linux-stable.git/fs, branch v6.6.144 Linux kernel stable tree ksmbd: fix out-of-bounds read in smb_check_perm_dacl() 2026-07-04T11:42:27+00:00 Hem Parekh hemparekh1596@gmail.com 2026-06-02T23:56:46+00:00 36599894fa8536fefdf1e296c0af71b8b7226859 commit 1ef06004ed4bd6d3ed8c840d9d1a376b66d4935b upstream. The permission-check ACE walk in smb_check_perm_dacl() validates the ACE header size and caps sid.num_subauth at SID_MAX_SUB_AUTHORITIES, but it never checks that ace->size is actually large enough to contain num_subauth sub-authorities before compare_sids() dereferences them. CIFS_SID_BASE_SIZE covers the SID header up to but excluding the sub_auth[] array, and offsetof(struct smb_ace, sid) is the ACE header, so the existing guards only guarantee the 8-byte SID base, i.e. zero sub-authorities. compare_sids() then reads ace->sid.sub_auth[i] for i < min(local_sid->num_subauth, ace->sid.num_subauth). The local comparison SIDs (sid_everyone, sid_unix_NFS_mode, and the id_to_sid() result) always have at least one sub-authority, and an attacker controls the ACE revision and authority bytes (which lie within the in-bounds SID base), so they can match one of those SIDs and force the sub_auth read. A crafted ACE with size == 16 and num_subauth >= 1 placed at the tail of the security descriptor therefore causes a heap out-of-bounds read of up to SID_MAX_SUB_AUTHORITIES * sizeof(__le32) bytes past the pntsd allocation. The security descriptor is loaded by ksmbd_vfs_get_sd_xattr() into a buffer sized exactly to the on-disk data (kzalloc(sd_size) in ndr_decode_v4_ntacl()), so the read lands past the allocation. The malformed descriptor can be stored verbatim via SMB2_SET_INFO (the DACL is not normalised before being written to the security.NTACL xattr) and the read fires on a subsequent SMB2_CREATE access check, making this reachable by an authenticated client on a share that uses ACL xattrs. Add the missing num_subauth-versus-ace_size check, mirroring the identical guards already present in the sibling parsers parse_dacl() and smb_inherit_dacl(). Fixes: d07b26f39246 ("ksmbd: require minimum ACE size in smb_check_perm_dacl()") Cc: stable@vger.kernel.org Signed-off-by: Hem Parekh <hemparekh1596@gmail.com> Acked-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 1ef06004ed4bd6d3ed8c840d9d1a376b66d4935b upstream.

The permission-check ACE walk in smb_check_perm_dacl() validates the ACE
header size and caps sid.num_subauth at SID_MAX_SUB_AUTHORITIES, but it
never checks that ace->size is actually large enough to contain
num_subauth sub-authorities before compare_sids() dereferences them.

CIFS_SID_BASE_SIZE covers the SID header up to but excluding the
sub_auth[] array, and offsetof(struct smb_ace, sid) is the ACE header,
so the existing guards only guarantee the 8-byte SID base, i.e. zero
sub-authorities. compare_sids() then reads ace->sid.sub_auth[i] for
i < min(local_sid->num_subauth, ace->sid.num_subauth). The local
comparison SIDs (sid_everyone, sid_unix_NFS_mode, and the id_to_sid()
result) always have at least one sub-authority, and an attacker controls
the ACE revision and authority bytes (which lie within the in-bounds SID
base), so they can match one of those SIDs and force the sub_auth read.

A crafted ACE with size == 16 and num_subauth >= 1 placed at the tail of
the security descriptor therefore causes a heap out-of-bounds read of up
to SID_MAX_SUB_AUTHORITIES * sizeof(__le32) bytes past the pntsd
allocation. The security descriptor is loaded by ksmbd_vfs_get_sd_xattr()
into a buffer sized exactly to the on-disk data (kzalloc(sd_size) in
ndr_decode_v4_ntacl()), so the read lands past the allocation. The
malformed descriptor can be stored verbatim via SMB2_SET_INFO (the DACL
is not normalised before being written to the security.NTACL xattr) and
the read fires on a subsequent SMB2_CREATE access check, making this
reachable by an authenticated client on a share that uses ACL xattrs.

Add the missing num_subauth-versus-ace_size check, mirroring the
identical guards already present in the sibling parsers parse_dacl() and
smb_inherit_dacl().

