---
id: CVE-2022-49738
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  f2fs: fix to do sanity check on i_extra_isize in is_alive()

  syzbot found a f2fs bug:

  BUG: KASAN: slab-out-of-bounds in data_blkaddr fs/f2fs/f2fs.h:2891 [inline]
  BUG: …
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  f2fs: fix to do sanity check on i_extra_isize in is_alive()

  syzbot found a f2fs bug:

  BUG: KASAN: slab-out-of-bounds in data_blkaddr fs/f2fs/f2fs.h:2891 [inline]
  BUG: …
severity: high
cvss: 7.1
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H'
cwe:
  - CWE-125
vendor: linux
product: linux_kernel
affected:
  - linux_kernel < 5.4.232
  - 'linux_kernel >= 5.5, < 5.10.168'
  - 'linux_kernel >= 5.11, < 5.15.93'
  - 'linux_kernel >= 5.16, < 6.1.11'
patched:
  - linux_kernel 6.1.11
published: '2025-03-27'
updated: '2026-08-15'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2022-49738'
references:
  - url: 'https://git.kernel.org/stable/c/5b25035fb888cb2f78bf0b9c9f95b1dc54480d36'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/914e38f02a490dafd980ff0f39cccedc074deb29'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/97ccfffcc061e54ce87e4a51a40e2e9cb0b7076a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/d3b7b4afd6b2c344eabf9cc26b8bfa903c164c7c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/e5142a4935c1f15841d06047b8130078fc4d7b8f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2022/cve-2022-49738.json
  - url: 'https://access.redhat.com/security/cve/CVE-2022-49738'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2355467'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2022-49738'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2022-49738'
  - url: >-
      https://lore.kernel.org/linux-cve-announce/2025032756-CVE-2022-49738-c2ef@gregkh/T
tags:
  - nvd
  - csaf
  - vex
  - red-hat
epss: 0.00195
epssPercentile: 0.08157
ingestedAt: '2026-08-15T13:26:44.620Z'
---

## Overview

In the Linux kernel, the following vulnerability has been resolved:

f2fs: fix to do sanity check on i_extra_isize in is_alive()

syzbot found a f2fs bug:

BUG: KASAN: slab-out-of-bounds in data_blkaddr fs/f2fs/f2fs.h:2891 [inline]
BUG: KASAN: slab-out-of-bounds in is_alive fs/f2fs/gc.c:1117 [inline]
BUG: KASAN: slab-out-of-bounds in gc_data_segment fs/f2fs/gc.c:1520 [inline]
BUG: KASAN: slab-out-of-bounds in do_garbage_collect+0x386a/0x3df0 fs/f2fs/gc.c:1734
Read of size 4 at addr ffff888076557568 by task kworker/u4:3/52

CPU: 1 PID: 52 Comm: kworker/u4:3 Not tainted 6.1.0-rc4-syzkaller-00362-gfef7fd48922d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Workqueue: writeback wb_workfn (flush-7:0)
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:284 [inline]
print_report+0x15e/0x45d mm/kasan/report.c:395
kasan_report+0xbb/0x1f0 mm/kasan/report.c:495
data_blkaddr fs/f2fs/f2fs.h:2891 [inline]
is_alive fs/f2fs/gc.c:1117 [inline]
gc_data_segment fs/f2fs/gc.c:1520 [inline]
do_garbage_collect+0x386a/0x3df0 fs/f2fs/gc.c:1734
f2fs_gc+0x88c/0x20a0 fs/f2fs/gc.c:1831
f2fs_balance_fs+0x544/0x6b0 fs/f2fs/segment.c:410
f2fs_write_inode+0x57e/0xe20 fs/f2fs/inode.c:753
write_inode fs/fs-writeback.c:1440 [inline]
__writeback_single_inode+0xcfc/0x1440 fs/fs-writeback.c:1652
writeback_sb_inodes+0x54d/0xf90 fs/fs-writeback.c:1870
wb_writeback+0x2c5/0xd70 fs/fs-writeback.c:2044
wb_do_writeback fs/fs-writeback.c:2187 [inline]
wb_workfn+0x2dc/0x12f0 fs/fs-writeback.c:2227
process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289
worker_thread+0x665/0x1080 kernel/workqueue.c:2436
kthread+0x2e4/0x3a0 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306

The root cause is that we forgot to do sanity check on .i_extra_isize
in below path, result in accessing invalid address later, fix it.
- gc_data_segment
 - is_alive
  - data_blkaddr
   - offset_in_addr

## Affected

- `linux_kernel < 5.4.232`
- `linux_kernel >= 5.5, < 5.10.168`
- `linux_kernel >= 5.11, < 5.15.93`
- `linux_kernel >= 5.16, < 6.1.11`

## Remediation

Upgrade past the affected range:

- `linux_kernel 6.1.11`

## Vendor advisories

- **Red Hat VEX** · Important · updated 2026-09-13 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2022/cve-2022-49738.json)