{"id":"CVE-2023-53100","state":"PUBLISHED","title":"ext4: fix WARNING in ext4_update_inline_data","description":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix WARNING in ext4_update_inline_data\n\nSyzbot found the following issue:\nEXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 without journal. Quota mode: none.\nfscrypt: AES-256-CTS-CBC using implementation \"cts-cbc-aes-aesni\"\nfscrypt: AES-256-XTS using implementation \"xts-aes-aesni\"\n------------[ cut here ]------------\nWARNING: CPU: 0 PID: 5071 at mm/page_alloc.c:5525 __alloc_pages+0x30a/0x560 mm/page_alloc.c:5525\nModules linked in:\nCPU: 1 PID: 5071 Comm: syz-executor263 Not tainted 6.2.0-rc1-syzkaller #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022\nRIP: 0010:__alloc_pages+0x30a/0x560 mm/page_alloc.c:5525\nRSP: 0018:ffffc90003c2f1c0 EFLAGS: 00010246\nRAX: ffffc90003c2f220 RBX: 0000000000000014 RCX: 0000000000000000\nRDX: 0000000000000028 RSI: 0000000000000000 RDI: ffffc90003c2f248\nRBP: ffffc90003c2f2d8 R08: dffffc0000000000 R09: ffffc90003c2f220\nR10: fffff52000785e49 R11: 1ffff92000785e44 R12: 0000000000040d40\nR13: 1ffff92000785e40 R14: dffffc0000000000 R15: 1ffff92000785e3c\nFS:  0000555556c0d300(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007f95d5e04138 CR3: 00000000793aa000 CR4: 00000000003506f0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n <TASK>\n __alloc_pages_node include/linux/gfp.h:237 [inline]\n alloc_pages_node include/linux/gfp.h:260 [inline]\n __kmalloc_large_node+0x95/0x1e0 mm/slab_common.c:1113\n __do_kmalloc_node mm/slab_common.c:956 [inline]\n __kmalloc+0xfe/0x190 mm/slab_common.c:981\n kmalloc include/linux/slab.h:584 [inline]\n kzalloc include/linux/slab.h:720 [inline]\n ext4_update_inline_data+0x236/0x6b0 fs/ext4/inline.c:346\n ext4_update_inline_dir fs/ext4/inline.c:1115 [inline]\n ext4_try_add_inline_entry+0x328/0x990 fs/ext4/inline.c:1307\n ext4_add_entry+0x5a4/0xeb0 fs/ext4/namei.c:2385\n ext4_add_nondir+0x96/0x260 fs/ext4/namei.c:2772\n ext4_create+0x36c/0x560 fs/ext4/namei.c:2817\n lookup_open fs/namei.c:3413 [inline]\n open_last_lookups fs/namei.c:3481 [inline]\n path_openat+0x12ac/0x2dd0 fs/namei.c:3711\n do_filp_open+0x264/0x4f0 fs/namei.c:3741\n do_sys_openat2+0x124/0x4e0 fs/open.c:1310\n do_sys_open fs/open.c:1326 [inline]\n __do_sys_openat fs/open.c:1342 [inline]\n __se_sys_openat fs/open.c:1337 [inline]\n __x64_sys_openat+0x243/0x290 fs/open.c:1337\n do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80\n entry_SYSCALL_64_after_hwframe+0x63/0xcd\n\nAbove issue happens as follows:\next4_iget\n   ext4_find_inline_data_nolock ->i_inline_off=164 i_inline_size=60\next4_try_add_inline_entry\n   __ext4_mark_inode_dirty\n      ext4_expand_extra_isize_ea ->i_extra_isize=32 s_want_extra_isize=44\n         ext4_xattr_shift_entries\n\t ->after shift i_inline_off is incorrect, actually is change to 176\next4_try_add_inline_entry\n  ext4_update_inline_dir\n    get_max_inline_xattr_value_size\n      if (EXT4_I(inode)->i_inline_off)\n\tentry = (struct ext4_xattr_entry *)((void *)raw_inode +\n\t\t\tEXT4_I(inode)->i_inline_off);\n        free += EXT4_XATTR_SIZE(le32_to_cpu(entry->e_value_size));\n\t->As entry is incorrect, then 'free' may be negative\n   ext4_update_inline_data\n      value = kzalloc(len, GFP_NOFS);\n      -> len is unsigned int, maybe very large, then trigger warning when\n         'kzalloc()'\n\nTo resolve the above issue we need to update 'i_inline_off' after\n'ext4_xattr_shift_entries()'.  We do not need to set\nEXT4_STATE_MAY_INLINE_DATA flag here, since ext4_mark_inode_dirty()\nalready sets this flag if needed.  