Fixes: d07b26f39246 ("ksmbd: require minimum ACE size in smb_check_perm_dacl()")
Cc: stable@vger.kernel.org
Signed-off-by: Hem Parekh <hemparekh1596@gmail.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
NFS: Prevent resource leak in nfs_alloc_server() 2026-07-04T11:42:27+00:00 Markus Elfring elfring@users.sourceforge.net 2026-06-14T07:56:35+00:00 2ef8f2a5695ae129ba55003bdf079763c43bffb7 commit d189f224308c8ac3feeea8e442c99922bd18f1b2 upstream. It was overlooked to call ida_free() after a failed nfs_alloc_iostats() call. Thus add the missed function call in an if branch. Fixes: 1c7251187dc067a6d460cf33ca67da9c1dd87807 ("NFS: add superblock sysfs entries") Cc: stable@vger.kernel.org Reported-by: Christophe Jaillet <christophe.jaillet@wanadoo.fr> Closes: https://lore.kernel.org/linux-nfs/1c8e10c9-def7-4f0d-8aa1-23c8035a38c8@wanadoo.fr/ Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Signed-off-by: Anna Schumaker <anna.schumaker@hammerspace.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d189f224308c8ac3feeea8e442c99922bd18f1b2 upstream.

It was overlooked to call ida_free() after a failed nfs_alloc_iostats() call.
Thus add the missed function call in an if branch.

Fixes: 1c7251187dc067a6d460cf33ca67da9c1dd87807 ("NFS: add superblock sysfs entries")
Cc: stable@vger.kernel.org
Reported-by: Christophe Jaillet <christophe.jaillet@wanadoo.fr>
Closes: https://lore.kernel.org/linux-nfs/1c8e10c9-def7-4f0d-8aa1-23c8035a38c8@wanadoo.fr/
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Anna Schumaker <anna.schumaker@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
NFSv4/pNFS: reject zero-length r_addr in nfs4_decode_mp_ds_addr 2026-07-04T11:42:27+00:00 Michael Bommarito michael.bommarito@gmail.com 2026-05-27T16:30:35+00:00 6c344fff2feff9d4d716d8e4ad40e9b5040ee5ea commit 41fe0f7b84f0cb822ae10ab08592996a592b2a25 upstream. nfs4_decode_mp_ds_addr() decodes the r_netid and r_addr opaques of a netaddr4 from a GETDEVICEINFO multipath-DS body, then immediately calls strrchr(buf, '.') to locate the port separator. Both decodes use xdr_stream_decode_string_dup(), and the current code checks only "nlen < 0" / "rlen < 0" before dereferencing the returned string. When the on-wire opaque has length zero, xdr_stream_decode_opaque_inline() returns 0 and xdr_stream_decode_string_dup() falls through to its "*str = NULL; return ret" tail, leaving buf NULL with a return value of 0. The "< 0" check does not catch this, and the next line is strrchr(NULL, '.'), a kernel NULL pointer dereference reachable from any pNFS-flexfile client mounted against a malicious or compromised metadata server. Reject the zero-length cases explicitly so the decoder fails with -EBADMSG (treated as a malformed GETDEVICEINFO body) instead of panicking the client. Cc: stable@vger.kernel.org Fixes: 6b7f3cf96364 ("nfs41: pull decode_ds_addr from file layout to generic pnfs") Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com> Signed-off-by: Anna Schumaker <anna.schumaker@hammerspace.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 41fe0f7b84f0cb822ae10ab08592996a592b2a25 upstream.

nfs4_decode_mp_ds_addr() decodes the r_netid and r_addr opaques of a
netaddr4 from a GETDEVICEINFO multipath-DS body, then immediately
calls strrchr(buf, '.') to locate the port separator. Both decodes
use xdr_stream_decode_string_dup(), and the current code checks only
"nlen < 0" / "rlen < 0" before dereferencing the returned string.

When the on-wire opaque has length zero, xdr_stream_decode_opaque_inline()
returns 0 and xdr_stream_decode_string_dup() falls through to its
"*str = NULL; return ret" tail, leaving buf NULL with a return value
of 0. The "< 0" check does not catch this, and the next line is
strrchr(NULL, '.'), a kernel NULL pointer dereference reachable from
any pNFS-flexfile client mounted against a malicious or compromised
metadata server.

Reject the zero-length cases explicitly so the decoder fails with
-EBADMSG (treated as a malformed GETDEVICEINFO body) instead of
panicking the client.

