{"id":"CVE-2023-53447","title":"f2fs: don't reset unchangable mount option in f2fs_remount()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: don't reset unchangable mount option in f2fs_remount()\n\nsyzbot reports a bug as below:\n\ngeneral protection fault, probably for non-canonical address 0xdffffc00000…","severity":"medium","cvss":4.7,"cvssVector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H","cvssSource":"adp","vendor":"Linux","product":"Linux","affected":["Linux >= 98e4da8ca301e062d79ae168c67e56f3c3de3ce4 < f6464b3c31344af4964443dbbcb4596ac9b46519","Linux >= 98e4da8ca301e062d79ae168c67e56f3c3de3ce4 < 115557cc226a927924f2d7d1980ccbf6e3b3bb36","Linux >= 98e4da8ca301e062d79ae168c67e56f3c3de3ce4 < 458c15dfbce62c35fefd9ca637b20a051309c9f1","Linux 3.8"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-01-14T19:19:57.010722Z"},"published":"2025-09-18","updated":"2026-10-30","sourceUpdated":"2026-10-30T12:17:30.478Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2023-53447","references":[{"url":"https://git.kernel.org/stable/c/f6464b3c31344af4964443dbbcb4596ac9b46519"},{"url":"https://git.kernel.org/stable/c/115557cc226a927924f2d7d1980ccbf6e3b3bb36"},{"url":"https://git.kernel.org/stable/c/458c15dfbce62c35fefd9ca637b20a051309c9f1"}],"tags":["cve.org"],"epss":0.00108,"epssPercentile":0.01199,"ingestedAt":"2026-11-03T11:43:15.786Z","slug":"CVE-2023-53447","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: don't reset unchangable mount option in f2fs_remount()\n\nsyzbot reports a bug as below:\n\ngeneral protection fault, probably for non-canonical address 0xdffffc0000000009: 0000 [#1] PREEMPT SMP KASAN\nRIP: 0010:__lock_acquire+0x69/0x2000 kernel/locking/lockdep.c:4942\nCall Trace:\n lock_acquire+0x1e3/0x520 kernel/locking/lockdep.c:5691\n __raw_write_lock include/linux/rwlock_api_smp.h:209 [inline]\n _raw_write_lock+0x2e/0x40 kernel/locking/spinlock.c:300\n __drop_extent_tree+0x3ac/0x660 fs/f2fs/extent_cache.c:1100\n f2fs_drop_extent_tree+0x17/0x30 fs/f2fs/extent_cache.c:1116\n f2fs_insert_range+0x2d5/0x3c0 fs/f2fs/file.c:1664\n f2fs_fallocate+0x4e4/0x6d0 fs/f2fs/file.c:1838\n vfs_fallocate+0x54b/0x6b0 fs/open.c:324\n ksys_fallocate fs/open.c:347 [inline]\n __do_sys_fallocate fs/open.c:355 [inline]\n __se_sys_fallocate fs/open.c:353 [inline]\n __x64_sys_fallocate+0xbd/0x100 fs/open.c:353\n do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80\n entry_SYSCALL_64_after_hwframe+0x63/0xcd\n\nThe root cause is race condition as below:\n- since it tries to remount rw filesystem, so that do_remount won't\ncall sb_prepare_remount_readonly to block fallocate, there may be race\ncondition in between remount and fallocate.\n- in f2fs_remount(), default_options() will reset mount option to default\none, and then update it based on result of parse_options(), so there is\na hole which race condition can happen.\n\nThread A\t\t\tThread B\n- f2fs_fill_super\n - parse_options\n  - clear_opt(READ_EXTENT_CACHE)\n\n- f2fs_remount\n - default_options\n  - set_opt(READ_EXTENT_CACHE)\n\t\t\t\t- f2fs_fallocate\n\t\t\t\t - f2fs_insert_range\n\t\t\t\t  - f2fs_drop_extent_tree\n\t\t\t\t   - __drop_extent_tree\n\t\t\t\t    - __may_extent_tree\n\t\t\t\t     - test_opt(READ_EXTENT_CACHE) return true\n\t\t\t\t    - write_lock(&et->lock) access NULL pointer\n - parse_options\n  - clear_opt(READ_EXTENT_CACHE)\n\n## Affected\n\n- `Linux >= 98e4da8ca301e062d79ae168c67e56f3c3de3ce4 < f6464b3c31344af4964443dbbcb4596ac9b46519`\n- `Linux >= 98e4da8ca301e062d79ae168c67e56f3c3de3ce4 < 115557cc226a927924f2d7d1980ccbf6e3b3bb36`\n- `Linux >= 98e4da8ca301e062d79ae168c67e56f3c3de3ce4 < 458c15dfbce62c35fefd9ca637b20a051309c9f1`\n- `Linux 3.8`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":26,"depthScoreParts":{"impact":25.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}