f2fs: don't reset unchangable mount option in f2fs_remount()

Description

In the Linux kernel, the following vulnerability has been resolved: f2fs: don't reset unchangable mount option in f2fs_remount() syzbot reports a bug as below: general protection fault, probably for non-canonical address 0xdffffc0000000009: 0000 [#1] PREEMPT SMP KASAN RIP: 0010:__lock_acquire+0x69/0x2000 kernel/locking/lockdep.c:4942 Call Trace: lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5691 __raw_write_lock include/linux/rwlock_api_smp.h:209 [inline] _raw_write_lock+0x2e/0x40 kernel/locking/spinlock.c:300 __drop_extent_tree+0x3ac/0x660 fs/f2fs/extent_cache.c:1100 f2fs_drop_extent_tree+0x17/0x30 fs/f2fs/extent_cache.c:1116 f2fs_insert_range+0x2d5/0x3c0 fs/f2fs/file.c:1664 f2fs_fallocate+0x4e4/0x6d0 fs/f2fs/file.c:1838 vfs_fallocate+0x54b/0x6b0 fs/open.c:324 ksys_fallocate fs/open.c:347 [inline] __do_sys_fallocate fs/open.c:355 [inline] __se_sys_fallocate fs/open.c:353 [inline] __x64_sys_fallocate+0xbd/0x100 fs/open.c:353 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd The root cause is race condition as below: - since it tries to remount rw filesystem, so that do_remount won't call sb_prepare_remount_readonly to block fallocate, there may be race condition in between remount and fallocate. - in f2fs_remount(), default_options() will reset mount option to default one, and then update it based on result of parse_options(), so there is a hole which race condition can happen. Thread A Thread B - f2fs_fill_super - parse_options - clear_opt(READ_EXTENT_CACHE) - f2fs_remount - default_options - set_opt(READ_EXTENT_CACHE) - f2fs_fallocate - f2fs_insert_range - f2fs_drop_extent_tree - __drop_extent_tree - __may_extent_tree - test_opt(READ_EXTENT_CACHE) return true - write_lock(&et->lock) access NULL pointer - parse_options - clear_opt(READ_EXTENT_CACHE)

Scores

EPSS (exploitation in 30 days)

0.11% · top 99% of all CVEs (6 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: no · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 4.7.

Weakness

• CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') (opens in a new tab)All about CWE-362 and its CVEs

Affected products

• Linux · Linux

  • affected 98e4da8ca301e062d79ae168c67e56f3c3de3ce4 – < f6464b3c31344af4964443dbbcb4596ac9b46519
  • affected 98e4da8ca301e062d79ae168c67e56f3c3de3ce4 – < 115557cc226a927924f2d7d1980ccbf6e3b3bb36
  • affected 98e4da8ca301e062d79ae168c67e56f3c3de3ce4 – < 458c15dfbce62c35fefd9ca637b20a051309c9f1

• Linux · Linux

  • affected 3.8
  • unaffected < 3.8
  • unaffected 6.1.191 – ≤ 6.1.*
  • unaffected 6.4.5 – ≤ 6.4.*
  • unaffected 6.5 – ≤ *

References (3)

• https://git.kernel.org/stable/c/f6464b3c31344af4964443dbbcb4596ac9b46519 (opens in a new tab)
• https://git.kernel.org/stable/c/115557cc226a927924f2d7d1980ccbf6e3b3bb36 (opens in a new tab)
• https://git.kernel.org/stable/c/458c15dfbce62c35fefd9ca637b20a051309c9f1 (opens in a new tab)

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2023-53447](https://trackcve.app/badge/CVE-2023-53447.svg)](https://trackcve.app/cve/CVE-2023-53447)

Record last updated 30 Oct 2026, 12:17 UTC.