Cc: stable@vger.kernel.org
Fixes: 6b7f3cf96364 ("nfs41: pull decode_ds_addr from file layout to generic pnfs")
Assisted-by: Claude:claude-opus-4-7
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Signed-off-by: Anna Schumaker <anna.schumaker@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
nfsd: check get_user() return when reading princhashlen 2026-07-04T11:42:27+00:00 Dominik Woźniak stalion@gmail.com 2026-05-21T15:46:56+00:00 abc978daffd26e62f64ed494164db0eae8b3e7fa commit e186fa1c057f5eccb22afb1e83e34c0627085868 upstream. In __cld_pipe_inprogress_downcall(), the get_user() that reads princhashlen from the userspace cld_msg_v2 buffer does not check its return value. A failing copy leaves princhashlen with uninitialised stack contents, which are then used to drive memdup_user() and stored as princhash.len on the resulting reclaim record. The other get_user() calls in this function all check the return; only this one is missed, which is most likely a copy-paste oversight from when v2 upcalls were introduced. Mirror the existing pattern used a few lines above for namelen. namecopy is declared with __free(kfree) so the early return cleans up the already-allocated buffer automatically. Fixes: 6ee95d1c8991 ("nfsd: add support for upcall version 2") Cc: stable@vger.kernel.org Signed-off-by: Dominik Woźniak <stalion@gmail.com> Reviewed-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit e186fa1c057f5eccb22afb1e83e34c0627085868 upstream.

In __cld_pipe_inprogress_downcall(), the get_user() that reads
princhashlen from the userspace cld_msg_v2 buffer does not check its
return value. A failing copy leaves princhashlen with uninitialised
stack contents, which are then used to drive memdup_user() and stored
as princhash.len on the resulting reclaim record. The other get_user()
calls in this function all check the return; only this one is missed,
which is most likely a copy-paste oversight from when v2 upcalls were
introduced.

Mirror the existing pattern used a few lines above for namelen.
namecopy is declared with __free(kfree) so the early return cleans up
the already-allocated buffer automatically.

Fixes: 6ee95d1c8991 ("nfsd: add support for upcall version 2")
Cc: stable@vger.kernel.org
Signed-off-by: Dominik Woźniak <stalion@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
nfsd: fix posix_acl leak on SETACL decode failure 2026-07-04T11:42:27+00:00 Jeff Layton jlayton@kernel.org 2026-05-21T17:51:43+00:00 1e96239fddcefacf6afe6c498357be68eacbcabc commit 0853ac544c590880d797b04daa33fcb72b6be0e1 upstream. nfsaclsvc_decode_setaclargs() and nfs3svc_decode_setaclargs() each call nfs_stream_decode_acl() twice, first for NFS_ACL and then for NFS_DFACL. Each successful call transfers ownership of a freshly allocated posix_acl into argp->acl_access or argp->acl_default. If the first call succeeds but the second fails, the decoder returns false and argp->acl_access is left dangling. ACLPROC2_SETACL.pc_release was wired to nfssvc_release_attrstat and ACLPROC3_SETACL.pc_release was wired to nfs3svc_release_fhandle. Both only call fh_put() and have no knowledge of the ACL fields on argp. The posix_acl_release() pairs sat at the out: labels inside nfsacld_proc_setacl() and nfsd3_proc_setacl(), but svc_process() skips pc_func when pc_decode returns false, so that cleanup is unreachable on decode failure: svc_process_common() pc_decode() /* decode_setaclargs: false */ /* pc_func skipped */ pc_release() /* fh_put only -- ACLs leaked */ The orphaned posix_acl is leaked for the lifetime of the server. Fix by adding nfsaclsvc_release_setacl() and nfs3svc_release_setacl(), which release both argp->acl_access and argp->acl_default in addition to fh_put(), and wiring them as pc_release for their respective SETACL procedures. pc_release runs on every path svc_process() takes after decode, including decode failure, so the posix_acl_release() pairs are removed from the proc functions' out: labels to keep ownership in one place. This matches the existing release_getacl() pattern used by the sibling GETACL procedures. Fixes: a257cdd0e217 ("[PATCH] NFSD: Add server support for NFSv3 ACLs.") Cc: stable@vger.kernel.org Assisted-by: kres:claude-opus-4-7 Signed-off-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 0853ac544c590880d797b04daa33fcb72b6be0e1 upstream.

nfsaclsvc_decode_setaclargs() and nfs3svc_decode_setaclargs() each
call nfs_stream_decode_acl() twice, first for NFS_ACL and then for
NFS_DFACL.  Each successful call transfers ownership of a freshly
allocated posix_acl into argp->acl_access or argp->acl_default.  If
the first call succeeds but the second fails, the decoder returns
false and argp->acl_access is left dangling.