Setting EXT4_STATE_MAY_INLINE_DATA\nwhen it is needed may trigger a BUG_ON in ext4_writepages().","publishedAt":"2025-05-02T15:55:43.113Z","updatedAt":"2026-10-15T21:41:26.510Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"67cf5b09a46f72e048501b84996f2f77bc42e947","status":"affected","lessThan":"c5aa102b433b1890e1ccaa40c06826c77dda1665","versionType":"git"},{"version":"67cf5b09a46f72e048501b84996f2f77bc42e947","status":"affected","lessThan":"39c5df2ca544368b44b59d0f6d80131e90763371","versionType":"git"},{"version":"67cf5b09a46f72e048501b84996f2f77bc42e947","status":"affected","lessThan":"74d775083e9f3d9dadf9e3b5f3e0028d1ad0bd5c","versionType":"git"},{"version":"67cf5b09a46f72e048501b84996f2f77bc42e947","status":"affected","lessThan":"a9bd94f67b27739bbe8583c52256502bd4cc7e83","versionType":"git"},{"version":"67cf5b09a46f72e048501b84996f2f77bc42e947","status":"affected","lessThan":"ca500cf2eceb5a8e93bf71ab97b5f7a18ecabce2","versionType":"git"},{"version":"67cf5b09a46f72e048501b84996f2f77bc42e947","status":"affected","lessThan":"35161cec76772f74526f5886ad4082ec48511d5c","versionType":"git"},{"version":"67cf5b09a46f72e048501b84996f2f77bc42e947","status":"affected","lessThan":"92eee6a82a9a6f9f83559e17a2b6b935e1a5cd25","versionType":"git"},{"version":"67cf5b09a46f72e048501b84996f2f77bc42e947","status":"affected","lessThan":"2b96b4a5d9443ca4cad58b0040be455803c05a42","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ext4/xattr.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.8","versionType":"semver"},{"version":"4.14.310","status":"unaffected","lessThanOrEqual":"4.14.*","versionType":"semver"},{"version":"4.19.278","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.237","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.175","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.103","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.20","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.2.7","status":"unaffected","lessThanOrEqual":"6.2.*","versionType":"semver"},{"version":"6.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ext4/xattr.c"]}],"references":["https://git.kernel.org/stable/c/c5aa102b433b1890e1ccaa40c06826c77dda1665","https://git.kernel.org/stable/c/39c5df2ca544368b44b59d0f6d80131e90763371","https://git.kernel.org/stable/c/74d775083e9f3d9dadf9e3b5f3e0028d1ad0bd5c","https://git.kernel.org/stable/c/a9bd94f67b27739bbe8583c52256502bd4cc7e83","https://git.kernel.org/stable/c/ca500cf2eceb5a8e93bf71ab97b5f7a18ecabce2","https://git.kernel.org/stable/c/35161cec76772f74526f5886ad4082ec48511d5c","https://git.kernel.org/stable/c/92eee6a82a9a6f9f83559e17a2b6b935e1a5cd25","https://git.kernel.org/stable/c/2b96b4a5d9443ca4cad58b0040be455803c05a42"],"weaknesses":[],"ingestedAt":"2026-10-29T20:06:33.064Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2023/53xxx/CVE-2023-53100.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2023-53100","state":"PUBLISHED","datePublished":"2025-05-02T15:55:43.113Z","dateUpdated":"2026-10-15T21:41:26.510Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-05-02T15:51:43.553Z"},"containers":{"cna":{"title":"ext4: fix WARNING in ext4_update_inline_data","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: fix WARNING in ext4_update_inline_data\n\nSyzbot found the following issue:\nEXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 without journal. Quota mode: none.\nfscrypt: AES-256-CTS-CBC using implementation \"cts-cbc-aes-aesni\"\nfscrypt: AES-256-XTS using implementation \"xts-aes-aesni\"\n------------[ cut here ]------------\nWARNING: CPU: 0 PID: 5071 at mm/page_alloc.c:5525 __alloc_pages+0x30a/0x560 mm/page_alloc.c:5525\nModules linked in:\nCPU: 1 PID: 5071 Comm: syz-executor263 Not tainted 6.2.0-rc1-syzkaller #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022\nRIP: 0010:__alloc_pages+0x30a/0x560 mm/page_alloc.c:5525\nRSP: 0018:ffffc90003c2f1c0 EFLAGS: 00010246\nRAX: ffffc90003c2f220 RBX: 0000000000000014 RCX: 0000000000000000\nRDX: 0000000000000028 RSI: 0000000000000000 RDI: ffffc90003c2f248\nRBP: ffffc90003c2f2d8 R08: dffffc0000000000 R09: ffffc90003c2f220\nR10: fffff52000785e49 R11: 1ffff92000785e44 R12: 0000000000040d40\nR13: 1ffff92000785e40 R14: dffffc0000000000 R15: 