linux-stable.git/fs, branch linux-6.19.y

nilfs2: fix NULL i_assoc_inode dereference in nilfs_mdt_save_to_shadow_map

2026-04-22T11:30:52+00:00

commit 4a4e0328edd9e9755843787d28f16dd4165f8b48 upstream.

The DAT inode's btree node cache (i_assoc_inode) is initialized lazily
during btree operations. However, nilfs_mdt_save_to_shadow_map()
assumes i_assoc_inode is already initialized when copying dirty pages
to the shadow map during GC.

If NILFS_IOCTL_CLEAN_SEGMENTS is called immediately after mount before
any btree operation has occurred on the DAT inode, i_assoc_inode is
NULL leading to a general protection fault.

Fix this by calling nilfs_attach_btree_node_cache() on the DAT inode
in nilfs_dat_read() at mount time, ensuring i_assoc_inode is always
initialized before any GC operation can use it.

Reported-by: syzbot+4b4093b1f24ad789bf37@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=4b4093b1f24ad789bf37
Tested-by: syzbot+4b4093b1f24ad789bf37@syzkaller.appspotmail.com
Fixes: e897be17a441 ("nilfs2: fix lockdep warnings in page operations for btree nodes")
Signed-off-by: Deepanshu Kartikey 
Signed-off-by: Ryusuke Konishi 
Cc: stable@vger.kernel.org
Signed-off-by: Viacheslav Dubeyko 
Signed-off-by: Greg Kroah-Hartman

ocfs2: fix out-of-bounds write in ocfs2_write_end_inline

2026-04-22T11:30:50+00:00

[ Upstream commit 7bc5da4842bed3252d26e742213741a4d0ac1b14 ]

KASAN reports a use-after-free write of 4086 bytes in
ocfs2_write_end_inline, called from ocfs2_write_end_nolock during a
copy_file_range splice fallback on a corrupted ocfs2 filesystem mounted on
a loop device.  The actual bug is an out-of-bounds write past the inode
block buffer, not a true use-after-free.  The write overflows into an
adjacent freed page, which KASAN reports as UAF.

The root cause is that ocfs2_try_to_write_inline_data trusts the on-disk
id_count field to determine whether a write fits in inline data.  On a
corrupted filesystem, id_count can exceed the physical maximum inline data
capacity, causing writes to overflow the inode block buffer.

Call trace (crash path):

   vfs_copy_file_range (fs/read_write.c:1634)
     do_splice_direct
       splice_direct_to_actor
         iter_file_splice_write
           ocfs2_file_write_iter
             generic_perform_write
               ocfs2_write_end
                 ocfs2_write_end_nolock (fs/ocfs2/aops.c:1949)
                   ocfs2_write_end_inline (fs/ocfs2/aops.c:1915)
                     memcpy_from_folio     <-- KASAN: write OOB

So add id_count upper bound check in ocfs2_validate_inode_block() to
alongside the existing i_size check to fix it.

Link: https://lkml.kernel.org/r/20260403063830.3662739-1-joseph.qi@linux.alibaba.com
Signed-off-by: Joseph Qi 
Reported-by: syzbot+62c1793956716ea8b28a@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=62c1793956716ea8b28a
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Junxiao Bi 
Cc: Changwei Ge 
Cc: Jun Piao 
Cc: Heming Zhao 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ocfs2: validate inline data i_size during inode read

2026-04-22T11:30:50+00:00

[ Upstream commit 1524af3685b35feac76662cc551cbc37bd14775f ]

When reading an inode from disk, ocfs2_validate_inode_block() performs
various sanity checks but does not validate the size of inline data.  If
the filesystem is corrupted, an inode's i_size can exceed the actual
inline data capacity (id_count).

This causes ocfs2_dir_foreach_blk_id() to iterate beyond the inline data
buffer, triggering a use-after-free when accessing directory entries from
freed memory.

In the syzbot report:
  - i_size was 1099511627576 bytes (~1TB)
  - Actual inline data capacity (id_count) is typically <256 bytes
  - A garbage rec_len (54648) caused ctx->pos to jump out of bounds
  - This triggered a UAF in ocfs2_check_dir_entry()

Fix by adding a validation check in ocfs2_validate_inode_block() to ensure
inodes with inline data have i_size <= id_count.  This catches the
corruption early during inode read and prevents all downstream code from
operating on invalid data.