ACLPROC2_SETACL.pc_release was wired to nfssvc_release_attrstat and
ACLPROC3_SETACL.pc_release was wired to nfs3svc_release_fhandle.
Both only call fh_put() and have no knowledge of the ACL fields on
argp.  The posix_acl_release() pairs sat at the out: labels inside
nfsacld_proc_setacl() and nfsd3_proc_setacl(), but svc_process()
skips pc_func when pc_decode returns false, so that cleanup is
unreachable on decode failure:

    svc_process_common()
      pc_decode()                  /* decode_setaclargs: false */
      /* pc_func skipped */
      pc_release()                 /* fh_put only -- ACLs leaked */

The orphaned posix_acl is leaked for the lifetime of the server.

Fix by adding nfsaclsvc_release_setacl() and nfs3svc_release_setacl(),
which release both argp->acl_access and argp->acl_default in addition
to fh_put(), and wiring them as pc_release for their respective SETACL
procedures.  pc_release runs on every path svc_process() takes after
decode, including decode failure, so the posix_acl_release() pairs are
removed from the proc functions' out: labels to keep ownership in one
place.  This matches the existing release_getacl() pattern used by
the sibling GETACL procedures.

Fixes: a257cdd0e217 ("[PATCH] NFSD: Add server support for NFSv3 ACLs.")
Cc: stable@vger.kernel.org
Assisted-by: kres:claude-opus-4-7
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
NFSD: Fix SECINFO_NO_NAME decode error cleanup 2026-07-04T11:42:27+00:00 Guannan Wang wgnbuaa@gmail.com 2026-05-21T08:03:32+00:00 1e04be34cafae119e82bcaccd6d28a20f72a3647 commit 9e18e83b8846a5c3fe13fc8a464b4865d33996c6 upstream. nfsd4_decode_secinfo_no_name() currently initializes sin_exp after decoding sin_style. If the XDR stream is truncated, the decoder returns nfserr_bad_xdr before sin_exp is initialized. Since commit 3fdc54646234 ("NFSD: Reduce amount of struct nfsd4_compoundargs that needs clearing"), the inline iops array is not cleared between RPC calls. A failed SECINFO_NO_NAME decode can therefore leave sin_exp holding stale union contents from a previous operation. The error response path still invokes nfsd4_secinfo_no_name_release(), which calls exp_put() on a non-NULL sin_exp. Initialize sin_exp before the first failable decode step, matching nfsd4_decode_secinfo(). Fixes: 3fdc54646234 ("NFSD: Reduce amount of struct nfsd4_compoundargs that needs clearing") Cc: stable@vger.kernel.org Signed-off-by: Guannan Wang <wgnbuaa@gmail.com> Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9e18e83b8846a5c3fe13fc8a464b4865d33996c6 upstream.

nfsd4_decode_secinfo_no_name() currently initializes sin_exp after
decoding sin_style. If the XDR stream is truncated, the decoder returns
nfserr_bad_xdr before sin_exp is initialized.

Since commit 3fdc54646234 ("NFSD: Reduce amount of struct
nfsd4_compoundargs that needs clearing"), the inline iops array is not
cleared between RPC calls. A failed SECINFO_NO_NAME decode can therefore
leave sin_exp holding stale union contents from a previous operation.

The error response path still invokes nfsd4_secinfo_no_name_release(),
which calls exp_put() on a non-NULL sin_exp.

Initialize sin_exp before the first failable decode step, matching
nfsd4_decode_secinfo().

