kernel/linux.git/fs, branch v6.12.93

mm: perform all memfd seal checks in a single place

2026-06-09T10:26:05+00:00

[ Upstream commit fa00b8ef1803fe133b4897c25227aa0d298dd093 ] We no longer actually need to perform these checks in the f_op->mmap() hook any longer. We already moved the operation which clears VM_MAYWRITE on a read-only mapping of a write-sealed memfd in order to work around the restrictions imposed by commit 5de195060b2e ("mm: resolve faulty mmap_region() error path behaviour"). There is no reason for us not to simply go ahead and additionally check to see if any pre-existing seals are in place here rather than defer this to the f_op->mmap() hook. By doing this we remove more logic from shmem_mmap() which doesn't belong there, as well as doing the same for hugetlbfs_file_mmap(). We also remove dubious shared logic in mm.h which simply does not belong there either. It makes sense to do these checks at the earliest opportunity, we know these are shmem (or hugetlbfs) mappings whose relevant VMA flags will not change from the invoking do_mmap() so there is simply no need to wait. This also means the implementation of further memfd seal flags can be done within mm/memfd.c and also have the opportunity to modify VMA flags as necessary early in the mapping logic. [lorenzo.stoakes@oracle.com: fix typos in !memfd inline stub] Link: https://lkml.kernel.org/r/7dee6c5d-480b-4c24-b98e-6fa47dbd8a23@lucifer.local Link: https://lkml.kernel.org/r/20241206212846.210835-1-lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes Tested-by: Isaac J. Manjarres Cc: Hugh Dickins Cc: Jann Horn Cc: Kalesh Singh Cc: Liam R. Howlett Cc: Muchun Song Cc: Vlastimil Babka Cc: Jeff Xu Signed-off-by: Andrew Morton Stable-dep-of: 3b041514cb6e ("memfd: deny writeable mappings when implying SEAL_WRITE") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

ksmbd: OOB read regression in smb_check_perm_dacl() ACE-walk loops

2026-06-09T10:25:56+00:00

commit 0e60dafe97eca61721f3db456f97d97a80c6c8ae upstream. Commit d07b26f39246 ("ksmbd: require minimum ACE size in smb_check_perm_dacl()") introduced a transposed bounds check: if (offsetof(struct smb_ace, sid) + aces_size < CIFS_SID_BASE_SIZE) Since offsetof(..sid) is 8 and CIFS_SID_BASE_SIZE is 8, this evaluates to `aces_size < 0`. Because `aces_size` is always non-negative, this check becomes dead code and never breaks the loop. Worse, that commit removed the old 4-byte guard, meaning the loop now reads `ace->size` (offset 2) even when `aces_size` is 0-3 bytes. This re-opens a 2-byte heap out-of-bounds (OOB) read past the pntsd allocation during subsequent SMB2_CREATE operations. Fix this by properly transposing the comparison to require at least 16 bytes (8-byte offset + 8-byte SID base), matching the correct form used in smb_inherit_dacl(). Fixes: d07b26f39246 ("ksmbd: require minimum ACE size in smb_check_perm_dacl()") Cc: stable@vger.kernel.org Signed-off-by: Ali Ganiyev Acked-by: Namjae Jeon Signed-off-by: Steve French Signed-off-by: Greg Kroah-Hartman

hpfs: fix a crash if hpfs_map_dnode_bitmap fails

2026-06-09T10:25:49+00:00

commit 974820a59efde7c1a7e1260bcfe9bb81f833cc9f upstream. If hpfs_map_dnode_bitmap fails, the code would call hpfs_brelse4 on uninitialized quad buffer head, causing a crash. Signed-off-by: Mikulas Patocka Reported-by: Farhad Alemi Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman

remove pointless includes of

2026-06-09T10:25:43+00:00

[ Upstream commit be5498cac2ddb112c5bd7433d5e834a1a2493427 ] some of those used to be needed, some had been cargo-culted for no reason... Reviewed-by: Christian Brauner Signed-off-by: Al Viro Stable-dep-of: ea5fe6a73ca5 ("net/handshake: Drain pending requests at net namespace exit") Signed-off-by: Sasha Levin

