Evidence used
- No CISA KEV confirmation is currently recorded.
- Exploitation requires an existing local or physical foothold with privileges.
- EPSS is 0.21% for the current model date.
BlackTreeCVE IntelligenceFull vulnerability report · 2025
CVE-2023-53100High confidence
ext4: fix WARNING in ext4_update_inline_data
Linux · Linux
7.8HighCVSS 3.1
Patch only the product branches with a verified fix
Fix availability varies by productHigh technical severity; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 2 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
R
Open reassessment dashboard →Operational reassessment
Published severity in operational context
Published severityHigh→Operational priority:Medium, lowered one band.downgradedsince 5 Aug 2026
Compensating controls
- Validate the affected product branch and deploy the verified fixed release.
- Restrict local access and enforce least privilege on affected hosts.
- Monitor vendor guidance and exploitation sources for a material change.
Verification
- Confirm that the asset runs Linux Linux and falls inside the recorded affected range.
- Verify the installed build against the product-specific fixed version after deployment.
- Validate exposure, authentication requirements and compensating controls in the actual environment.
- Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Remediation availability differs by product scope
Verified remediation exists for at least one product or source, but 2 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
- Canonical Ubuntu Security: 2 affected package states with no published fix
Distribution package intelligence
6 package statesRelease-specific package status
Debian, ubuntu findings are scoped to the named distribution, release and source package. An absent finding does not mean a package is unaffected.
Package result overrides the generic status
BlackTree has verified remediation for at least one product or source, but the relevant distribution still reports no fixed package for 2 affected package states shown here. Treat those rows as affected with no fix until that distribution publishes a fixed version.
Repository candidate not checked
A published vendor fix does not prove that a matching update is enabled and installable on a particular asset. Confirm the local package candidate before scheduling remediation.
| Distribution release | Source package | Vendor state | Fixed version | Evidence |
|---|---|---|---|---|
| Debian trixietrixie · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 6.1.20-1 | Debian Security Tracker ↗Source updated 6 Oct 2026 |
| Debian bookwormbookworm · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 6.1.20-1 | Debian Security Tracker ↗Source updated 6 Oct 2026 |
| Debian forkyforky · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 6.1.20-1 | Debian Security Tracker ↗Source updated 6 Oct 2026 |
| Debian sidsid · source | linux | Vendor fix publishedDebian records a fixed source-package version for this release. | 6.1.20-1 | Debian Security Tracker ↗Source updated 6 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-raspi-realtime | Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition. | Not published in this feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
| Ubuntu 24.04 LTSnoble · standard archive | linux-realtime | Affected, no fix publishedCanonical OVAL identifies this running kernel flavour as affected and does not publish a fixed package version in this definition. | Not published in this feed | Canonical Ubuntu Security ↗Source updated 5 Oct 2026 |
High technical severity; prioritise exposed affected systems while verifying vendor guidance. Verified remediation exists for at least one product or source, but 2 structured product or package states remain unresolved. Apply remediation only to the exact product branch confirmed by its source.
Fix availability varies by product01
What, why and how