Fixes: 3fdc54646234 ("NFSD: Reduce amount of struct nfsd4_compoundargs that needs clearing")
Cc: stable@vger.kernel.org
Signed-off-by: Guannan Wang <wgnbuaa@gmail.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ocfs2: reject oversized group bitmap descriptors 2026-07-04T11:42:27+00:00 Zhang Cen rollkingzzc@gmail.com 2026-05-24T11:12:48+00:00 c5a125eadba05ba421c4b55e68da22b4a40d32b4 commit 9bd541e09dffff27e5bec0f9f45b0228173a5375 upstream. ocfs2_validate_gd_parent() only bounds bg_bits against the parent allocator's chain geometry. A malicious descriptor can still claim a bg_size/bg_bits pair that exceeds the bitmap bytes that physically fit in the group descriptor block, so later bitmap scans and bit updates can run past bg_bitmap. Add a physical-cap check based on ocfs2_group_bitmap_size() for the parent allocator type and reject descriptors whose bg_size or bg_bits exceed that capacity. Keep the existing chain geometry check so both the on-disk bitmap layout and the allocator metadata must agree before the descriptor is used. Validation reproduced this kernel report: KASAN use-after-free in _find_next_bit+0x7f/0xc0 Read of size 8 Call trace: dump_stack_lvl+0x66/0xa0 (?:?) print_report+0xd0/0x630 (?:?) _find_next_bit+0x7f/0xc0 (?:?) srso_alias_return_thunk+0x5/0xfbef5 (?:?) __virt_addr_valid+0x188/0x2f0 (?:?) kasan_report+0xe4/0x120 (?:?) ocfs2_find_max_contig_free_bits+0x35/0x70 (fs/ocfs2/suballoc.c:1375) ocfs2_block_group_set_bits+0x472/0x4b0 (fs/ocfs2/suballoc.c:1457) ocfs2_cluster_group_search+0x16b/0x440 (fs/ocfs2/suballoc.c:86) ocfs2_bg_discontig_fix_result+0x1ef/0x230 (fs/ocfs2/suballoc.c:1786) ocfs2_search_chain+0x8f8/0x10a0 (fs/ocfs2/suballoc.c:1886) get_page_from_freelist+0x70e/0x2370 (?:?) lock_release+0xc6/0x290 (?:?) do_raw_spin_unlock+0x9a/0x100 (?:?) kasan_unpoison+0x27/0x60 (?:?) __bfs+0x147/0x240 (?:?) get_page_from_freelist+0x83d/0x2370 (?:?) ocfs2_claim_suballoc_bits+0x38c/0xe70 (fs/ocfs2/suballoc.c:96) sched_domains_numa_masks_clear+0x70/0xd0 (?:?) check_irq_usage+0xe8/0xb70 (?:?) __ocfs2_claim_clusters+0x18d/0x4c0 (fs/ocfs2/suballoc.c:2497) check_path+0x24/0x50 (?:?) rcu_is_watching+0x20/0x50 (?:?) check_prev_add+0xfd/0xd00 (?:?) ocfs2_add_clusters_in_btree+0x17d/0x810 (fs/ocfs2/suballoc.c:?) __folio_batch_add_and_move+0x1f5/0x3d0 (?:?) ocfs2_add_inode_data+0xd9/0x120 (fs/ocfs2/suballoc.c:?) filemap_add_folio+0x105/0x1f0 (?:?) ocfs2_write_begin_nolock+0x29f7/0x2f80 (fs/ocfs2/suballoc.c:3043) ocfs2_read_inode_block+0xb5/0x110 (fs/ocfs2/suballoc.c:?) down_write+0xf5/0x180 (?:?) ocfs2_write_begin+0x180/0x240 (fs/ocfs2/suballoc.c:?) __mark_inode_dirty+0x758/0x9a0 (?:?) inode_to_bdi+0x41/0x90 (?:?) balance_dirty_pages_ratelimited_flags+0xf8/0x1d0 (?:?) generic_perform_write+0x252/0x440 (?:?) mnt_put_write_access_file+0x16/0x70 (?:?) file_update_time_flags+0xe4/0x200 (?:?) ocfs2_file_write_iter+0x80a/0x1320 (fs/ocfs2/suballoc.c:?) lock_acquire+0x184/0x2f0 (?:?) ksys_write+0xd2/0x170 (?:?) apparmor_file_permission+0xf5/0x310 (?:?) read_zero+0x8d/0x140 (?:?) lock_is_held_type+0x8f/0x100 (?:?) Link: https://lore.kernel.org/20260524111248.1429884-1-rollkingzzc@gmail.com Fixes: ccd979bdbce9 ("[PATCH] OCFS2: The Second Oracle Cluster Filesystem") Assisted-by: Codex:gpt-5.5 Signed-off-by: Zhang Cen <rollkingzzc@gmail.com> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Jun Piao <piaojun@huawei.com> Cc: Heming Zhao <heming.zhao@suse.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9bd541e09dffff27e5bec0f9f45b0228173a5375 upstream.

ocfs2_validate_gd_parent() only bounds bg_bits against the parent
allocator's chain geometry.  A malicious descriptor can still claim a
bg_size/bg_bits pair that exceeds the bitmap bytes that physically fit in
the group descriptor block, so later bitmap scans and bit updates can run
past bg_bitmap.

