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2026-03-04cifs: some missing initializations on replayShyam Prasad N2-0/+3
[ Upstream commit 14f66f44646333d2bfd7ece36585874fd72f8286 ] In several places in the code, we have a label to signify the start of the code where a request can be replayed if necessary. However, some of these places were missing the necessary reinitializations of certain local variables before replay. This change makes sure that these variables get initialized after the label. Cc: stable@vger.kernel.org Reported-by: Yuchan Nam <entropy1110@gmail.com> Tested-by: Yuchan Nam <entropy1110@gmail.com> Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04cifs: Fix locking usage for tcon fieldsShyam Prasad N5-10/+11
[ Upstream commit 96c4af418586ee9a6aab61738644366426e05316 ] We used to use the cifs_tcp_ses_lock to protect a lot of objects that are not just the server, ses or tcon lists. We later introduced srv_lock, ses_lock and tc_lock to protect fields within the corresponding structs. This was done to provide a more granular protection and avoid unnecessary serialization. There were still a couple of uses of cifs_tcp_ses_lock to provide tcon fields. In this patch, I've replaced them with tc_lock. Cc: stable@vger.kernel.org Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04smb: client: prevent races in ->query_interfaces()Henrique Carvalho1-11/+8
[ Upstream commit c3c06e42e1527716c54f3ad2ced6a034b5f3a489 ] It was possible for two query interface works to be concurrently trying to update the interfaces. Prevent this by checking and updating iface_last_update under iface_lock. Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04smb: client: add proper locking around ses->iface_last_updateHenrique Carvalho1-0/+2
[ Upstream commit e97dcac3dc0bd37e4b56aaa6874b572a3a461102 ] There is a missing ses->iface_lock in cifs_setup_session, around ses->iface_last_update. Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04smb: client: correct value for smbd_max_fragmented_recv_sizeStefan Metzmacher1-2/+17
[ Upstream commit 4a93d1ee2d0206970b6eb13fbffe07938cd95948 ] When we download a file without rdma offload or get a large directly enumeration from the server, the server might want to send up to smbd_max_fragmented_recv_size bytes, but if it is too large all our recv buffers might already be moved to the recv_io.reassembly.list and we're no longer able to grant recv credits. The maximum fragmented upper-layer payload receive size supported Assume max_payload_per_credit is smbd_max_receive_size - 24 = 1340 The maximum number would be smbd_receive_credit_max * max_payload_per_credit 1340 * 255 = 341700 (0x536C4) The minimum value from the spec is 131072 (0x20000) For now we use the logic we used in ksmbd before: (1364 * 255) / 2 = 173910 (0x2A756) Fixes: 03bee01d6215 ("CIFS: SMBD: Add SMB Direct protocol initial values and constants") Cc: Steve French <smfrench@gmail.com> Cc: Tom Talpey <tom@talpey.com> Cc: Long Li <longli@microsoft.com> Cc: Namjae Jeon <linkinjeon@kernel.org> Cc: linux-cifs@vger.kernel.org Cc: samba-technical@lists.samba.org Signed-off-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-03-04smb: client: fix potential UAF and double free in smb2_open_file()Paulo Alcantara1-0/+2
[ Upstream commit ebbbc4bfad4cb355d17c671223d0814ee3ef4eda ] Zero out @err_iov and @err_buftype before retrying SMB2_open() to prevent an UAF bug if @data != NULL, otherwise a double free. Fixes: e3a43633023e ("smb/client: fix memory leak in smb2_open_file()") Reported-by: David Howells <dhowells@redhat.com> Closes: https://lore.kernel.org/r/2892312.1770306653@warthog.procyon.org.uk Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Reviewed-by: David Howells <dhowells@redhat.com> Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Cc: linux-cifs@vger.kernel.org Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-02-16smb: client: split cached_fid bitfields to avoid shared-byte RMW racesHenrique Carvalho1-4/+4
commit ec306600d5ba7148c9dbf8f5a8f1f5c1a044a241 upstream. is_open, has_lease and on_list are stored in the same bitfield byte in struct cached_fid but are updated in different code paths that may run concurrently. Bitfield assignments generate byte read–modify–write operations (e.g. `orb $mask, addr` on x86_64), so updating one flag can restore stale values of the others. A possible interleaving is: CPU1: load old byte (has_lease=1, on_list=1) CPU2: clear both flags (store 0) CPU1: RMW store (old | IS_OPEN) -> reintroduces cleared bits To avoid this class of races, convert these flags to separate bool fields. Cc: stable@vger.kernel.org Fixes: ebe98f1447bbc ("cifs: enable caching of directories for which a lease is held") Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-02-11smb/client: fix memory leak in smb2_open_file()ChenXiaoSong1-0/+1
[ Upstream commit e3a43633023e3cacaca60d4b8972d084a2b06236 ] Reproducer: 1. server: directories are exported read-only 2. client: mount -t cifs //${server_ip}/export /mnt 3. client: dd if=/dev/zero of=/mnt/file bs=512 count=1000 oflag=direct 4. client: umount /mnt 5. client: sleep 1 6. client: modprobe -r cifs The error message is as follows: ============================================================================= BUG cifs_small_rq (Not tainted): Objects remaining on __kmem_cache_shutdown() ----------------------------------------------------------------------------- Object 0x00000000d47521be @offset=14336 ... WARNING: mm/slub.c:1251 at __kmem_cache_shutdown+0x34e/0x440, CPU#0: modprobe/1577 ... Call Trace: <TASK> kmem_cache_destroy+0x94/0x190 cifs_destroy_request_bufs+0x3e/0x50 [cifs] cleanup_module+0x4e/0x540 [cifs] __se_sys_delete_module+0x278/0x400 __x64_sys_delete_module+0x5f/0x70 x64_sys_call+0x2299/0x2ff0 do_syscall_64+0x89/0x350 entry_SYSCALL_64_after_hwframe+0x76/0x7e ... kmem_cache_destroy cifs_small_rq: Slab cache still has objects when called from cifs_destroy_request_bufs+0x3e/0x50 [cifs] WARNING: mm/slab_common.c:532 at kmem_cache_destroy+0x16b/0x190, CPU#0: modprobe/1577 Link: https://lore.kernel.org/linux-cifs/9751f02d-d1df-4265-a7d6-b19761b21834@linux.dev/T/#mf14808c144448b715f711ce5f0477a071f08eaf6 Fixes: e255612b5ed9 ("cifs: Add fallback for SMB2 CREATE without FILE_READ_ATTRIBUTES") Reported-by: Paulo Alcantara <pc@manguebit.org> Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Reviewed-by: Pali Rohár <pali@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17smb/client: fix NT_STATUS_NO_DATA_DETECTED valueChenXiaoSong1-1/+1
