linux-stable.git/fs, branch v6.18.44 Linux kernel stable tree fs/proc/task_mmu: fix PAGEMAP_SCAN written state for unpopulated ptes 2026-08-09T18:25:26+00:00 Kiryl Shutsemau (Meta) kas@kernel.org 2026-08-05T13:43:52+00:00 be11b4bf498a38671743da800cc24be9f43b17b7 [ Upstream commit 07b4377bdbe74a3ec0c8da5849d014f70e003384 ] 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> (cherry picked from commit 07b4377bdbe74a3ec0c8da5849d014f70e003384) [ kas: fix only; selftest hunk dropped (pagemap_ioctl.c differs on this tree). Add the pte_none early-return before the pte_present branch ] Signed-off-by: Kiryl Shutsemau (Meta) <kas@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 07b4377bdbe74a3ec0c8da5849d014f70e003384 ]

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>
(cherry picked from commit 07b4377bdbe74a3ec0c8da5849d014f70e003384)
[ kas: fix only; selftest hunk dropped (pagemap_ioctl.c differs on this tree). Add the pte_none early-return before the pte_present branch ]

Signed-off-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
cifs: add fscache_resize_cookie() to cifs_setsize() 2026-08-09T18:25:18+00:00 Frank Sorenson sorenson@redhat.com 2026-07-25T21:04:44+00:00 efbcecdecefc26fa062c0e8210533ccad7d6bd4a 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> 
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>
binfmt_misc: don't let an 'F' entry pin its own instance 2026-08-09T18:25:16+00:00 Christian Brauner brauner@kernel.org 2026-07-28T12:26:32+00:00 4dad8ca637d44d5a6d5c23fa80c9e2e455198c2b 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> 
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>
binfmt_misc: reject a flag character as the field delimiter 2026-08-09T18:25:16+00:00 Christian Brauner brauner@kernel.org 2026-07-10T09:33:04+00:00 840bb9c49c3e75fb32b593d67ab32f6b77122262 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> 
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>
binfmt_misc: use exe_file_deny_write_access() for the interpreter clone 2026-08-09T18:25:16+00:00 Christian Brauner brauner@kernel.org 2026-07-10T09:33:03+00:00 255a758697da87a205e072e0cfc35897b8f743b1 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> 
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>
binfmt_misc: restore write access when removing an entry 2026-08-09T18:25:16+00:00 Christian Brauner brauner@kernel.org 2026-07-10T09:33:02+00:00 fdc1d702bf3001586221fa07e598e876a0a854c5 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> 
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>
ksmbd: reject repeated SMB2 NEGOTIATE requests 2026-08-09T18:25:15+00:00 Namjae Jeon linkinjeon@kernel.org 2026-07-23T14:07:14+00:00 a60b5da05e318d9a364dbac38c347c7f24e625e7 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> 
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>
afs: Fix UAF when sending a message 2026-08-09T18:25:13+00:00 David Howells dhowells@redhat.com 2026-07-23T11:34:48+00:00 c0d3b81f703b2a9e37fe1347610a50cdf0078c27 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> 
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>
afs: Fix afs_fs_fetch_data() to subtract transferred from len 2026-08-09T18:25:13+00:00 David Howells dhowells@redhat.com 2026-07-23T11:34:47+00:00 d703f022a28a27c9431c1ad7958216709e253365 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> 
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>
afs: Fix afs_fs_fetch_data() to set call->async 2026-08-09T18:25:13+00:00 David Howells dhowells@redhat.com 2026-07-23T11:34:46+00:00 b53face003b4d790fa5c4ff746134e738f115150 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> 
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>