Add a physical-cap check based on ocfs2_group_bitmap_size() for the parent
allocator type and reject descriptors whose bg_size or bg_bits exceed that
capacity.  Keep the existing chain geometry check so both the on-disk
bitmap layout and the allocator metadata must agree before the descriptor
is used.

Validation reproduced this kernel report:
KASAN use-after-free in _find_next_bit+0x7f/0xc0
Read of size 8
Call trace:
  dump_stack_lvl+0x66/0xa0 (?:?)
  print_report+0xd0/0x630 (?:?)
  _find_next_bit+0x7f/0xc0 (?:?)
  srso_alias_return_thunk+0x5/0xfbef5 (?:?)
  __virt_addr_valid+0x188/0x2f0 (?:?)
  kasan_report+0xe4/0x120 (?:?)
  ocfs2_find_max_contig_free_bits+0x35/0x70 (fs/ocfs2/suballoc.c:1375)
  ocfs2_block_group_set_bits+0x472/0x4b0 (fs/ocfs2/suballoc.c:1457)
  ocfs2_cluster_group_search+0x16b/0x440 (fs/ocfs2/suballoc.c:86)
  ocfs2_bg_discontig_fix_result+0x1ef/0x230 (fs/ocfs2/suballoc.c:1786)
  ocfs2_search_chain+0x8f8/0x10a0 (fs/ocfs2/suballoc.c:1886)
  get_page_from_freelist+0x70e/0x2370 (?:?)
  lock_release+0xc6/0x290 (?:?)
  do_raw_spin_unlock+0x9a/0x100 (?:?)
  kasan_unpoison+0x27/0x60 (?:?)
  __bfs+0x147/0x240 (?:?)
  get_page_from_freelist+0x83d/0x2370 (?:?)
  ocfs2_claim_suballoc_bits+0x38c/0xe70 (fs/ocfs2/suballoc.c:96)
  sched_domains_numa_masks_clear+0x70/0xd0 (?:?)
  check_irq_usage+0xe8/0xb70 (?:?)
  __ocfs2_claim_clusters+0x18d/0x4c0 (fs/ocfs2/suballoc.c:2497)
  check_path+0x24/0x50 (?:?)
  rcu_is_watching+0x20/0x50 (?:?)
  check_prev_add+0xfd/0xd00 (?:?)
  ocfs2_add_clusters_in_btree+0x17d/0x810 (fs/ocfs2/suballoc.c:?)
  __folio_batch_add_and_move+0x1f5/0x3d0 (?:?)
  ocfs2_add_inode_data+0xd9/0x120 (fs/ocfs2/suballoc.c:?)
  filemap_add_folio+0x105/0x1f0 (?:?)
  ocfs2_write_begin_nolock+0x29f7/0x2f80 (fs/ocfs2/suballoc.c:3043)
  ocfs2_read_inode_block+0xb5/0x110 (fs/ocfs2/suballoc.c:?)
  down_write+0xf5/0x180 (?:?)
  ocfs2_write_begin+0x180/0x240 (fs/ocfs2/suballoc.c:?)
  __mark_inode_dirty+0x758/0x9a0 (?:?)
  inode_to_bdi+0x41/0x90 (?:?)
  balance_dirty_pages_ratelimited_flags+0xf8/0x1d0 (?:?)
  generic_perform_write+0x252/0x440 (?:?)
  mnt_put_write_access_file+0x16/0x70 (?:?)
  file_update_time_flags+0xe4/0x200 (?:?)
  ocfs2_file_write_iter+0x80a/0x1320 (fs/ocfs2/suballoc.c:?)
  lock_acquire+0x184/0x2f0 (?:?)
  ksys_write+0xd2/0x170 (?:?)
  apparmor_file_permission+0xf5/0x310 (?:?)
  read_zero+0x8d/0x140 (?:?)
  lock_is_held_type+0x8f/0x100 (?:?)