[ Upstream commit a1237c203f1757480dc2f3b930608ee00072d3cc ] This was reported by the KUnit tests in the later patches. See MS-ERREF 2.3.1 STATUS_NO_DATA_DETECTED. Keep it consistent with the value in the documentation. Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17smb/client: fix NT_STATUS_DEVICE_DOOR_OPEN valueChenXiaoSong1-1/+1
[ Upstream commit b2b50fca34da5ec231008edba798ddf92986bd7f ] This was reported by the KUnit tests in the later patches. See MS-ERREF 2.3.1 STATUS_DEVICE_DOOR_OPEN. Keep it consistent with the value in the documentation. Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-17smb/client: fix NT_STATUS_UNABLE_TO_FREE_VM valueChenXiaoSong1-1/+1
[ Upstream commit 9f99caa8950a76f560a90074e3a4b93cfa8b3d84 ] This was reported by the KUnit tests in the later patches. See MS-ERREF 2.3.1 STATUS_UNABLE_TO_FREE_VM. Keep it consistent with the value in the documentation. Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-11cifs: Fix memory and information leak in smb3_reconfigure()Zilin Guan1-0/+2
[ Upstream commit cb6d5aa9c0f10074f1ad056c3e2278ad2cc7ec8d ] In smb3_reconfigure(), if smb3_sync_session_ctx_passwords() fails, the function returns immediately without freeing and erasing the newly allocated new_password and new_password2. This causes both a memory leak and a potential information leak. Fix this by calling kfree_sensitive() on both password buffers before returning in this error case. Fixes: 0f0e357902957 ("cifs: during remount, make sure passwords are in sync") Signed-off-by: Zilin Guan <zilin@seu.edu.cn> Reviewed-by: ChenXiaoSong <chenxiaosong@kylinos.cn> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2026-01-11smb: fix invalid username check in smb3_fs_context_parse_param()Yiqi Sun1-1/+1
[ Upstream commit ed6612165b74f09db00ef0abaf9831895ab28b7f ] Since the maximum return value of strnlen(..., CIFS_MAX_USERNAME_LEN) is CIFS_MAX_USERNAME_LEN, length check in smb3_fs_context_parse_param() is always FALSE and invalid. Fix the comparison in if statement. Signed-off-by: Yiqi Sun <sunyiqixm@gmail.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-12-07smb: client: fix memory leak in cifs_construct_tcon()Paulo Alcantara1-0/+1
commit 3184b6a5a24ec9ee74087b2a550476f386df7dc2 upstream. When having a multiuser mount with domain= specified and using cifscreds, cifs_set_cifscreds() will end up setting @ctx->domainname, so it needs to be freed before leaving cifs_construct_tcon(). This fixes the following memory leak reported by kmemleak: mount.cifs //srv/share /mnt -o domain=ZELDA,multiuser,... su - testuser cifscreds add -d ZELDA -u testuser ... ls /mnt/1 ... umount /mnt echo scan > /sys/kernel/debug/kmemleak cat /sys/kernel/debug/kmemleak unreferenced object 0xffff8881203c3f08 (size 8): comm "ls", pid 5060, jiffies 4307222943 hex dump (first 8 bytes): 5a 45 4c 44 41 00 cc cc ZELDA... backtrace (crc d109a8cf): __kmalloc_node_track_caller_noprof+0x572/0x710 kstrdup+0x3a/0x70 cifs_sb_tlink+0x1209/0x1770 [cifs] cifs_get_fattr+0xe1/0xf50 [cifs] cifs_get_inode_info+0xb5/0x240 [cifs] cifs_revalidate_dentry_attr+0x2d1/0x470 [cifs] cifs_getattr+0x28e/0x450 [cifs] vfs_getattr_nosec+0x126/0x180 vfs_statx+0xf6/0x220 do_statx+0xab/0x110 __x64_sys_statx+0xd5/0x130 do_syscall_64+0xbb/0x380 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: f2aee329a68f ("cifs: set domainName when a domain-key is used in multiuser") Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Reviewed-by: David Howells <dhowells@redhat.com> Cc: Jay Shin <jaeshin@redhat.com> Cc: stable@vger.kernel.org Cc: linux-cifs@vger.kernel.org Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-01smb: client: fix incomplete backport in cfids_invalidation_worker()Henrique Carvalho1-1/+1
The previous commit bdb596ceb4b7 ("smb: client: fix potential UAF in smb2_close_cached_fid()") was an incomplete backport and missed one kref_put() call in cfids_invalidation_worker() that should have been converted to close_cached_dir(). Fixes: cb52d9c86d70 ("smb: client: fix potential UAF in smb2_close_cached_fid()")" Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-12-01cifs: fix typo in enable_gcm_256 module parameterSteve French1-1/+1
[ Upstream commit f765fdfcd8b5bce92c6aa1a517ff549529ddf590 ] Fix typo in description of enable_gcm_256 module parameter Suggested-by: Thomas Spear <speeddymon@gmail.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-12-01cifs: fix memory leak in smb3_fs_context_parse_param error pathShaurya Rane1-0/+4
[ Upstream commit 7e4d9120cfa413dd34f4f434befc5dbe6c38b2e5 ] Add proper cleanup of ctx->source and fc->source to the cifs_parse_mount_err error handler. This ensures that memory allocated for the source strings is correctly freed on all error paths, matching the cleanup already performed in the success path by smb3_cleanup_fs_context_contents(). Pointers are also set to NULL after freeing to prevent potential double-free issues. This change fixes a memory leak originally detected by syzbot. The leak occurred when processing Opt_source mount options if an error happened after ctx->source and fc->source were successfully allocated but before the function completed. The specific leak sequence was: 1. ctx->source = smb3_fs_context_fullpath(ctx, '/') allocates memory 2. fc->source = kstrdup(ctx->source, GFP_KERNEL) allocates more memory 3. A subsequent error jumps to cifs_parse_mount_err 4. The old error handler freed passwords but not the source strings, causing the memory to leak. This issue was not addressed by commit e8c73eb7db0a ("cifs: client: fix memory leak in smb3_fs_context_parse_param"), which only fixed leaks from repeated fsconfig() calls but not this error path. Patch updated with minor change suggested by kernel test robot Reported-by: syzbot+87be6809ed9bf6d718e3@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=87be6809ed9bf6d718e3 Fixes: 24e0a1eff9e2 ("cifs: switch to new mount api") Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Shaurya Rane <ssrane_b23@ee.vjti.ac.in> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-12-01smb: client: introduce close_cached_dir_locked()Henrique Carvalho1-3/+38