In the Linux kernel, the following vulnerability has been resolved: ext4: fix WARNING in ext4_update_inline_data Syzbot found the following issue: EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 without journal. Quota mode: none. fscrypt: AES-256-CTS-CBC using implementation "cts-cbc-aes-aesni" fscrypt: AES-256-XTS using implementation "xts-aes-aesni" ------------[ cut here ]------------ WARNING: CPU: 0 PID: 5071 at mm/page_alloc.c:5525 __alloc_pages+0x30a/0x560 mm/page_alloc.c:5525 Modules linked in: CPU: 1 PID: 5071 Comm: syz-executor263 Not tainted 6.2.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 RIP: 0010:__alloc_pages+0x30a/0x560 mm/page_alloc.c:5525 RSP: 0018:ffffc90003c2f1c0 EFLAGS: 00010246 RAX: ffffc90003c2f220 RBX: 0000000000000014 RCX: 0000000000000000 RDX: 0000000000000028 RSI: 0000000000000000 RDI: ffffc90003c2f248 RBP: ffffc90003c2f2d8 R08: dffffc0000000000 R09: ffffc90003c2f220 R10: fffff52000785e49 R11: 1ffff92000785e44 R12: 0000000000040d40 R13: 1ffff92000785e40 R14: dffffc0000000000 R15: 1ffff92000785e3c FS: 0000555556c0d300(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f95d5e04138 CR3: 00000000793aa000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __alloc_pages_node include/linux/gfp.h:237 [inline] alloc_pages_node include/linux/gfp.h:260 [inline] __kmalloc_large_node+0x95/0x1e0 mm/slab_common.c:1113 __do_kmalloc_node mm/slab_common.c:956 [inline] __kmalloc+0xfe/0x190 mm/slab_common.c:981 kmalloc include/linux/slab.h:584 [inline] kzalloc include/linux/slab.h:720 [inline] ext4_update_inline_data+0x236/0x6b0 fs/ext4/inline.c:346 ext4_update_inline_dir fs/ext4/inline.c:1115 [inline] ext4_try_add_inline_entry+0x328/0x990 fs/ext4/inline.c:1307 ext4_add_entry+0x5a4/0xeb0 fs/ext4/namei.c:2385 ext4_add_nondir+0x96/0x260 fs/ext4/namei.c:2772 ext4_create+0x36c/0x560 fs/ext4/namei.c:2817 lookup_open fs/namei.c:3413 [inline] open_last_lookups fs/namei.c:3481 [inline] path_openat+0x12ac/0x2dd0 fs/namei.c:3711 do_filp_open+0x264/0x4f0 fs/namei.c:3741 do_sys_openat2+0x124/0x4e0 fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_sys_openat fs/open.c:1342 [inline] __se_sys_openat fs/open.c:1337 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1337 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Above issue happens as follows: ext4_iget ext4_find_inline_data_nolock ->i_inline_off=164 i_inline_size=60 ext4_try_add_inline_entry __ext4_mark_inode_dirty ext4_expand_extra_isize_ea ->i_extra_isize=32 s_want_extra_isize=44 ext4_xattr_shift_entries ->after shift i_inline_off is incorrect, actually is change to 176 ext4_try_add_inline_entry ext4_update_inline_dir get_max_inline_xattr_value_size if (EXT4_I(inode)->i_inline_off) entry = (struct ext4_xattr_entry *)((void *)raw_inode + EXT4_I(inode)->i_inline_off); free += EXT4_XATTR_SIZE(le32_to_cpu(entry->e_value_size)); ->As entry is incorrect, then 'free' may be negative ext4_update_inline_data value = kzalloc(len, GFP_NOFS); -> len is unsigned int, maybe very large, then trigger warning when 'kzalloc()' To resolve the above issue we need to update 'i_inline_off' after 'ext4_xattr_shift_entries()'. We do not need to set EXT4_STATE_MAY_INLINE_DATA flag here, since ext4_mark_inode_dirty() already sets this flag if needed. Setting EXT4_STATE_MAY_INLINE_DATA when it is needed may trigger a BUG_ON in ext4_writepages().
What
In the Linux kernel, the following vulnerability has been resolved: ext4: fix WARNING in ext4_update_inline_data Syzbot found the following issue: EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 without journal. Quota mode: none. fscrypt: AES-256-CTS-CBC using implementation "cts-cbc-aes-aesni" fscrypt: AES-256-XTS using implementation "xts-aes-aesni" ------------[ cut here ]------------ WARNING: CPU: 0 PID: 5071 at mm/page_alloc.c:5525 __alloc_pages+0x30a/0x560 mm/page_alloc.c:5525 Modules linked in: CPU: 1 PID: 5071 Comm: syz-executor263 Not tainted 6.2.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 RIP: 0010:__alloc_pages+0x30a/0x560 mm/page_alloc.c:5525 RSP: 0018:ffffc90003c2f1c0 EFLAGS: 00010246 RAX: ffffc90003c2f220 RBX: 0000000000000014 RCX: 0000000000000000 RDX: 0000000000000028 RSI: 0000000000000000 RDI: ffffc90003c2f248 RBP: ffffc90003c2f2d8 R08: dffffc0000000000 R09: ffffc90003c2f220 R10: fffff52000785e49 R11: 1ffff92000785e44 R12: 0000000000040d40 R13: 1ffff92000785e40 R14: dffffc0000000000 R15: 1ffff92000785e3c FS: 0000555556c0d300(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f95d5e04138 CR3: 00000000793aa000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __alloc_pages_node include/linux/gfp.h:237 [inline] alloc_pages_node include/linux/gfp.h:260 [inline] __kmalloc_large_node+0x95/0x1e0 mm/slab_common.c:1113 __do_kmalloc_node mm/slab_common.c:956 [inline] __kmalloc+0xfe/0x190 mm/slab_common.c:981 kmalloc include/linux/slab.h:584 [inline] kzalloc include/linux/slab.h:720 [inline] ext4_update_inline_data+0x236/0x6b0 fs/ext4/inline.c:346 ext4_update_inline_dir fs/ext4/inline.c:1115 [inline] ext4_try_add_inline_entry+0x328/0x990 fs/ext4/inline.c:1307 ext4_add_entry+0x5a4/0xeb0 fs/ext4/namei.c:2385 ext4_add_nondir+0x96/0x260 fs/ext4/namei.c:2772 ext4_create+0x36c/0x560 fs/ext4/namei.c:2817 lookup_open fs/namei.c:3413 [inline] open_last_lookups