Link: https://lore.kernel.org/20260524111248.1429884-1-rollkingzzc@gmail.com
Fixes: ccd979bdbce9 ("[PATCH] OCFS2: The Second Oracle Cluster Filesystem")
Assisted-by: Codex:gpt-5.5
Signed-off-by: Zhang Cen <rollkingzzc@gmail.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Cc: Heming Zhao <heming.zhao@suse.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
pNFS: Fix use-after-free in pnfs_update_layout() 2026-07-04T11:42:26+00:00 Wentao Liang vulab@iscas.ac.cn 2026-05-18T13:10:36+00:00 7e37e9b3e82ade881e1798e2f4fcc54aff7793c1 commit 13e198a90ca4050f4bee8a3f23680389a6563ccc upstream. When hitting the NFS_LAYOUT_RETURN branch in pnfs_update_layout(), the code calls pnfs_prepare_to_retry_layoutget(lo). If it succeeds, pnfs_put_layout_hdr(lo) is called before trace_pnfs_update_layout(), which still references 'lo'. This results in a use-after-free when the tracepoint accesses lo's fields. Fix this by moving the tracepoint call before pnfs_put_layout_hdr(lo). Fixes: 2c8d5fc37fe2 ("pNFS: Stricter ordering of layoutget and layoutreturn") Cc: stable@vger.kernel.org Signed-off-by: Wentao Liang <vulab@iscas.ac.cn> Signed-off-by: Anna Schumaker <anna.schumaker@hammerspace.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 13e198a90ca4050f4bee8a3f23680389a6563ccc upstream.

When hitting the NFS_LAYOUT_RETURN branch in pnfs_update_layout(),
the code calls pnfs_prepare_to_retry_layoutget(lo). If it succeeds,
pnfs_put_layout_hdr(lo) is called before trace_pnfs_update_layout(),
which still references 'lo'. This results in a use-after-free when the
tracepoint accesses lo's fields.

Fix this by moving the tracepoint call before pnfs_put_layout_hdr(lo).

Fixes: 2c8d5fc37fe2 ("pNFS: Stricter ordering of layoutget and layoutreturn")
Cc: stable@vger.kernel.org
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
Signed-off-by: Anna Schumaker <anna.schumaker@hammerspace.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gfs2: fix use-after-free in gfs2_qd_dealloc 2026-07-04T11:42:26+00:00 Tristan Madani tristan@talencesecurity.com 2026-05-01T11:02:03+00:00 4fe388218826df8607ae41a6305df67db08a9093 commit f9c9ec2c319f843b70ecdf939d48b52d189bc081 upstream. gfs2_qd_dealloc(), called as an RCU callback from gfs2_qd_dispose(), accesses the superblock object sdp through qd->qd_sbd after freeing qd. It does so to decrement sd_quota_count and wake up sd_kill_wait. However, by the time the RCU callback runs, gfs2_put_super() may have already freed sdp via free_sbd(). This can happen when gfs2_quota_cleanup() is called during unmount: it disposes of quota objects via call_rcu() and then waits on sd_kill_wait with a 60-second timeout. If the timeout expires, or if gfs2_gl_hash_clear() triggers additional qd_put() calls that schedule more RCU callbacks after the wait completes, gfs2_put_super() will proceed to free the superblock while RCU callbacks referencing it are still pending. Add an rcu_barrier() before free_sbd() in gfs2_put_super() to ensure all pending RCU callbacks (including gfs2_qd_dealloc) have completed before the superblock is freed. Fixes: a475c5dd16e5 ("gfs2: Free quota data objects synchronously") Reported-by: syzbot+42a37bf8045847d8f9d2@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=42a37bf8045847d8f9d2 Tested-by: syzbot+42a37bf8045847d8f9d2@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Signed-off-by: Tristan Madani <tristan@talencesecurity.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f9c9ec2c319f843b70ecdf939d48b52d189bc081 upstream.

gfs2_qd_dealloc(), called as an RCU callback from gfs2_qd_dispose(),
accesses the superblock object sdp through qd->qd_sbd after freeing qd.
It does so to decrement sd_quota_count and wake up sd_kill_wait.

However, by the time the RCU callback runs, gfs2_put_super() may have
already freed sdp via free_sbd().  This can happen when
gfs2_quota_cleanup() is called during unmount: it disposes of quota
objects via call_rcu() and then waits on sd_kill_wait with a 60-second
timeout.  If the timeout expires, or if gfs2_gl_hash_clear() triggers
additional qd_put() calls that schedule more RCU callbacks after the
wait completes, gfs2_put_super() will proceed to free the superblock
while RCU callbacks referencing it are still pending.

Add an rcu_barrier() before free_sbd() in gfs2_put_super() to ensure
all pending RCU callbacks (including gfs2_qd_dealloc) have completed
before the superblock is freed.