commit a9d1f38df7ecd0e21233447c9cc6fa1799eddaf3 upstream. Replace close_cached_dir() calls under cfid_list_lock with a new close_cached_dir_locked() variant that uses kref_put() instead of kref_put_lock() to avoid recursive locking when dropping references. While the existing code works if the refcount >= 2 invariant holds, this area has proven error-prone. Make deadlocks impossible and WARN on invariant violations. Cc: stable@vger.kernel.org Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-24smb: client: fix cifs_pick_channel when channel needs reconnectHenrique Carvalho1-1/+1
commit 79280191c2fd7f24899bbd640003b5389d3c109c upstream. cifs_pick_channel iterates candidate channels using cur. The reconnect-state test mistakenly used a different variable. This checked the wrong slot and would cause us to skip a healthy channel and to dispatch on one that needs reconnect, occasionally failing operations when a channel was down. Fix by replacing for the correct variable. Fixes: fc43a8ac396d ("cifs: cifs_pick_channel should try selecting active channels") Cc: stable@vger.kernel.org Reviewed-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-24cifs: client: fix memory leak in smb3_fs_context_parse_paramEdward Adam Davis1-0/+2
commit e8c73eb7db0a498cd4b22d2819e6ab1a6f506bd6 upstream. The user calls fsconfig twice, but when the program exits, free() only frees ctx->source for the second fsconfig, not the first. Regarding fc->source, there is no code in the fs context related to its memory reclamation. To fix this memory leak, release the source memory corresponding to ctx or fc before each parsing. syzbot reported: BUG: memory leak unreferenced object 0xffff888128afa360 (size 96): backtrace (crc 79c9c7ba): kstrdup+0x3c/0x80 mm/util.c:84 smb3_fs_context_parse_param+0x229b/0x36c0 fs/smb/client/fs_context.c:1444 BUG: memory leak unreferenced object 0xffff888112c7d900 (size 96): backtrace (crc 79c9c7ba): smb3_fs_context_fullpath+0x70/0x1b0 fs/smb/client/fs_context.c:629 smb3_fs_context_parse_param+0x2266/0x36c0 fs/smb/client/fs_context.c:1438 Reported-by: syzbot+72afd4c236e6bc3f4bac@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=72afd4c236e6bc3f4bac Cc: stable@vger.kernel.org Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Signed-off-by: Edward Adam Davis <eadavis@qq.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-24cifs: Fix uncached read into ITER_KVEC iteratorDavid Howells1-3/+94
If a cifs share is mounted cache=none, internal reads (such as by exec) will pass a KVEC iterator down from __cifs_readv() to cifs_send_async_read() which will then call cifs_limit_bvec_subset() upon it to limit the number of contiguous elements for RDMA purposes. This doesn't work on non-BVEC iterators, however. Fix this by extracting a KVEC iterator into a BVEC iterator in __cifs_readv() (it would be dup'd anyway it async). This caused the following warning: WARNING: CPU: 0 PID: 6290 at fs/smb/client/file.c:3549 cifs_limit_bvec_subset+0xe/0xc0 ... Call Trace: <TASK> cifs_send_async_read+0x146/0x2e0 __cifs_readv+0x207/0x2d0 __kernel_read+0xf6/0x160 search_binary_handler+0x49/0x210 exec_binprm+0x4a/0x140 bprm_execve.part.0+0xe4/0x170 do_execveat_common.isra.0+0x196/0x1c0 do_execve+0x1f/0x30 Fixes: d08089f649a0 ("cifs: Change the I/O paths to use an iterator rather than a page list") Acked-by: Bharath SM <bharathsm@microsoft.com> Tested-by: Bharath SM <bharathsm@microsoft.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: stable@kernel.org # v6.6~v6.9 Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-24cifs: stop writeback extension when change of size is detectedShyam Prasad N1-3/+15
cifs_extend_writeback can pick up a folio on an extending write which has been dirtied, but we have aclamp on the writeback to an i_size local variable, which can cause short writes, yet mark the page as clean. This can cause a data corruption. As an example, consider this scenario: 1. First write to the file happens offset 0 len 5k. 2. Writeback starts for the range (0-5k). 3. Writeback locks page 1 in cifs_writepages_begin. But does not lock page 2 yet. 4. Page 2 is now written to by the next write, which extends the file by another 5k. Page 2 and 3 are now marked dirty. 5. Now we reach cifs_extend_writeback, where we extend to include the next folio (even if it should be partially written). We will mark page 2 for writeback. 6. But after exiting cifs_extend_writeback, we will clamp the writeback to i_size, which was 5k when it started. So we write only 1k bytes in page 2. 7. We still will now mark page 2 as flushed and mark it clean. So remaining contents of page 2 will not be written to the server (hence the hole in that gap, unless that range gets overwritten). With this patch, we will make sure not extend the writeback anymore when a change in the file size is detected. This fix also changes the error handling of cifs_extend_writeback when a folio get fails. We will now stop the extension when a folio get fails. Cc: stable@kernel.org # v6.3~v6.9 Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Acked-by: David Howells <dhowells@redhat.com> Reported-by: Mark A Whiting <whitingm@opentext.com> Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-24smb: client: fix refcount leak in smb2_set_path_attrShuhao Fu1-0/+2
[ Upstream commit b540de9e3b4fab3b9e10f30714a6f5c1b2a50ec3 ] Fix refcount leak in `smb2_set_path_attr` when path conversion fails. Function `cifs_get_writable_path` returns `cfile` with its reference counter `cfile->count` increased on success. Function `smb2_compound_op` would decrease the reference counter for `cfile`, as stated in its comment. By calling `smb2_rename_path`, the reference counter of `cfile` would leak if `cifs_convert_path_to_utf16` fails in `smb2_set_path_attr`. Fixes: 8de9e86c67ba ("cifs: create a helper to find a writeable handle by path name") Acked-by: Henrique Carvalho <henrique.carvalho@suse.com> Signed-off-by: Shuhao Fu <sfual@cse.ust.hk> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-24smb: client: fix potential UAF in smb2_close_cached_fid()Henrique Carvalho1-7/+9
