. Tested on Debian 13, kernel 6.18.38 (armv7), against macOS 26.5.2: symlinks now resolve, including relative, parent-traversing and directory symlinks, and reads through symlinks succeed. Cc: stable@vger.kernel.org Co-developed-by: Pali Rohár <pali@kernel.org> Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Carl Johnson <carl@jpartners.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>