{"id":"CVE-2021-47335","state":"PUBLISHED","title":"f2fs: fix to avoid racing on fsync_entry_slab by multi filesystem instances","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to avoid racing on fsync_entry_slab by multi filesystem instances\n\nAs syzbot reported, there is an use-after-free issue during f2fs recovery:\n\nUse-after-free write at 0xffff88823bc16040 (in kfence-#10):\n kmem_cache_destroy+0x1f/0x120 mm/slab_common.c:486\n f2fs_recover_fsync_data+0x75b0/0x8380 fs/f2fs/recovery.c:869\n f2fs_fill_super+0x9393/0xa420 fs/f2fs/super.c:3945\n mount_bdev+0x26c/0x3a0 fs/super.c:1367\n legacy_get_tree+0xea/0x180 fs/fs_context.c:592\n vfs_get_tree+0x86/0x270 fs/super.c:1497\n do_new_mount fs/namespace.c:2905 [inline]\n path_mount+0x196f/0x2be0 fs/namespace.c:3235\n do_mount fs/namespace.c:3248 [inline]\n __do_sys_mount fs/namespace.c:3456 [inline]\n __se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3433\n do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47\n entry_SYSCALL_64_after_hwframe+0x44/0xae\n\nThe root cause is multi f2fs filesystem instances can race on accessing\nglobal fsync_entry_slab pointer, result in use-after-free issue of slab\ncache, fixes to init/destroy this slab cache only once during module\ninit/destroy procedure to avoid this issue.","publishedAt":"2024-05-21T14:35:45.093Z","updatedAt":"2026-08-11T02:05:14.637Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d624c96fb3249e5d3dcf4e60a805e5e6b0dd7d91","status":"affected","lessThan":"86786603014e0a22d0d6af8e80ae4b8687927048","versionType":"git"},{"version":"d624c96fb3249e5d3dcf4e60a805e5e6b0dd7d91","status":"affected","lessThan":"79fa5d944c875711253a23b8155b36883c696409","versionType":"git"},{"version":"d624c96fb3249e5d3dcf4e60a805e5e6b0dd7d91","status":"affected","lessThan":"e472b276a0d2180808009be38105e12754432e2a","versionType":"git"},{"version":"d624c96fb3249e5d3dcf4e60a805e5e6b0dd7d91","status":"affected","lessThan":"cad83c968c2ebe97905f900326988ed37146c347","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/f2fs.h","fs/f2fs/recovery.c","fs/f2fs/super.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.8","versionType":"semver"},{"version":"5.10.51","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.12.18","status":"unaffected","lessThanOrEqual":"5.12.*","versionType":"semver"},{"version":"5.13.3","status":"unaffected","lessThanOrEqual":"5.13.*","versionType":"semver"},{"version":"5.14","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/f2fs.h","fs/f2fs/recovery.c","fs/f2fs/super.c"]}],"references":["https://git.kernel.org/stable/c/86786603014e0a22d0d6af8e80ae4b8687927048","https://git.kernel.org/stable/c/79fa5d944c875711253a23b8155b36883c696409","https://git.kernel.org/stable/c/e472b276a0d2180808009be38105e12754432e2a","https://git.kernel.org/stable/c/cad83c968c2ebe97905f900326988ed37146c347"],"weaknesses":[],"ingestedAt":"2026-10-29T19:49:19.404Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2021/47xxx/CVE-2021-47335.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2021-47335","state":"PUBLISHED","datePublished":"2024-05-21T14:35:45.093Z","dateUpdated":"2026-08-11T02:05:14.637Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-05-21T14:28:16.977Z"},"containers":{"cna":{"title":"f2fs: fix to avoid racing on fsync_entry_slab by multi filesystem instances","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: fix to avoid racing on fsync_entry_slab by multi filesystem instances\n\nAs syzbot reported, there is an use-after-free issue during f2fs recovery:\n\nUse-after-free write at 0xffff88823bc16040 (in kfence-#10):\n kmem_cache_destroy+0x1f/0x120 mm/slab_common.c:486\n f2fs_recover_fsync_data+0x75b0/0x8380 fs/f2fs/recovery.c:869\n f2fs_fill_super+0x9393/0xa420 fs/f2fs/super.c:3945\n mount_bdev+0x26c/0x3a0 fs/super.c:1367\n legacy_get_tree+0xea/0x180 fs/fs_context.c:592\n vfs_get_tree+0x86/0x270 fs/super.c:1497\n do_new_mount fs/namespace.c:2905 [inline]\n path_mount+0x196f/0x2be0 fs/namespace.c:3235\n do_mount fs/namespace.c:3248 [inline]\n __do_sys_mount fs/namespace.c:3456 [inline]\n __se_sys_mount+0x2f9/0x3b0 fs/namespace.c:3433\n do_syscall_64+0x3f/0xb0 arch/x86/entry/common.c:47\n entry_SYSCALL_64_after_hwframe+0x44/0xae\n\nThe root cause is multi f2fs filesystem instances can race on accessing\nglobal fsync_entry_slab pointer, result in use-after-free issue of slab\ncache, fixes to init/destroy this slab cache only once during module\ninit/destroy procedure to avoid this issue."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"d624c96fb3249e5d3dcf4e60a805e5e6b0dd7d91","status":"affected","lessThan":"86786603014e0a22d0d6af8e80ae4b8687927048","versionType":"git"},{"version":"d624c96fb3249e5d3dcf4e60a805e5e6b0dd7d91","status":"affected","lessThan":"79fa5d944c875711253a23b8155b36883c696409","versionType":"git"},{"version":"d624c96fb3249e5d3dcf4e60a805e5e6b0dd7d91","status":"affected","lessThan":"e472b276a0d2180808009be38105e12754432e2a","versionType":"git"},{"version":"d624c96fb3249e5d3dcf4e60a805e5e6b0dd7d91","status":"affected","lessThan":"cad83c968c2ebe97905f900326988ed37146c347","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/f2fs.h","fs/f2fs/recovery.c","fs/f2fs/super.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.8","versionType":"semver"},{"version":"5.10.51","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.12.18","status":"unaffected","lessThanOrEqual":"5.12.*","versionType":"semver"},{"version":"5.13.3","status":"unaffected","lessThanOrEqual":"5.13.*","versionType":"semver"},{"version":"5.14","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/f2fs/f2fs.h","fs/f2fs/recovery.c","fs/f2fs/super.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/86786603014e0a22d0d6af8e80ae4b8687927048"},{"url":"https://git.kernel.org/stable/c/79fa5d944c875711253a23b8155b36883c696409"},{"url":"https://git.kernel.org/stable/c/e472b276a0d2180808009be38105e12754432e2a"},{"url":"https://git.kernel.org/stable/c/cad83c968c2ebe97905f900326988ed37146c347"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-11T02:05:14.637Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"5.10.51"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"5.12.18"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"5.13.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"5.14"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA 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