commit 734e99623c5b65bf2c03e35978a0b980ebc3c2f8 upstream. find_or_create_cached_dir() could grab a new reference after kref_put() had seen the refcount drop to zero but before cfid_list_lock is acquired in smb2_close_cached_fid(), leading to use-after-free. Switch to kref_put_lock() so cfid_release() is called with cfid_list_lock held, closing that gap. Fixes: ebe98f1447bb ("cifs: enable caching of directories for which a lease is held") Cc: stable@vger.kernel.org Reported-by: Jay Shin <jaeshin@redhat.com> Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-24smb: client: validate change notify buffer before copyJoshua Rogers1-2/+5
commit 4012abe8a78fbb8869634130024266eaef7081fe upstream. SMB2_change_notify called smb2_validate_iov() but ignored the return code, then kmemdup()ed using server provided OutputBufferOffset/Length. Check the return of smb2_validate_iov() and bail out on error. Discovered with help from the ZeroPath security tooling. Signed-off-by: Joshua Rogers <linux@joshua.hu> Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Cc: stable@vger.kernel.org Fixes: e3e9463414f61 ("smb3: improve SMB3 change notification support") Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-11-24smb: client: transport: avoid reconnects triggered by pending task workFiona Ebner1-1/+9
[ Upstream commit 00be6f26a2a7c671f1402d74c4d3c30a5844660a ] When io_uring is used in the same task as CIFS, there might be unnecessary reconnects, causing issues in user-space applications like QEMU with a log like: > CIFS: VFS: \\10.10.100.81 Error -512 sending data on socket to server Certain io_uring completions might be added to task_work with notify_method being TWA_SIGNAL and thus TIF_NOTIFY_SIGNAL is set for the task. In __smb_send_rqst(), signals are masked before calling smb_send_kvec(), but the masking does not apply to TIF_NOTIFY_SIGNAL. If sk_stream_wait_memory() is reached via sock_sendmsg() while TIF_NOTIFY_SIGNAL is set, signal_pending(current) will evaluate to true there, and -EINTR will be propagated all the way from sk_stream_wait_memory() to sock_sendmsg() in smb_send_kvec(). Afterwards, __smb_send_rqst() will see that not everything was written and reconnect. Signed-off-by: Fiona Ebner <f.ebner@proxmox.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-11-24smb: client: fix potential cfid UAF in smb2_query_info_compoundHenrique Carvalho1-1/+2
commit 5c76f9961c170552c1d07c830b5e145475151600 upstream. When smb2_query_info_compound() retries, a previously allocated cfid may have been freed in the first attempt. Because cfid wasn't reset on replay, later cleanup could act on a stale pointer, leading to a potential use-after-free. Reinitialize cfid to NULL under the replay label. Example trace (trimmed): refcount_t: underflow; use-after-free. WARNING: CPU: 1 PID: 11224 at ../lib/refcount.c:28 refcount_warn_saturate+0x9c/0x110 [...] RIP: 0010:refcount_warn_saturate+0x9c/0x110 [...] Call Trace: <TASK> smb2_query_info_compound+0x29c/0x5c0 [cifs f90b72658819bd21c94769b6a652029a07a7172f] ? step_into+0x10d/0x690 ? __legitimize_path+0x28/0x60 smb2_queryfs+0x6a/0xf0 [cifs f90b72658819bd21c94769b6a652029a07a7172f] smb311_queryfs+0x12d/0x140 [cifs f90b72658819bd21c94769b6a652029a07a7172f] ? kmem_cache_alloc+0x18a/0x340 ? getname_flags+0x46/0x1e0 cifs_statfs+0x9f/0x2b0 [cifs f90b72658819bd21c94769b6a652029a07a7172f] statfs_by_dentry+0x67/0x90 vfs_statfs+0x16/0xd0 user_statfs+0x54/0xa0 __do_sys_statfs+0x20/0x50 do_syscall_64+0x58/0x80 Cc: stable@kernel.org Fixes: 4f1fffa237692 ("cifs: commands that are retried should have replay flag set") Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.com> Acked-by: Shyam Prasad N <sprasad@microsoft.com> Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de> Signed-off-by: Henrique Carvalho <henrique.carvalho@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-29cifs: Fix TCP_Server_Info::credits to be signedDavid Howells1-1/+1
commit 5b2ff4873aeab972f919d5aea11c51393322bf58 upstream. Fix TCP_Server_Info::credits to be signed, just as echo_credits and oplock_credits are. This also fixes what ought to get at least a compilation warning if not an outright error in *get_credits_field() as a pointer to the unsigned server->credits field is passed back as a pointer to a signed int. Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-cifs@vger.kernel.org Cc: stable@vger.kernel.org Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Acked-by: Pavel Shilovskiy <pshilovskiy@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-23cifs: parse_dfs_referrals: prevent oob on malformed inputEugene Korenevsky1-0/+17
commit 6447b0e355562a1ff748c4a2ffb89aae7e84d2c9 upstream. Malicious SMB server can send invalid reply to FSCTL_DFS_GET_REFERRALS - reply smaller than sizeof(struct get_dfs_referral_rsp) - reply with number of referrals smaller than NumberOfReferrals in the header Processing of such replies will cause oob. Return -EINVAL error on such replies to prevent oob-s. Signed-off-by: Eugene Korenevsky <ekorenevsky@aliyun.com> Cc: stable@vger.kernel.org Suggested-by: Nathan Chancellor <nathan@kernel.org> Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-23smb: client: Fix refcount leak for cifs_sb_tlinkShuhao Fu2-6/+8
commit c2b77f42205ef485a647f62082c442c1cd69d3fc upstream. Fix three refcount inconsistency issues related to `cifs_sb_tlink`. Comments for `cifs_sb_tlink` state that `cifs_put_tlink()` needs to be called after successful calls to `cifs_sb_tlink()`. Three calls fail to update refcount accordingly, leading to possible resource leaks. Fixes: 8ceb98437946 ("CIFS: Move rename to ops struct") Fixes: 2f1afe25997f ("cifs: Use smb 2 - 3 and cifsacl mount options getacl functions") Fixes: 366ed846df60 ("cifs: Use smb 2 - 3 and cifsacl mount options setacl function") Cc: stable@vger.kernel.org Signed-off-by: Shuhao Fu <sfual@cse.ust.hk> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-10-19cifs: Query EA $LXMOD in cifs_query_path_info() for WSL reparse pointsPali Rohár1-2/+60
[ Upstream commit 057ac50638bcece64b3b436d3a61b70ed6c01a34 ] EA $LXMOD is required for WSL non-symlink reparse points. Fixes: ef86ab131d91 ("cifs: Fix querying of WSL CHR and BLK reparse points over SMB1") Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-19smb: client: fix missing timestamp updates after utime(2)Paulo Alcantara1-10/+12