Link: https://lkml.kernel.org/r/20251212052132.16750-1-kartikey406@gmail.com
Signed-off-by: Deepanshu Kartikey 
Reported-by: syzbot+c897823f699449cc3eb4@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=c897823f699449cc3eb4
Tested-by: syzbot+c897823f699449cc3eb4@syzkaller.appspotmail.com
Link: https://lore.kernel.org/all/20251211115231.3560028-1-kartikey406@gmail.com/T/ [v1]
Link: https://lore.kernel.org/all/20251212040400.6377-1-kartikey406@gmail.com/T/ [v2]
Reviewed-by: Joseph Qi 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Junxiao Bi 
Cc: Changwei Ge 
Cc: Jun Piao 
Cc: Heming Zhao 
Signed-off-by: Andrew Morton 
Stable-dep-of: 7bc5da4842be ("ocfs2: fix out-of-bounds write in ocfs2_write_end_inline")
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

ocfs2: handle invalid dinode in ocfs2_group_extend

2026-04-22T11:30:48+00:00

commit 4a1c0ddc6e7bcf2e9db0eeaab9340dcfe97f448f upstream.

[BUG]
kernel BUG at fs/ocfs2/resize.c:308!
Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
RIP: 0010:ocfs2_group_extend+0x10aa/0x1ae0 fs/ocfs2/resize.c:308
Code: 8b8520ff ffff83f8 860f8580 030000e8 5cc3c1fe
Call Trace:
 ...
 ocfs2_ioctl+0x175/0x6e0 fs/ocfs2/ioctl.c:869
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl fs/ioctl.c:583 [inline]
 __x64_sys_ioctl+0x197/0x1e0 fs/ioctl.c:583
 x64_sys_call+0x1144/0x26a0 arch/x86/include/generated/asm/syscalls_64.h:17
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x93/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x76/0x7e
 ...

[CAUSE]
ocfs2_group_extend() assumes that the global bitmap inode block
returned from ocfs2_inode_lock() has already been validated and
BUG_ONs when the signature is not a dinode. That assumption is too
strong for crafted filesystems because the JBD2-managed buffer path
can bypass structural validation and return an invalid dinode to the
resize ioctl.

[FIX]
Validate the dinode explicitly in ocfs2_group_extend(). If the global
bitmap buffer does not contain a valid dinode, report filesystem
corruption with ocfs2_error() and fail the resize operation instead of
crashing the kernel.

Link: https://lkml.kernel.org/r/20260401092303.3709187-1-gality369@gmail.com
Fixes: 10995aa2451a ("ocfs2: Morph the haphazard OCFS2_IS_VALID_DINODE() checks.")
Signed-off-by: ZhengYuan Huang 
Reviewed-by: Joseph Qi 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Junxiao Bi 
Cc: Changwei Ge 
Cc: Jun Piao 
Cc: Heming Zhao 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

ocfs2: fix use-after-free in ocfs2_fault() when VM_FAULT_RETRY

2026-04-22T11:30:48+00:00

commit 7de554cabf160e331e4442e2a9ad874ca9875921 upstream.

filemap_fault() may drop the mmap_lock before returning VM_FAULT_RETRY,
as documented in mm/filemap.c:

  "If our return value has VM_FAULT_RETRY set, it's because the mmap_lock
  may be dropped before doing I/O or by lock_folio_maybe_drop_mmap()."

When this happens, a concurrent munmap() can call remove_vma() and free
the vm_area_struct via RCU. The saved 'vma' pointer in ocfs2_fault() then
becomes a dangling pointer, and the subsequent trace_ocfs2_fault() call
dereferences it -- a use-after-free.

Fix this by saving ip_blkno as a plain integer before calling
filemap_fault(), and removing vma from the trace event. Since
ip_blkno is copied by value before the lock can be dropped, it
remains valid regardless of what happens to the vma or inode
afterward.

Link: https://lkml.kernel.org/r/20260410083816.34951-1-tejas.bharambe@outlook.com
Fixes: 614a9e849ca6 ("ocfs2: Remove FILE_IO from masklog.")
Signed-off-by: Tejas Bharambe 
Reported-by: syzbot+a49010a0e8fcdeea075f@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=a49010a0e8fcdeea075f
Suggested-by: Joseph Qi 
Reviewed-by: Joseph Qi 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Junxiao Bi 
Cc: Changwei Ge 
Cc: Jun Piao 
Cc: Heming Zhao 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

ocfs2: fix possible deadlock between unlink and dio_end_io_write

2026-04-22T11:30:48+00:00

commit b02da26a992db0c0e2559acbda0fc48d4a2fd337 upstream.

ocfs2_unlink takes orphan dir inode_lock first and then ip_alloc_sem,
while in ocfs2_dio_end_io_write, it acquires these locks in reverse order.
This creates an ABBA lock ordering violation on lock classes
ocfs2_sysfile_lock_key[ORPHAN_DIR_SYSTEM_INODE] and
ocfs2_file_ip_alloc_sem_key.

Lock Chain #0 (orphan dir inode_lock -> ip_alloc_sem):
ocfs2_unlink
  ocfs2_prepare_orphan_dir
    ocfs2_lookup_lock_orphan_dir
      inode_lock(orphan_dir_inode) <- lock A
    __ocfs2_prepare_orphan_dir
      ocfs2_prepare_dir_for_insert
        ocfs2_extend_dir
	  ocfs2_expand_inline_dir
	    down_write(&oi->ip_alloc_sem) <- Lock B

Lock Chain #1 (ip_alloc_sem -> orphan dir inode_lock):
ocfs2_dio_end_io_write
  down_write(&oi->ip_alloc_sem) <- Lock B
  ocfs2_del_inode_from_orphan()
    inode_lock(orphan_dir_inode) <- Lock A

Deadlock Scenario:
  CPU0 (unlink)                     CPU1 (dio_end_io_write)
  ------                            ------
  inode_lock(orphan_dir_inode)
                                    down_write(ip_alloc_sem)
  down_write(ip_alloc_sem)
                                    inode_lock(orphan_dir_inode)

Since ip_alloc_sem is to protect allocation changes, which is unrelated
with operations in ocfs2_del_inode_from_orphan.  So move
ocfs2_del_inode_from_orphan out of ip_alloc_sem to fix the deadlock.

Link: https://lkml.kernel.org/r/20260306032211.1016452-1-joseph.qi@linux.alibaba.com
Reported-by: syzbot+67b90111784a3eac8c04@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=67b90111784a3eac8c04
Fixes: a86a72a4a4e0 ("ocfs2: take ip_alloc_sem in ocfs2_dio_get_block & ocfs2_dio_end_io_write")
Signed-off-by: Joseph Qi 
Reviewed-by: Heming Zhao 
Cc: Mark Fasheh 
Cc: Joel Becker 
Cc: Junxiao Bi 
Cc: Joseph Qi 
Cc: Changwei Ge 
Cc: Jun Piao 
Cc: 
Signed-off-by: Andrew Morton 
Signed-off-by: Greg Kroah-Hartman

dcache: Limit the minimal number of bucket to two

2026-04-22T11:30:48+00:00

commit f08fe8891c3eeb63b73f9f1f6d97aa629c821579 upstream.

There is an OOB read problem on dentry_hashtable when user sets
'dhash_entries=1':
  BUG: unable to handle page fault for address: ffff888b30b774b0
  #PF: supervisor read access in kernel mode
  #PF: error_code(0x0000) - not-present page
  Oops: Oops: 0000 [#1] SMP PTI
  RIP: 0010:__d_lookup+0x56/0x120
   Call Trace:
    d_lookup.cold+0x16/0x5d
    lookup_dcache+0x27/0xf0
    lookup_one_qstr_excl+0x2a/0x180
    start_dirop+0x55/0xa0
    simple_start_creating+0x8d/0xa0
    debugfs_start_creating+0x8c/0x180
    debugfs_create_dir+0x1d/0x1c0
    pinctrl_init+0x6d/0x140
    do_one_initcall+0x6d/0x3d0
    kernel_init_freeable+0x39f/0x460
    kernel_init+0x2a/0x260

There will be only one bucket in dentry_hashtable when dhash_entries is
set as one, and d_hash_shift is calculated as 32 by dcache_init(). Then,
following process will access more than one buckets(which memory region
is not allocated) in dentry_hashtable:
 d_lookup
  b = d_hash(hash)
    dentry_hashtable + ((u32)hashlen >> d_hash_shift)
    // The C standard defines the behavior of right shift amounts
    // exceeding the bit width of the operand as undefined. The
    // result of '(u32)hashlen >> d_hash_shift' becomes 'hashlen',
    // so 'b' will point to an unallocated memory region.
  hlist_bl_for_each_entry_rcu(b)
   hlist_bl_first_rcu(head)
    h->first  // read OOB!

Fix it by limiting the minimal number of dentry_hashtable bucket to two,
so that 'd_hash_shift' won't exceeds the bit width of type u32.