1ffff92000785e3c\nFS:  0000555556c0d300(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007f95d5e04138 CR3: 00000000793aa000 CR4: 00000000003506f0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n <TASK>\n __alloc_pages_node include/linux/gfp.h:237 [inline]\n alloc_pages_node include/linux/gfp.h:260 [inline]\n __kmalloc_large_node+0x95/0x1e0 mm/slab_common.c:1113\n __do_kmalloc_node mm/slab_common.c:956 [inline]\n __kmalloc+0xfe/0x190 mm/slab_common.c:981\n kmalloc include/linux/slab.h:584 [inline]\n kzalloc include/linux/slab.h:720 [inline]\n ext4_update_inline_data+0x236/0x6b0 fs/ext4/inline.c:346\n ext4_update_inline_dir fs/ext4/inline.c:1115 [inline]\n ext4_try_add_inline_entry+0x328/0x990 fs/ext4/inline.c:1307\n ext4_add_entry+0x5a4/0xeb0 fs/ext4/namei.c:2385\n ext4_add_nondir+0x96/0x260 fs/ext4/namei.c:2772\n ext4_create+0x36c/0x560 fs/ext4/namei.c:2817\n lookup_open fs/namei.c:3413 [inline]\n open_last_lookups fs/namei.c:3481 [inline]\n path_openat+0x12ac/0x2dd0 fs/namei.c:3711\n do_filp_open+0x264/0x4f0 fs/namei.c:3741\n do_sys_openat2+0x124/0x4e0 fs/open.c:1310\n do_sys_open fs/open.c:1326 [inline]\n __do_sys_openat fs/open.c:1342 [inline]\n __se_sys_openat fs/open.c:1337 [inline]\n __x64_sys_openat+0x243/0x290 fs/open.c:1337\n do_syscall_x64 arch/x86/entry/common.c:50 [inline]\n do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80\n entry_SYSCALL_64_after_hwframe+0x63/0xcd\n\nAbove issue happens as follows:\next4_iget\n   ext4_find_inline_data_nolock ->i_inline_off=164 i_inline_size=60\next4_try_add_inline_entry\n   __ext4_mark_inode_dirty\n      ext4_expand_extra_isize_ea ->i_extra_isize=32 s_want_extra_isize=44\n         ext4_xattr_shift_entries\n\t ->after shift i_inline_off is incorrect, actually is change to 176\next4_try_add_inline_entry\n  ext4_update_inline_dir\n    get_max_inline_xattr_value_size\n      if (EXT4_I(inode)->i_inline_off)\n\tentry = (struct ext4_xattr_entry *)((void *)raw_inode +\n\t\t\tEXT4_I(inode)->i_inline_off);\n        free += EXT4_XATTR_SIZE(le32_to_cpu(entry->e_value_size));\n\t->As entry is incorrect, then 'free' may be negative\n   ext4_update_inline_data\n      value = kzalloc(len, GFP_NOFS);\n      -> len is unsigned int, maybe very large, then trigger warning when\n         'kzalloc()'\n\nTo resolve the above issue we need to update 'i_inline_off' after\n'ext4_xattr_shift_entries()'.  We do not need to set\nEXT4_STATE_MAY_INLINE_DATA flag here, since ext4_mark_inode_dirty()\nalready sets this flag if needed.  Setting EXT4_STATE_MAY_INLINE_DATA\nwhen it is needed may trigger a BUG_ON in ext4_writepages()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"67cf5b09a46f72e048501b84996f2f77bc42e947","status":"affected","lessThan":"c5aa102b433b1890e1ccaa40c06826c77dda1665","versionType":"git"},{"version":"67cf5b09a46f72e048501b84996f2f77bc42e947","status":"affected","lessThan":"39c5df2ca544368b44b59d0f6d80131e90763371","versionType":"git"},{"version":"67cf5b09a46f72e048501b84996f2f77bc42e947","status":"affected","lessThan":"74d775083e9f3d9dadf9e3b5f3e0028d1ad0bd5c","versionType":"git"},{"version":"67cf5b09a46f72e048501b84996f2f77bc42e947","status":"affected","lessThan":"a9bd94f67b27739bbe8583c52256502bd4cc7e83","versionType":"git"},{"version":"67cf5b09a46f72e048501b84996f2f77bc42e947","status":"affected","lessThan":"ca500cf2eceb5a8e93bf71ab97b5f7a18ecabce2","versionType":"git"},{"version":"67cf5b09a46f72e048501b84996f2f77bc42e947","status":"affected","lessThan":"35161cec76772f74526f5886ad4082ec48511d5c","versionType":"git"},{"version":"67cf5b09a46f72e048501b84996f2f77bc42e947","status":"affected","lessThan":"92eee6a82a9a6f9f83559e17a2b6b935e1a5cd25","versionType":"git"},{"version":"67cf5b09a46f72e048501b84996f2f77bc42e947","status":"affected","lessThan":"2b96b4a5d9443ca4cad58b0040be455803c05a42","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ext4/xattr.