[ Upstream commit b95cd1bdf5aa9221c98fc9259014b8bb8d1829d7 ] Don't reuse open handle when changing timestamps to prevent the server from disabling automatic timestamp updates as per MS-FSA 2.1.4.17. ---8<--- import os import time filename = '/mnt/foo' def print_stat(prefix): st = os.stat(filename) print(prefix, ': ', time.ctime(st.st_atime), time.ctime(st.st_ctime)) fd = os.open(filename, os.O_CREAT|os.O_TRUNC|os.O_WRONLY, 0o644) print_stat('old') os.utime(fd, None) time.sleep(2) os.write(fd, b'foo') os.close(fd) time.sleep(2) print_stat('new') ---8<--- Before patch: $ mount.cifs //srv/share /mnt -o ... $ python3 run.py old : Fri Oct 3 14:01:21 2025 Fri Oct 3 14:01:21 2025 new : Fri Oct 3 14:01:21 2025 Fri Oct 3 14:01:21 2025 After patch: $ mount.cifs //srv/share /mnt -o ... $ python3 run.py old : Fri Oct 3 17:03:34 2025 Fri Oct 3 17:03:34 2025 new : Fri Oct 3 17:03:36 2025 Fri Oct 3 17:03:36 2025 Fixes: b6f2a0f89d7e ("cifs: for compound requests, use open handle if possible") Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Cc: Frank Sorenson <sorenson@redhat.com> Reviewed-by: David Howells <dhowells@redhat.com> Cc: linux-cifs@vger.kernel.org Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-15smb: client: fix crypto buffers in non-linear memoryEnzo Matsumiya1-11/+6
[ Upstream commit 998a67b954680f26f3734040aeeed08642d49721 ] The crypto API, through the scatterlist API, expects input buffers to be in linear memory. We handle this with the cifs_sg_set_buf() helper that converts vmalloc'd memory to their corresponding pages. However, when we allocate our aead_request buffer (@creq in smb2ops.c::crypt_message()), we do so with kvzalloc(), which possibly puts aead_request->__ctx in vmalloc area. AEAD algorithm then uses ->__ctx for its private/internal data and operations, and uses sg_set_buf() for such data on a few places. This works fine as long as @creq falls into kmalloc zone (small requests) or vmalloc'd memory is still within linear range. Tasks' stacks are vmalloc'd by default (CONFIG_VMAP_STACK=y), so too many tasks will increment the base stacks' addresses to a point where virt_addr_valid(buf) will fail (BUG() in sg_set_buf()) when that happens. In practice: too many parallel reads and writes on an encrypted mount will trigger this bug. To fix this, always alloc @creq with kmalloc() instead. Also drop the @sensitive_size variable/arguments since kfree_sensitive() doesn't need it. Backtrace: [ 945.272081] ------------[ cut here ]------------ [ 945.272774] kernel BUG at include/linux/scatterlist.h:209! [ 945.273520] Oops: invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC NOPTI [ 945.274412] CPU: 7 UID: 0 PID: 56 Comm: kworker/u33:0 Kdump: loaded Not tainted 6.15.0-lku-11779-g8e9d6efccdd7-dirty #1 PREEMPT(voluntary) [ 945.275736] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.3-2-gc13ff2cd-prebuilt.qemu.org 04/01/2014 [ 945.276877] Workqueue: writeback wb_workfn (flush-cifs-2) [ 945.277457] RIP: 0010:crypto_gcm_init_common+0x1f9/0x220 [ 945.278018] Code: b0 00 00 00 48 83 c4 08 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 48 c7 c0 00 00 00 80 48 2b 05 5c 58 e5 00 e9 58 ff ff ff <0f> 0b 0f 0b 0f 0b 0f 0b 0f 0b 0f 0b 48 c7 04 24 01 00 00 00 48 8b [ 945.279992] RSP: 0018:ffffc90000a27360 EFLAGS: 00010246 [ 945.280578] RAX: 0000000000000000 RBX: ffffc90001d85060 RCX: 0000000000000030 [ 945.281376] RDX: 0000000000080000 RSI: 0000000000000000 RDI: ffffc90081d85070 [ 945.282145] RBP: ffffc90001d85010 R08: ffffc90001d85000 R09: 0000000000000000 [ 945.282898] R10: ffffc90001d85090 R11: 0000000000001000 R12: ffffc90001d85070 [ 945.283656] R13: ffff888113522948 R14: ffffc90001d85060 R15: ffffc90001d85010 [ 945.284407] FS: 0000000000000000(0000) GS:ffff8882e66cf000(0000) knlGS:0000000000000000 [ 945.285262] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 945.285884] CR2: 00007fa7ffdd31f4 CR3: 000000010540d000 CR4: 0000000000350ef0 [ 945.286683] Call Trace: [ 945.286952] <TASK> [ 945.287184] ? crypt_message+0x33f/0xad0 [cifs] [ 945.287719] crypto_gcm_encrypt+0x36/0xe0 [ 945.288152] crypt_message+0x54a/0xad0 [cifs] [ 945.288724] smb3_init_transform_rq+0x277/0x300 [cifs] [ 945.289300] smb_send_rqst+0xa3/0x160 [cifs] [ 945.289944] cifs_call_async+0x178/0x340 [cifs] [ 945.290514] ? __pfx_smb2_writev_callback+0x10/0x10 [cifs] [ 945.291177] smb2_async_writev+0x3e3/0x670 [cifs] [ 945.291759] ? find_held_lock+0x32/0x90 [ 945.292212] ? netfs_advance_write+0xf2/0x310 [ 945.292723] netfs_advance_write+0xf2/0x310 [ 945.293210] netfs_write_folio+0x346/0xcc0 [ 945.293689] ? __pfx__raw_spin_unlock_irq+0x10/0x10 [ 945.294250] netfs_writepages+0x117/0x460 [ 945.294724] do_writepages+0xbe/0x170 [ 945.295152] ? find_held_lock+0x32/0x90 [ 945.295600] ? kvm_sched_clock_read+0x11/0x20 [ 945.296103] __writeback_single_inode+0x56/0x4b0 [ 945.296643] writeback_sb_inodes+0x229/0x550 [ 945.297140] __writeback_inodes_wb+0x4c/0xe0 [ 945.297642] wb_writeback+0x2f1/0x3f0 [ 945.298069] wb_workfn+0x300/0x490 [ 945.298472] process_one_work+0x1fe/0x590 [ 945.298949] worker_thread+0x1ce/0x3c0 [ 945.299397] ? __pfx_worker_thread+0x10/0x10 [ 945.299900] kthread+0x119/0x210 [ 945.300285] ? __pfx_kthread+0x10/0x10 [ 945.300729] ret_from_fork+0x119/0x1b0 [ 945.301163] ? __pfx_kthread+0x10/0x10 [ 945.301601] ret_from_fork_asm+0x1a/0x30 [ 945.302055] </TASK> Fixes: d08089f649a0 ("cifs: Change the I/O paths to use an iterator rather than a page list") Signed-off-by: Enzo Matsumiya <ematsumiya@suse.de> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-10-02smb: client: fix wrong index reference in smb2_compound_op()Sang-Heon Jeon1-1/+1
[ Upstream commit fbe2dc6a9c7318f7263f5e4d50f6272b931c5756 ] In smb2_compound_op(), the loop that processes each command's response uses wrong indices when accessing response bufferes. This incorrect indexing leads to improper handling of command results. Also, if incorrectly computed index is greather than or equal to MAX_COMPOUND, it can cause out-of-bounds accesses. Fixes: 3681c74d342d ("smb: client: handle lack of EA support in smb2_query_path_info()") # 6.14 Reviewed-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-25smb: client: fix smbdirect_recv_io leak in smbd_negotiate() error pathStefan Metzmacher1-1/+3