btrfs: fix squota accounting during enable generation

2026-06-01T15:46:30+00:00

[ Upstream commit d7c600554816b8ef70adffe078a0e360c055d82b ] The first transaction that enables squotas is special and a bit tricky. We have to set BTRFS_FS_QUOTA_ENABLED after the transaction to avoid a deadlock, so any delayed refs that run before we set the bit are not squota accounted. For data this is fine, we don't get an owner_ref, so there is no real harm, it's as if the extent predated squotas. However for metadata, the tree block will have gen == enable_gen so when we free it later, we will decrement the squota accounting, which can result in an underflow. Before it is freed, btrfs check shows errors, as we have mismatched usage between the node generations/owners and the squota values. There are two angles to this fix: 1. For extents that come in delayed_refs that run during the enable_gen transaction, we must actually set enable_gen to the *next* transaction. That is the first transaction that we can really properly account in any way. 2. For extents that come in between the end of our transaction handle and the time we set the BTRFS_FS_QUOTA_ENABLED bit, we need an additional bit, BTRFS_FS_SQUOTA_ENABLING which only affects recording squota deltas, so we do pick up those extents. Otherwise, we would miss them, even for enable_gen + 1. Fixes: bd7c1ea3a302 ("btrfs: qgroup: check generation when recording simple quota delta") Reviewed-by: Qu Wenruo Signed-off-by: Boris Burkov Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Sasha Levin

netfs: Fix folio->private handling in netfs_perform_write()

2026-06-01T15:46:27+00:00

[ Upstream commit ccde2ac757c713535b224233a296de40efe5212d ] Under some circumstances, netfs_perform_write() doesn't correctly manipulate folio->private between NULL, NETFS_FOLIO_COPY_TO_CACHE, pointing to a group and pointing to a netfs_folio struct, leading to potential multiple attachments of private data with associated folio ref leaks and also leaks of netfs_folio structs or netfs_group refs. Fix this by consolidating the place at which a folio is marked uptodate in one place and having that look at what's attached to folio->private and decide how to clean it up and then set the new group. Also, the content shouldn't be flushed if group is NULL, even if a group is specified in the netfs_group parameter, as that would be the case for a new folio. A filesystem should always specify netfs_group or never specify netfs_group. The Sashiko auto-review tool noted that it was theoretically possible that the fpos >= ctx->zero_point section might leak if it modified a streaming write folio. This is unlikely, but with a network filesystem, third party changes can happen. It also pointed out that __netfs_set_group() would leak if called multiple times on the same folio from the "whole folio modify section". Fixes: 8f52de0077ba ("netfs: Reduce number of conditional branches in netfs_perform_write()") Closes: https://sashiko.dev/#/patchset/20260414082004.3756080-1-dhowells%40redhat.com Signed-off-by: David Howells Link: https://patch.msgid.link/20260512123404.719402-22-dhowells@redhat.com cc: Paulo Alcantara cc: Matthew Wilcox cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin

netfs: Remove unnecessary references to pages

2026-06-01T15:46:27+00:00

[ Upstream commit e995e8b600260cff3cfaf2607a62be8bdc4aa9c7 ] These places should all use folios instead of pages. Signed-off-by: Matthew Wilcox (Oracle) Link: https://lore.kernel.org/r/20241005182307.3190401-4-willy@infradead.org Signed-off-by: Christian Brauner Stable-dep-of: ccde2ac757c7 ("netfs: Fix folio->private handling in netfs_perform_write()") Signed-off-by: Sasha Levin

netfs: Fix a few minor bugs in netfs_page_mkwrite()