Cc: stable@vger.kernel.org
Signed-off-by: Zhihao Cheng 
Link: https://patch.msgid.link/20260130034853.215819-1-chengzhihao1@huawei.com
Reviewed-by: Yang Erkun 
Signed-off-by: Christian Brauner 
Signed-off-by: Greg Kroah-Hartman

smb: server: avoid double-free in smb_direct_free_sendmsg after smb_direct_flush_send_list()

2026-04-22T11:30:46+00:00

commit 84ff995ae826aa6bbcc6c7b9ea569ff67c021d72 upstream.

smb_direct_flush_send_list() already calls smb_direct_free_sendmsg(),
so we should not call it again after post_sendmsg()
moved it to the batch list.

Reported-by: Ruikai Peng 
Closes: https://lore.kernel.org/linux-cifs/CAFD3drNOSJ05y3A+jNXSDxW-2w09KHQ0DivhxQ_pcc7immVVOQ@mail.gmail.com/
Fixes: 34abd408c8ba ("smb: server: make use of smbdirect_socket.send_io.bcredits")
Cc: stable@kernel.org
Cc: Steve French 
Cc: Tom Talpey 
Cc: Ruikai Peng 
Cc: Sergey Senozhatsky 
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Cc: security@kernel.org
Signed-off-by: Stefan Metzmacher 
Acked-by: Namjae Jeon 
Acked-by: Paulo Alcantara (Red Hat) 
Tested-by: Ruikai Peng 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

smb: client: avoid double-free in smbd_free_send_io() after smbd_send_batch_flush()

2026-04-22T11:30:46+00:00

commit 27b7c3e916218b5eb2ee350211140e961bfc49be upstream.

smbd_send_batch_flush() already calls smbd_free_send_io(),
so we should not call it again after smbd_post_send()
moved it to the batch list.

Reported-by: Ruikai Peng 
Closes: https://lore.kernel.org/linux-cifs/CAFD3drNOSJ05y3A+jNXSDxW-2w09KHQ0DivhxQ_pcc7immVVOQ@mail.gmail.com/
Fixes: 21538121efe6 ("smb: client: make use of smbdirect_socket.send_io.bcredits")
Cc: stable@kernel.org
Cc: Steve French 
Cc: Tom Talpey 
Cc: Long Li 
Cc: Ruikai Peng 
Cc: Sergey Senozhatsky 
Cc: linux-cifs@vger.kernel.org
Cc: samba-technical@lists.samba.org
Cc: security@kernel.org
Acked-by: Paulo Alcantara (Red Hat) 
Acked-by: Namjae Jeon 
Signed-off-by: Stefan Metzmacher 
Tested-by: Ruikai Peng 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman

ksmbd: fix mechToken leak when SPNEGO decode fails after token alloc

2026-04-22T11:30:46+00:00

commit ad0057fb91218914d6c98268718ceb9d59b388e1 upstream.

The kernel ASN.1 BER decoder calls action callbacks incrementally as it
walks the input.  When ksmbd_decode_negTokenInit() reaches the mechToken
[2] OCTET STRING element, ksmbd_neg_token_alloc() allocates
conn->mechToken immediately via kmemdup_nul().  If a later element in
the same blob is malformed, then the decoder will return nonzero after
the allocation is already live.  This could happen if mechListMIC [3]
overrunse the enclosing SEQUENCE.

decode_negotiation_token() then sets conn->use_spnego = false because
both the negTokenInit and negTokenTarg grammars failed.  The cleanup at
the bottom of smb2_sess_setup() is gated on use_spnego:

	if (conn->use_spnego && conn->mechToken) {
		kfree(conn->mechToken);
		conn->mechToken = NULL;
	}

so the kfree is skipped, causing the mechToken to never be freed.

This codepath is reachable pre-authentication, so untrusted clients can
cause slow memory leaks on a server without even being properly
authenticated.

Fix this up by not checking check for use_spnego, as it's not required,
so the memory will always be properly freed.  At the same time, always
free the memory in ksmbd_conn_free() incase some other failure path
forgot to free it.

Cc: Namjae Jeon 
Cc: Steve French 
Cc: Sergey Senozhatsky 
Cc: Tom Talpey 
Cc: linux-cifs@vger.kernel.org
Cc: 
Assisted-by: gregkh_clanker_t1000
Signed-off-by: Greg Kroah-Hartman 
Acked-by: Namjae Jeon 
Signed-off-by: Steve French 
Signed-off-by: Greg Kroah-Hartman