[ Upstream commit daac51c7032036a0ca5f1aa419ad1b0471d1c6e0 ] During tests of another unrelated patch I was able to trigger this error: Objects remaining on __kmem_cache_shutdown() Cc: Steve French <smfrench@gmail.com> Cc: Tom Talpey <tom@talpey.com> Cc: Long Li <longli@microsoft.com> Cc: Namjae Jeon <linkinjeon@kernel.org> Cc: linux-cifs@vger.kernel.org Cc: samba-technical@lists.samba.org Fixes: f198186aa9bb ("CIFS: SMBD: Establish SMB Direct connection") Signed-off-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-19cifs: fix pagecache leak when do writepagesYang Erkun1-3/+13
After commit f3dc1bdb6b0b("cifs: Fix writeback data corruption"), the writepages for cifs will find all folio needed writepage with two phase. The first folio will be found in cifs_writepages_begin, and the latter various folios will be found in cifs_extend_writeback. All those will first get folio, and for normal case, once we set page writeback and after do really write, we should put the reference, folio found in cifs_extend_writeback do this with folio_batch_release. But the folio found in cifs_writepages_begin never get the chance do it. And every writepages call, we will leak a folio(found this problem while do xfstests over cifs, the latter show that we will leak about 600M+ every we run generic/074). echo 3 > /proc/sys/vm/drop_caches ; cat /proc/meminfo | grep file Active(file): 34092 kB Inactive(file): 176192 kB ./check generic/074 (smb v1) ... generic/074 50s ... 53s Ran: generic/074 Passed all 1 tests echo 3 > /proc/sys/vm/drop_caches ; cat /proc/meminfo | grep file Active(file): 35036 kB Inactive(file): 854708 kB Besides, the exist path seem never handle this folio correctly, fix it too with this patch. All issue does not occur in the mainline because the writepages path for CIFS was changed to netfs (commit 3ee1a1fc3981, titled "cifs: Cut over to using netfslib") as part of a major refactor. After discussing with the CIFS maintainer, we believe that this single patch is safer for the stable branch [1]. Steve said: """ David and I discussed this today and this patch is MUCH safer than backporting the later (6.10) netfs changes which would be much larger and riskier to include (and presumably could affect code outside cifs.ko as well where this patch is narrowly targeted). I am fine with this patch.from Yang for 6.6 stable """ David said: """ Backporting the massive amount of changes to netfslib, fscache, cifs, afs, 9p, ceph and nfs would kind of diminish the notion that this is a stable kernel;-). """ Fixes: f3dc1bdb6b0b ("cifs: Fix writeback data corruption") Cc: stable@kernel.org # v6.6~v6.9 Link: https://lore.kernel.org/all/20250911030120.1076413-1-yangerkun@huawei.com/ [1] Acked-by: Steve French <stfrench@microsoft.com> Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Yang Erkun <yangerkun@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-09cifs: prevent NULL pointer dereference in UTF16 conversionMakar Semyonov1-0/+3
commit 70bccd9855dae56942f2b18a08ba137bb54093a0 upstream. There can be a NULL pointer dereference bug here. NULL is passed to __cifs_sfu_make_node without checks, which passes it unchecked to cifs_strndup_to_utf16, which in turn passes it to cifs_local_to_utf16_bytes where '*from' is dereferenced, causing a crash. This patch adds a check for NULL 'src' in cifs_strndup_to_utf16 and returns NULL early to prevent dereferencing NULL pointer. Found by Linux Verification Center (linuxtesting.org) with SVACE Signed-off-by: Makar Semyonov <m.semenov@tssltd.ru> Cc: stable@vger.kernel.org Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-04smb3 client: fix return code mapping of remap_file_rangeSteve French1-0/+14
commit 0e08fa789d39aa01923e3ba144bd808291895c3c upstream. We were returning -EOPNOTSUPP for various remap_file_range cases but for some of these the copy_file_range_syscall() requires -EINVAL to be returned (e.g. where source and target file ranges overlap when source and target are the same file). This fixes xfstest generic/157 which was expecting EINVAL for that (and also e.g. for when the src offset is beyond end of file). Cc: stable@vger.kernel.org Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-04fs/smb: Fix inconsistent refcnt updateShuhao Fu1-2/+5
commit ab529e6ca1f67bcf31f3ea80c72bffde2e9e053e upstream. A possible inconsistent update of refcount was identified in `smb2_compound_op`. Such inconsistent update could lead to possible resource leaks. Why it is a possible bug: 1. In the comment section of the function, it clearly states that the reference to `cfile` should be dropped after calling this function. 2. Every control flow path would check and drop the reference to `cfile`, except the patched one. 3. Existing callers would not handle refcount update of `cfile` if -ENOMEM is returned. To fix the bug, an extra goto label "out" is added, to make sure that the cleanup logic would always be respected. As the problem is caused by the allocation failure of `vars`, the cleanup logic between label "finished" and "out" can be safely ignored. According to the definition of function `is_replayable_error`, the error code of "-ENOMEM" is not recoverable. Therefore, the replay logic also gets ignored. Signed-off-by: Shuhao Fu <sfual@cse.ust.hk> Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Cc: stable@vger.kernel.org Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-09-04smb: client: fix race with concurrent opens in rename(2)Paulo Alcantara1-0/+18
[ Upstream commit d84291fc7453df7881a970716f8256273aca5747 ] Besides sending the rename request to the server, the rename process also involves closing any deferred close, waiting for outstanding I/O to complete as well as marking all existing open handles as deleted to prevent them from deferring closes, which increases the race window for potential concurrent opens on the target file. Fix this by unhashing the dentry in advance to prevent any concurrent opens on the target. Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Reviewed-by: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-cifs@vger.kernel.org Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-09-04smb: client: fix race with concurrent opens in unlink(2)Paulo Alcantara1-2/+14