2026-06-01T15:46:27+00:00

[ Upstream commit c6a90fe7f080d71271b723490454cfda1f81e4b0 ] We can't return with VM_FAULT_SIGBUS | VM_FAULT_LOCKED; the core code will not unlock the folio in this instance. Introduce a new "unlock" error exit to handle this case. Use it to handle the "folio is truncated" check, and change the "writeback interrupted by a fatal signal" to do a NOPAGE exit instead of letting the core code install the folio currently under writeback before killing the process. Signed-off-by: Matthew Wilcox (Oracle) Link: https://lore.kernel.org/r/20241005182307.3190401-3-willy@infradead.org Signed-off-by: Christian Brauner Stable-dep-of: ccde2ac757c7 ("netfs: Fix folio->private handling in netfs_perform_write()") Signed-off-by: Sasha Levin

netfs: Fix partial invalidation of streaming-write folio

2026-06-01T15:46:27+00:00

[ Upstream commit 6d91acc7fb85d33ea58fca9b964a32a453937f4b ] In netfs_invalidate_folio(), if the region of a partial invalidation overlaps the front (but not all) of a dirty write cached in a streaming write page (dirty, but not uptodate, with the dirty region tracked by a netfs_folio struct), the function modifies the dirty region - but incorrectly as it moves the region forward by setting the start to the start, not the end, of the invalidation region. Fix this by setting finfo->dirty_offset to the end of the invalidation region (iend). Fixes: cce6bfa6ca0e ("netfs: Fix trimming of streaming-write folios in netfs_inval_folio()") Closes: https://sashiko.dev/#/patchset/20260414082004.3756080-1-dhowells%40redhat.com Signed-off-by: David Howells Link: https://patch.msgid.link/20260512123404.719402-21-dhowells@redhat.com cc: Paulo Alcantara cc: Matthew Wilcox cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin

netfs: Fix early put of sink folio in netfs_read_gaps()

2026-06-01T15:46:27+00:00

[ Upstream commit 3e5dd91b87a8b1450217b56a336bee315f40da7d ] Fix netfs_read_gaps() to release the sink page it uses after waiting for the request to complete. The way the sink page is used is that an ITER_BVEC-class iterator is created that has the gaps from the target folio at either end, but has the sink page tiled over the middle so that a single read op can fill in both gaps. The bug was found by KASAN detecting a UAF on the generic/075 xfstest in the cifsd kernel thread that handles reception of data from the TCP socket: BUG: KASAN: use-after-free in _copy_to_iter+0x48a/0xa20 Write of size 885 at addr ffff888107f92000 by task cifsd/1285 CPU: 2 UID: 0 PID: 1285 Comm: cifsd Not tainted 7.0.0 #6 PREEMPT(lazy) Call Trace: dump_stack_lvl+0x5d/0x80 print_report+0x17f/0x4f1 kasan_report+0x100/0x1e0 kasan_check_range+0x10f/0x1e0 __asan_memcpy+0x3c/0x60 _copy_to_iter+0x48a/0xa20 __skb_datagram_iter+0x2c9/0x430 skb_copy_datagram_iter+0x6e/0x160 tcp_recvmsg_locked+0xce0/0x1130 tcp_recvmsg+0xeb/0x300 inet_recvmsg+0xcf/0x3a0 sock_recvmsg+0xea/0x100 cifs_readv_from_socket+0x3a6/0x4d0 [cifs] cifs_read_iter_from_socket+0xdd/0x130 [cifs] cifs_readv_receive+0xaad/0xb10 [cifs] cifs_demultiplex_thread+0x1148/0x1740 [cifs] kthread+0x1cf/0x210 Fixes: ee4cdf7ba857 ("netfs: Speed up buffered reading") Reported-by: Steve French Signed-off-by: David Howells Link: https://patch.msgid.link/20260512123404.719402-18-dhowells@redhat.com Reviewed-by: Paulo Alcantara (Red Hat) cc: Paulo Alcantara cc: Matthew Wilcox cc: netfs@lists.linux.dev cc: linux-fsdevel@vger.kernel.org Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin