Bug 2536176 (CVE-2026-90320) - CVE-2026-90320 kernel: ocfs2: validate external xattr entries when reading metadata
Summary: CVE-2026-90320 kernel: ocfs2: validate external xattr entries when reading me...
Keywords:
Status: NEW
Alias: CVE-2026-90320
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-17 16:41 UTC by OSIDB Bzimport
Modified: 2026-10-13 14:16 UTC (History)
17 users (show)

Fixed In Version:
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Description OSIDB Bzimport 2026-09-17 16:41:31 UTC
In the Linux kernel, the following vulnerability has been resolved:

ocfs2: validate external xattr entries when reading metadata

ocfs2_validate_xattr_block() checks the xattr block header before the
block reaches higher-level xattr users, but it does not verify that a
non-indexed block's xh_count and entry offsets fit inside the block. 
Indexed buckets likewise reach list/get consumers after ECC without an
entry-bounds check.

Use the flat xattr entry validator for non-indexed external xattr blocks,
and use a bucket-specific validator for indexed buckets at metadata read
time.  The bucket validator keeps the entry array bounded by the first
bucket block while checking name/value offsets against the bucket block
they target.

Reject corrupted external xattr metadata before listxattr() or getxattr()
can walk out-of-range entry arrays or name/value offsets.

Validation reproduced this kernel report:
BUG: KASAN: use-after-free in ocfs2_xattr_list_entries+0xd7/0x190
Read of size 1 at addr ffff88810a654007 by task ocfs2_xattr_lis/630
Call Trace:
  dump_stack_lvl+0x66/0xa0
  print_report+0xce/0x630
  kasan_report+0xe0/0x110
  ocfs2_xattr_list_entries+0xd7/0x190
  ocfs2_listxattr+0x3f6/0x610
  listxattr+0x90/0xe0
  path_listxattrat+0xed/0x220
  do_syscall_64+0x115/0x6a0
  entry_SYSCALL_64_after_hwframe+0x77/0x7f


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