[ Upstream commit 0af1561b2d60bab2a2b00720a5c7b292ecc549ec ] According to some logs reported by customers, CIFS client might end up reporting unlinked files as existing in stat(2) due to concurrent opens racing with unlink(2). Besides sending the removal request to the server, the unlink process could involve closing any deferred close as well as marking all existing open handles as deleted to prevent them from deferring closes, which increases the race window for potential concurrent opens. Fix this by unhashing the dentry in cifs_unlink() to prevent any subsequent opens. Any open attempts, while we're still unlinking, will block on parent's i_rwsem. Reported-by: Jay Shin <jaeshin@redhat.com> Signed-off-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Reviewed-by: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-cifs@vger.kernel.org Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-28smb: client: fix netns refcount leak after net_passive changesWang Zhaolong1-6/+3
[ Upstream commit 59b33fab4ca4d7dacc03367082777627e05d0323 ] After commit 5c70eb5c593d ("net: better track kernel sockets lifetime"), kernel sockets now use net_passive reference counting. However, commit 95d2b9f693ff ("Revert "smb: client: fix TCP timers deadlock after rmmod"") restored the manual socket refcount manipulation without adapting to this new mechanism, causing a memory leak. The issue can be reproduced by[1]: 1. Creating a network namespace 2. Mounting and Unmounting CIFS within the namespace 3. Deleting the namespace Some memory leaks may appear after a period of time following step 3. unreferenced object 0xffff9951419f6b00 (size 256): comm "ip", pid 447, jiffies 4294692389 (age 14.730s) hex dump (first 32 bytes): 1b 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 80 77 c2 44 51 99 ff ff .........w.DQ... backtrace: __kmem_cache_alloc_node+0x30e/0x3d0 __kmalloc+0x52/0x120 net_alloc_generic+0x1d/0x30 copy_net_ns+0x86/0x200 create_new_namespaces+0x117/0x300 unshare_nsproxy_namespaces+0x60/0xa0 ksys_unshare+0x148/0x360 __x64_sys_unshare+0x12/0x20 do_syscall_64+0x59/0x110 entry_SYSCALL_64_after_hwframe+0x78/0xe2 ... unreferenced object 0xffff9951442e7500 (size 32): comm "mount.cifs", pid 475, jiffies 4294693782 (age 13.343s) hex dump (first 32 bytes): 40 c5 38 46 51 99 ff ff 18 01 96 42 51 99 ff ff @.8FQ......BQ... 01 00 00 00 6f 00 c5 07 6f 00 d8 07 00 00 00 00 ....o...o....... backtrace: __kmem_cache_alloc_node+0x30e/0x3d0 kmalloc_trace+0x2a/0x90 ref_tracker_alloc+0x8e/0x1d0 sk_alloc+0x18c/0x1c0 inet_create+0xf1/0x370 __sock_create+0xd7/0x1e0 generic_ip_connect+0x1d4/0x5a0 [cifs] cifs_get_tcp_session+0x5d0/0x8a0 [cifs] cifs_mount_get_session+0x47/0x1b0 [cifs] dfs_mount_share+0xfa/0xa10 [cifs] cifs_mount+0x68/0x2b0 [cifs] cifs_smb3_do_mount+0x10b/0x760 [cifs] smb3_get_tree+0x112/0x2e0 [cifs] vfs_get_tree+0x29/0xf0 path_mount+0x2d4/0xa00 __se_sys_mount+0x165/0x1d0 Root cause: When creating kernel sockets, sk_alloc() calls net_passive_inc() for sockets with sk_net_refcnt=0. The CIFS code manually converts kernel sockets to user sockets by setting sk_net_refcnt=1, but doesn't call the corresponding net_passive_dec(). This creates an imbalance in the net_passive counter, which prevents the network namespace from being destroyed when its last user reference is dropped. As a result, the entire namespace and all its associated resources remain allocated. Timeline of patches leading to this issue: - commit ef7134c7fc48 ("smb: client: Fix use-after-free of network namespace.") in v6.12 fixed the original netns UAF by manually managing socket refcounts - commit e9f2517a3e18 ("smb: client: fix TCP timers deadlock after rmmod") in v6.13 attempted to use kernel sockets but introduced TCP timer issues - commit 5c70eb5c593d ("net: better track kernel sockets lifetime") in v6.14-rc5 introduced the net_passive mechanism with sk_net_refcnt_upgrade() for proper socket conversion - commit 95d2b9f693ff ("Revert "smb: client: fix TCP timers deadlock after rmmod"") in v6.15-rc3 reverted to manual refcount management without adapting to the new net_passive changes Fix this by using sk_net_refcnt_upgrade() which properly handles the net_passive counter when converting kernel sockets to user sockets. Link: https://bugzilla.kernel.org/show_bug.cgi?id=220343 [1] Fixes: 95d2b9f693ff ("Revert "smb: client: fix TCP timers deadlock after rmmod"") Cc: stable@vger.kernel.org Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Enzo Matsumiya <ematsumiya@suse.de> Signed-off-by: Wang Zhaolong <wangzhaolong@huaweicloud.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28cifs: reset iface weights when we cannot find a candidateShyam Prasad N1-0/+9
commit 9d5eff7821f6d70f7d1b4d8a60680fba4de868a7 upstream. We now do a weighted selection of server interfaces when allocating new channels. The weights are decided based on the speed advertised. The fulfilled weight for an interface is a counter that is used to track the interface selection. It should be reset back to zero once all interfaces fulfilling their weight. In cifs_chan_update_iface, this reset logic was missing. As a result when the server interface list changes, the client may not be able to find a new candidate for other channels after all interfaces have been fulfilled. Fixes: a6d8fb54a515 ("cifs: distribute channels across interfaces based on speed") Cc: <stable@vger.kernel.org> Signed-off-by: Shyam Prasad N <sprasad@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28cifs: Fix calling CIFSFindFirst() for root path without msearchPali Rohár1-0/+10
[ Upstream commit b460249b9a1dab7a9f58483e5349d045ad6d585c ] To query root path (without msearch wildcard) it is needed to send pattern '\' instead of '' (empty string). This allows to use CIFSFindFirst() to query information about root path which is being used in followup changes. This change fixes the stat() syscall called on the root path on the mount. It is because stat() syscall uses the cifs_query_path_info() function and it can fallback to the CIFSFindFirst() usage with msearch=false. Signed-off-by: Pali Rohár <pali@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-28smb: client: don't wait for info->send_pending == 0 on errorStefan Metzmacher1-5/+5