Fixes: a475c5dd16e5 ("gfs2: Free quota data objects synchronously")
Reported-by: syzbot+42a37bf8045847d8f9d2@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=42a37bf8045847d8f9d2
Tested-by: syzbot+42a37bf8045847d8f9d2@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Tristan Madani <tristan@talencesecurity.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
exfat: fix potential use-after-free in exfat_find_dir_entry() 2026-07-04T11:42:26+00:00 Michael Bommarito michael.bommarito@gmail.com 2026-04-22T15:58:44+00:00 8e0abc17fbd7e305802e84fe98b4950d50f9c433 commit 3f5f8ee9917cc2b9076ac533492d8a200edcabb8 upstream. In exfat_find_dir_entry(), the buffer_head obtained from exfat_get_dentry() is released with brelse(bh) before the fall-through TYPE_EXTEND branch reads the directory entry through ep (which points into bh->b_data): brelse(bh); if (entry_type == TYPE_EXTEND) { ... len = exfat_extract_uni_name(ep, entry_uniname); ... } After brelse() drops our reference, nothing guarantees that the underlying page backing bh->b_data remains valid for the subsequent exfat_extract_uni_name() read. This is the same pattern fixed in commit fc961522ddbd ("exfat: Fix potential use after free in exfat_load_upcase_table()"). Move brelse(bh) so it runs after ep is no longer dereferenced on each branch. Confirmed on QEMU x86_64 with CONFIG_KASAN=y + CONFIG_DEBUG_PAGEALLOC=y + CONFIG_PAGE_POISONING=y on linux-next, using a crafted exFAT image (long filename with same-hash collisions forcing the TYPE_EXTEND path). With a debug-only invalidate_bdev() inserted between brelse(bh) and the ep read to make the stale-deref window deterministic, the unpatched kernel faults: BUG: KASAN: use-after-free in exfat_find_dir_entry+0x133b/0x15a0 BUG: unable to handle page fault for address: ffff88801a5fa0c2 Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI RIP: 0010:exfat_find_dir_entry+0x1188/0x15a0 With this patch applied, the same instrumented harness completes cleanly under the same sanitizer stack. I have not reproduced a crash on an uninstrumented kernel under ordinary reclaim; the instrumented A/B establishes the lifetime violation and that the patch closes it, not an unaided triggerability claim. Fixes: ca06197382bd ("exfat: add directory operations") Cc: stable@vger.kernel.org Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 3f5f8ee9917cc2b9076ac533492d8a200edcabb8 upstream.

In exfat_find_dir_entry(), the buffer_head obtained from
exfat_get_dentry() is released with brelse(bh) before the fall-through
TYPE_EXTEND branch reads the directory entry through ep (which points
into bh->b_data):

	brelse(bh);
	if (entry_type == TYPE_EXTEND) {
		...
		len = exfat_extract_uni_name(ep, entry_uniname);
		...
	}

After brelse() drops our reference, nothing guarantees that the
underlying page backing bh->b_data remains valid for the subsequent
exfat_extract_uni_name() read. This is the same pattern fixed in
commit fc961522ddbd ("exfat: Fix potential use after free in
exfat_load_upcase_table()").

Move brelse(bh) so it runs after ep is no longer dereferenced on
each branch.

Confirmed on QEMU x86_64 with CONFIG_KASAN=y + CONFIG_DEBUG_PAGEALLOC=y
+ CONFIG_PAGE_POISONING=y on linux-next, using a crafted exFAT image
(long filename with same-hash collisions forcing the TYPE_EXTEND path).
With a debug-only invalidate_bdev() inserted between brelse(bh) and
the ep read to make the stale-deref window deterministic, the
unpatched kernel faults:

  BUG: KASAN: use-after-free in exfat_find_dir_entry+0x133b/0x15a0
  BUG: unable to handle page fault for address: ffff88801a5fa0c2
  Oops: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN NOPTI
  RIP: 0010:exfat_find_dir_entry+0x1188/0x15a0

With this patch applied, the same instrumented harness completes
cleanly under the same sanitizer stack. I have not reproduced a
crash on an uninstrumented kernel under ordinary reclaim; the
instrumented A/B establishes the lifetime violation and that the
patch closes it, not an unaided triggerability claim.

Fixes: ca06197382bd ("exfat: add directory operations")
Cc: stable@vger.kernel.org
Assisted-by: Claude:claude-opus-4-7
Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>