fs/namei.c:3481 [inline] path_openat+0x12ac/0x2dd0 fs/namei.c:3711 do_filp_open+0x264/0x4f0 fs/namei.c:3741 do_sys_openat2+0x124/0x4e0 fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_sys_openat fs/open.c:1342 [inline] __se_sys_openat fs/open.c:1337 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1337 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Above issue happens as follows: ext4_iget ext4_find_inline_data_nolock ->i_inline_off=164 i_inline_size=60 ext4_try_add_inline_entry __ext4_mark_inode_dirty ext4_expand_extra_isize_ea ->i_extra_isize=32 s_want_extra_isize=44 ext4_xattr_shift_entries ->after shift i_inline_off is incorrect, actually is change to 176 ext4_try_add_inline_entry ext4_update_inline_dir get_max_inline_xattr_value_size if (EXT4_I(inode)->i_inline_off) entry = (struct ext4_xattr_entry *)((void *)raw_inode + EXT4_I(inode)->i_inline_off); free += EXT4_XATTR_SIZE(le32_to_cpu(entry->e_value_size)); ->As entry is incorrect, then 'free' may be negative ext4_update_inline_data value = kzalloc(len, GFP_NOFS); -> len is unsigned int, maybe very large, then trigger warning when 'kzalloc()' To resolve the above issue we need to update 'i_inline_off' after 'ext4_xattr_shift_entries()'. We do not need to set EXT4_STATE_MAY_INLINE_DATA flag here, since ext4_mark_inode_dirty() already sets this flag if needed. Setting EXT4_STATE_MAY_INLINE_DATA when it is needed may trigger a BUG_ON in ext4_writepages().
Why
The current structured CVE record identifies a security weakness, but the root cause requires confirmation in the linked vendor material.
How
An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
What
In the Linux kernel, the following vulnerability has been resolved: ext4: fix WARNING in ext4_update_inline_data Syzbot found the following issue: EXT4-fs (loop0): mounted filesystem 00000000-0000-0000-0000-000000000000 without journal. Quota mode: none. fscrypt: AES-256-CTS-CBC using implementation "cts-cbc-aes-aesni" fscrypt: AES-256-XTS using implementation "xts-aes-aesni" ------------[ cut here ]------------ WARNING: CPU: 0 PID: 5071 at mm/page_alloc.c:5525 __alloc_pages+0x30a/0x560 mm/page_alloc.c:5525 Modules linked in: CPU: 1 PID: 5071 Comm: syz-executor263 Not tainted 6.2.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 RIP: 0010:__alloc_pages+0x30a/0x560 mm/page_alloc.c:5525 RSP: 0018:ffffc90003c2f1c0 EFLAGS: 00010246 RAX: ffffc90003c2f220 RBX: 0000000000000014 RCX: 0000000000000000 RDX: 0000000000000028 RSI: 0000000000000000 RDI: ffffc90003c2f248 RBP: ffffc90003c2f2d8 R08: dffffc0000000000 R09: ffffc90003c2f220 R10: fffff52000785e49 R11: 1ffff92000785e44 R12: 0000000000040d40 R13: 1ffff92000785e40 R14: dffffc0000000000 R15: 1ffff92000785e3c FS: 0000555556c0d300(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f95d5e04138 CR3: 00000000793aa000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __alloc_pages_node include/linux/gfp.h:237 [inline] alloc_pages_node include/linux/gfp.h:260 [inline] __kmalloc_large_node+0x95/0x1e0 mm/slab_common.c:1113 __do_kmalloc_node mm/slab_common.c:956 [inline] __kmalloc+0xfe/0x190 mm/slab_common.c:981 kmalloc include/linux/slab.h:584 [inline] kzalloc include/linux/slab.h:720 [inline] ext4_update_inline_data+0x236/0x6b0 fs/ext4/inline.c:346 ext4_update_inline_dir fs/ext4/inline.c:1115 [inline] ext4_try_add_inline_entry+0x328/0x990 fs/ext4/inline.c:1307 ext4_add_entry+0x5a4/0xeb0 fs/ext4/namei.c:2385 ext4_add_nondir+0x96/0x260 fs/ext4/namei.c:2772 ext4_create+0x36c/0x560 fs/ext4/namei.c:2817 lookup_open fs/namei.c:3413 [inline] open_last_lookups fs/namei.c:3481 [inline] path_openat+0x12ac/0x2dd0 fs/namei.c:3711 do_filp_open+0x264/0x4f0 fs/namei.c:3741 do_sys_openat2+0x124/0x4e0 fs/open.c:1310 do_sys_open fs/open.c:1326 [inline] __do_sys_openat fs/open.c:1342 [inline] __se_sys_openat fs/open.c:1337 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1337 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Above issue happens as follows: ext4_iget ext4_find_inline_data_nolock ->i_inline_off=164 i_inline_size=60 ext4_try_add_inline_entry __ext4_mark_inode_dirty ext4_expand_extra_isize_ea ->i_extra_isize=32 s_want_extra_isize=44 ext4_xattr_shift_entries ->after shift i_inline_off is incorrect, actually is change to 176 ext4_try_add_inline_entry ext4_update_inline_dir get_max_inline_xattr_value_size if (EXT4_I(inode)->i_inline_off) entry = (struct ext4_xattr_entry *)((void *)raw_inode + EXT4_I(inode)->i_inline_off); free += EXT4_XATTR_SIZE(le32_to_cpu(entry->e_value_size)); ->As entry is incorrect, then 'free' may be negative ext4_update_inline_data value = kzalloc(len, GFP_NOFS); -> len is unsigned int, maybe very large, then trigger warning when 'kzalloc()' To resolve the above issue we need to update 'i_inline_off' after 'ext4_xattr_shift_entries()'. We do not need to set EXT4_STATE_MAY_INLINE_DATA flag here, since ext4_mark_inode_dirty() already sets this flag if needed. Setting EXT4_STATE_MAY_INLINE_DATA when it is needed may trigger a BUG_ON in ext4_writepages().