commit 8c48e1c7520321cc87ff651e96093e2f412785fb upstream. We already called ib_drain_qp() before and that makes sure send_done() was called with IB_WC_WR_FLUSH_ERR, but didn't called atomic_dec_and_test(&sc->send_io.pending.count) So we may never reach the info->send_pending == 0 condition. Cc: Steve French <smfrench@gmail.com> Cc: Tom Talpey <tom@talpey.com> Cc: Long Li <longli@microsoft.com> Cc: linux-cifs@vger.kernel.org Cc: samba-technical@lists.samba.org Fixes: 5349ae5e05fa ("smb: client: let send_done() cleanup before calling smbd_disconnect_rdma_connection()") Signed-off-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28smb: client: let send_done() cleanup before calling ↵Stefan Metzmacher1-6/+8
smbd_disconnect_rdma_connection() commit 5349ae5e05fa37409fd48a1eb483b199c32c889b upstream. We should call ib_dma_unmap_single() and mempool_free() before calling smbd_disconnect_rdma_connection(). And smbd_disconnect_rdma_connection() needs to be the last function to call as all other state might already be gone after it returns. Cc: Steve French <smfrench@gmail.com> Cc: Tom Talpey <tom@talpey.com> Cc: Long Li <longli@microsoft.com> Cc: linux-cifs@vger.kernel.org Cc: samba-technical@lists.samba.org Fixes: f198186aa9bb ("CIFS: SMBD: Establish SMB Direct connection") Signed-off-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28smb: client: remove redundant lstrp update in negotiate protocolWang Zhaolong1-1/+0
commit e19d8dd694d261ac26adb2a26121a37c107c81ad upstream. Commit 34331d7beed7 ("smb: client: fix first command failure during re-negotiation") addressed a race condition by updating lstrp before entering negotiate state. However, this approach may have some unintended side effects. The lstrp field is documented as "when we got last response from this server", and updating it before actually receiving a server response could potentially affect other mechanisms that rely on this timestamp. For example, the SMB echo detection logic also uses lstrp as a reference point. In scenarios with frequent user operations during reconnect states, the repeated calls to cifs_negotiate_protocol() might continuously update lstrp, which could interfere with the echo detection timing. Additionally, commit 266b5d02e14f ("smb: client: fix race condition in negotiate timeout by using more precise timing") introduced a dedicated neg_start field specifically for tracking negotiate start time. This provides a more precise solution for the original race condition while preserving the intended semantics of lstrp. Since the race condition is now properly handled by the neg_start mechanism, the lstrp update in cifs_negotiate_protocol() is no longer necessary and can be safely removed. Fixes: 266b5d02e14f ("smb: client: fix race condition in negotiate timeout by using more precise timing") Cc: stable@vger.kernel.org Acked-by: Paulo Alcantara (Red Hat) <pc@manguebit.org> Signed-off-by: Wang Zhaolong <wangzhaolong@huaweicloud.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-28smb3: fix for slab out of bounds on mount to ksmbdSteve French1-1/+10
commit 7d34ec36abb84fdfb6632a0f2cbda90379ae21fc upstream. With KASAN enabled, it is possible to get a slab out of bounds during mount to ksmbd due to missing check in parse_server_interfaces() (see below): BUG: KASAN: slab-out-of-bounds in parse_server_interfaces+0x14ee/0x1880 [cifs] Read of size 4 at addr ffff8881433dba98 by task mount/9827 CPU: 5 UID: 0 PID: 9827 Comm: mount Tainted: G OE 6.16.0-rc2-kasan #2 PREEMPT(voluntary) Tainted: [O]=OOT_MODULE, [E]=UNSIGNED_MODULE Hardware name: Dell Inc. Precision Tower 3620/0MWYPT, BIOS 2.13.1 06/14/2019 Call Trace: <TASK> dump_stack_lvl+0x9f/0xf0 print_report+0xd1/0x670 __virt_addr_valid+0x22c/0x430 ? parse_server_interfaces+0x14ee/0x1880 [cifs] ? kasan_complete_mode_report_info+0x2a/0x1f0 ? parse_server_interfaces+0x14ee/0x1880 [cifs] kasan_report+0xd6/0x110 parse_server_interfaces+0x14ee/0x1880 [cifs] __asan_report_load_n_noabort+0x13/0x20 parse_server_interfaces+0x14ee/0x1880 [cifs] ? __pfx_parse_server_interfaces+0x10/0x10 [cifs] ? trace_hardirqs_on+0x51/0x60 SMB3_request_interfaces+0x1ad/0x3f0 [cifs] ? __pfx_SMB3_request_interfaces+0x10/0x10 [cifs] ? SMB2_tcon+0x23c/0x15d0 [cifs] smb3_qfs_tcon+0x173/0x2b0 [cifs] ? __pfx_smb3_qfs_tcon+0x10/0x10 [cifs] ? cifs_get_tcon+0x105d/0x2120 [cifs] ? do_raw_spin_unlock+0x5d/0x200 ? cifs_get_tcon+0x105d/0x2120 [cifs] ? __pfx_smb3_qfs_tcon+0x10/0x10 [cifs] cifs_mount_get_tcon+0x369/0xb90 [cifs] ? dfs_cache_find+0xe7/0x150 [cifs] dfs_mount_share+0x985/0x2970 [cifs] ? check_path.constprop.0+0x28/0x50 ? save_trace+0x54/0x370 ? __pfx_dfs_mount_share+0x10/0x10 [cifs] ? __lock_acquire+0xb82/0x2ba0 ? __kasan_check_write+0x18/0x20 cifs_mount+0xbc/0x9e0 [cifs] ? __pfx_cifs_mount+0x10/0x10 [cifs] ? do_raw_spin_unlock+0x5d/0x200 ? cifs_setup_cifs_sb+0x29d/0x810 [cifs] cifs_smb3_do_mount+0x263/0x1990 [cifs] Reported-by: Namjae Jeon <linkinjeon@kernel.org> Tested-by: Namjae Jeon <linkinjeon@kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2025-08-15smb: client: return an error if rdma_connect does not return within 5 secondsStefan Metzmacher1-2/+4
[ Upstream commit 03537826f77f1c829d0593d211b38b9c876c1722 ] This matches the timeout for tcp connections. Cc: Steve French <smfrench@gmail.com> Cc: Tom Talpey <tom@talpey.com> Cc: Long Li <longli@microsoft.com> Cc: linux-cifs@vger.kernel.org Cc: samba-technical@lists.samba.org Fixes: f198186aa9bb ("CIFS: SMBD: Establish SMB Direct connection") Signed-off-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
2025-08-15smb: client: let recv_done() cleanup before notifying the callers.Stefan Metzmacher1-6/+8
[ Upstream commit bdd7afc6dca5e0ebbb75583484aa6ea9e03fbb13 ] We should call put_receive_buffer() before waking up the callers. For the internal error case of response->type being unexpected, we now also call smbd_disconnect_rdma_connection() instead of not waking up the callers at all. Note that the SMBD_TRANSFER_DATA case still has problems, which will be addressed in the next commit in order to make it easier to review this one. Cc: Steve French <smfrench@gmail.com> Cc: Tom Talpey <tom@talpey.com> Cc: Long Li <longli@microsoft.com> Cc: linux-cifs@vger.kernel.org Cc: samba-technical@lists.samba.org Fixes: f198186aa9bb ("CIFS: SMBD: Establish SMB Direct connection") Signed-off-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Sasha Levin <sashal@kernel.org>
generated by cgit v1.2.3 (git 2.39.0) at 2026-05-01 17:20:44 +0300