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Fencer Vulns
high 7.1

CVE-2022-49738 json

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

published 2025-03-27 19 mo ago modified 2026-08-15 2 mo ago also EUVD-2022-55185

cvss
7.1
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 9%
public exploits
0
none known

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: 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

Patch / fix

  • Linux Linux 5.4.232, 5.10.168, 5.15.93, 6.1.11, 6.2
  • linux Debian 14, Debian 13, Debian 12 6.1.11-1

debian advisories DEBIAN-CVE-2022-49738

  • linux Ubuntu 20.04 LTS 5.4.0-149.166
  • linux Ubuntu 22.04 LTS 5.15.0-72.79
  • linux-aws Ubuntu 20.04 LTS 5.4.0-1102.110
  • linux-aws Ubuntu 22.04 LTS 5.15.0-1036.40
  • linux-gcp Ubuntu 20.04 LTS 5.4.0-1105.114
  • linux-gcp Ubuntu 22.04 LTS 5.15.0-1034.42
  • linux-gke Ubuntu 22.04 LTS 5.15.0-1033.38
  • linux-ibm Ubuntu 20.04 LTS 5.4.0-1049.54

ubuntu advisories UBUNTU-CVE-2022-49738

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2022-49738 updated cvss 7.1

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

  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
13 mo ago

Exploit prediction

0.20% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.1 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
CISA ADP 3.1 7.1 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
NVD 3.1 7.1 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.