Why
The current structured CVE record identifies a security weakness, but the root cause requires confirmation in the linked vendor material.
How
An attacker operating through local access may attempt exploitation with low privileges. If successful, the issue may cause the confidentiality, integrity or availability impact described by the vendor.
02
Exploit reality and attack path
CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.
Observed exploitation No confirmed evidence
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No CISA KEV match was present at the last successful refresh. This means no confirmation from that source, not proof of no exploitation.
Public PoC / exploit material None recorded
?
Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.
- Likely attack path
- local access → vulnerable operation → cause the confidentiality, integrity or availability impact described by the vendor
- Attack surface
- Local
- Privileges required
- Low: a basic authenticated account is required
- User interaction
- None
- Attack complexity
- Low: no specialised conditions are recorded
- Security boundary
- Unchanged: impact remains within the vulnerable component's security authority
- Weakness
?
CWE means Common Weakness Enumeration. - CWE not yet assigned
- CVSS vector
?
CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity. CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HCommon Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVLocalAttack vector: The attacker needs local access to the vulnerable system.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRLowPrivileges required: The attacker needs basic user-level privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.- Post-exploitation / living off the land
- The issue can support a local privilege or sandbox boundary transition; normal system utilities may then be available in the gained context.
03
Patch and workaround
Operational remediation based on structured source evidence.
- Status
?
Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change. - Fix availability varies by product
- Action
- Use the product-specific evidence above. Patch only products with a verified fixed release, and keep every affected or under-investigation state without a matching fix in the remediation queue.
- Workaround
- No verified workaround is recorded. Limit untrusted access and use least privilege until authoritative guidance is available.
04
Evidence and provenance
Published 2 May 2025 · Last source change 5 Aug 2026, 09:12 UTC · CWE not yet assigned
CVE recordCVE.org · 5.2
CVSS sourceCNA
EPSS source FIRST · tracked since 2026-08-14
?
The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.European sourceENISA EUVD · EUVD-2025-13162
Product sourceCNA
Remediation sourceCVE/CNA references
CWE sourceUnavailable
NVD statusNVD modified after enrichment
Missing structured fields: CWE classification. Missing data is not evidence of low risk; review the primary advisory.
Material change intelligence
View recent updates ↗What changed after publication
No material field changes have been recorded since change tracking began. Routine source refreshes and cosmetic edits are intentionally excluded.
CVE published
Fixed release or patch reference recorded
Technical terms and abbreviations used in this report
- CVE
- Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
- CVSS
- Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
- EPSS
- Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
- CWE
- Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
- CNA
- CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
- CISA ADP
- Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
- NVD
- National Vulnerability Database: NIST's enrichment service for CVE records.
- CERT / CSIRT
- A computer security incident response team that publishes warnings or coordinates incident response.
- PoC
- Proof of concept: public material that demonstrates or helps reproduce exploitation.
- CSAF
- Common Security Advisory Framework: a machine-readable format for security advisories.
- LoTL
- Living off the land: abuse of legitimate tools or system functions during an attack.