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.8","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.8","versionType":"semver"},{"version":"4.14.310","status":"unaffected","lessThanOrEqual":"4.14.*","versionType":"semver"},{"version":"4.19.278","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.237","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.175","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.103","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.20","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.2.7","status":"unaffected","lessThanOrEqual":"6.2.*","versionType":"semver"},{"version":"6.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ext4/xattr.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/c5aa102b433b1890e1ccaa40c06826c77dda1665"},{"url":"https://git.kernel.org/stable/c/39c5df2ca544368b44b59d0f6d80131e90763371"},{"url":"https://git.kernel.org/stable/c/74d775083e9f3d9dadf9e3b5f3e0028d1ad0bd5c"},{"url":"https://git.kernel.org/stable/c/a9bd94f67b27739bbe8583c52256502bd4cc7e83"},{"url":"https://git.kernel.org/stable/c/ca500cf2eceb5a8e93bf71ab97b5f7a18ecabce2"},{"url":"https://git.kernel.org/stable/c/35161cec76772f74526f5886ad4082ec48511d5c"},{"url":"https://git.kernel.org/stable/c/92eee6a82a9a6f9f83559e17a2b6b935e1a5cd25"},{"url":"https://git.kernel.org/stable/c/2b96b4a5d9443ca4cad58b0040be455803c05a42"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The bug is reached via local VFS syscalls (openat/create → ext4_try_add_inline_entry / readdir → inline data helpers) on a mounted ext4 filesystem, not via any network or adjacent-link protocol path.\nAC:L - An attacker who can create files in an inline_data directory whose inode still needs extra-isize expansion (common after kernel upgrades, or forced via debug_want_extra_isize) can reliably trigger the stale i_inline_off path; no attacker-uncontrollable race is required.\nPR:L - On an already-mounted ext4 volume (e.g. Android userdata or /home) the trigger is ordinary unprivileged file creation/readdir with write access; unlike SWAP_BOOT-style paths, no init-namespace CAP_SYS_ADMIN is required on this entry point.\nUI:N - The attacker performs the create/readdir operations themselves on a filesystem that is already mounted in the worst reasonable deployment; no separate victim action is required.\nS:U - Impact remains within the host kernel's ext4/VFS authority (local memory corruption / DoS); there is no VM escape, IOMMU bypass, or other cross-authority boundary crossing.\nC:H - Stale i_inline_off causes ext4_read_inline_data to treat attacker-influenced inode bytes as e_value_offs and memcpy from IFIRST+offs with no bounds check, yielding an out-of-bounds kernel read into directory buffers.\nI:H - The same stale offset is consumed by ext4_get_inline_xattr_pos → ext4_add_dirent_to_inline, which writes directory entries to an unchecked IFIRST+e_value_offs destination—an out-of-bounds kernel write exploitable for corruption/control-flow hijack.\nA:H - The demonstrated path computes a huge unsigned kzalloc length and hits WARN_ON_ONCE in __alloc_pages (panic_on_warn / oops class), and the OOB inline-data paths can likewise crash the kernel."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T09:12:46.679Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"4.14.310"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"4.19.278"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"5.4.237"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"5.10.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"5.15.103"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"6.1.20"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"6.2.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.8","versionEndExcluding":"6.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2023-53100","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-15T21:33:45.365692Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-15T21:41:26.510Z"}}]}}}