{"id":"CVE-2026-43245","state":"PUBLISHED","title":"ntfs: ->d_compare() must not block","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nntfs: ->d_compare() must not block\n\n... so don't use __getname() there.  Switch it (and ntfs_d_hash(), while\nwe are at it) to kmalloc(PATH_MAX, GFP_NOWAIT).  Yes, ntfs_d_hash()\nalmost certainly can do with smaller allocations, but let ntfs folks\ndeal with that - keep the allocation size as-is for now.\n\nStop abusing names_cachep in ntfs, period - various uses of that thing\nin there have nothing to do with pathnames; just use k[mz]alloc() and\nbe done with that.  For now let's keep sizes as-in, but AFAICS none of\nthe users actually want PATH_MAX.","publishedAt":"2026-05-06T11:28:37.602Z","updatedAt":"2026-08-05T12:26:50.510Z","severity":{"score":7.5,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"a3a956c78efaa202b1d75190136671cf6e87bfbe","status":"affected","lessThan":"02ecc0978c459fd90bb24b2a946dd16d43e68fe5","versionType":"git"},{"version":"a3a956c78efaa202b1d75190136671cf6e87bfbe","status":"affected","lessThan":"1be7ca86ce1794d966fda5d82181bc978b150fbc","versionType":"git"},{"version":"a3a956c78efaa202b1d75190136671cf6e87bfbe","status":"affected","lessThan":"142c444a395f4d26055c8a4473e228bb86283f1e","versionType":"git"},{"version":"a3a956c78efaa202b1d75190136671cf6e87bfbe","status":"affected","lessThan":"fb4b1f969ba01fa1d4088467a02fc1e5f0806710","versionType":"git"},{"version":"a3a956c78efaa202b1d75190136671cf6e87bfbe","status":"affected","lessThan":"ca2a04e84af79596e5cd9cfe697d5122ec39c8ce","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ntfs3/dir.c","fs/ntfs3/fsntfs.c","fs/ntfs3/inode.c","fs/ntfs3/namei.c","fs/ntfs3/xattr.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.2","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.2","versionType":"semver"},{"version":"6.6.141","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.91","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.16","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.6","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ntfs3/dir.c","fs/ntfs3/fsntfs.c","fs/ntfs3/inode.c","fs/ntfs3/namei.c","fs/ntfs3/xattr.c"]}],"references":["https://git.kernel.org/stable/c/02ecc0978c459fd90bb24b2a946dd16d43e68fe5","https://git.kernel.org/stable/c/1be7ca86ce1794d966fda5d82181bc978b150fbc","https://git.kernel.org/stable/c/142c444a395f4d26055c8a4473e228bb86283f1e","https://git.kernel.org/stable/c/fb4b1f969ba01fa1d4088467a02fc1e5f0806710","https://git.kernel.org/stable/c/ca2a04e84af79596e5cd9cfe697d5122ec39c8ce"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:57.932Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/43xxx/CVE-2026-43245.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-43245","state":"PUBLISHED","datePublished":"2026-05-06T11:28:37.602Z","dateUpdated":"2026-08-05T12:26:50.510Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-05-01T14:12:55.996Z"},"containers":{"cna":{"title":"ntfs: ->d_compare() must not block","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nntfs: ->d_compare() must not block\n\n... so don't use __getname() there.  Switch it (and ntfs_d_hash(), while\nwe are at it) to kmalloc(PATH_MAX, GFP_NOWAIT).  Yes, ntfs_d_hash()\nalmost certainly can do with smaller allocations, but let ntfs folks\ndeal with that - keep the allocation size as-is for now.\n\nStop abusing names_cachep in ntfs, period - various uses of that thing\nin there have nothing to do with pathnames; just use k[mz]alloc() and\nbe done with that.  For now let's keep sizes as-in, but AFAICS none of\nthe users actually want PATH_MAX."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"a3a956c78efaa202b1d75190136671cf6e87bfbe","status":"affected","lessThan":"02ecc0978c459fd90bb24b2a946dd16d43e68fe5","versionType":"git"},{"version":"a3a956c78efaa202b1d75190136671cf6e87bfbe","status":"affected","lessThan":"1be7ca86ce1794d966fda5d82181bc978b150fbc","versionType":"git"},{"version":"a3a956c78efaa202b1d75190136671cf6e87bfbe","status":"affected","lessThan":"142c444a395f4d26055c8a4473e228bb86283f1e","versionType":"git"},{"version":"a3a956c78efaa202b1d75190136671cf6e87bfbe","status":"affected","lessThan":"fb4b1f969ba01fa1d4088467a02fc1e5f0806710","versionType":"git"},{"version":"a3a956c78efaa202b1d75190136671cf6e87bfbe","status":"affected","lessThan":"ca2a04e84af79596e5cd9cfe697d5122ec39c8ce","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ntfs3/dir.c","fs/ntfs3/fsntfs.c","fs/ntfs3/inode.c","fs/ntfs3/namei.c","fs/ntfs3/xattr.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.2","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.2","versionType":"semver"},{"version":"6.6.141","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.91","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.16","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.6","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/ntfs3/dir.c","fs/ntfs3/fsntfs.c","fs/ntfs3/inode.c","fs/ntfs3/namei.c","fs/ntfs3/xattr.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/02ecc0978c459fd90bb24b2a946dd16d43e68fe5"},{"url":"https://git.kernel.org/stable/c/1be7ca86ce1794d966fda5d82181bc978b150fbc"},{"url":"https://git.kernel.org/stable/c/142c444a395f4d26055c8a4473e228bb86283f1e"},{"url":"https://git.kernel.org/stable/c/fb4b1f969ba01fa1d4088467a02fc1e5f0806710"},{"url":"https://git.kernel.org/stable/c/ca2a04e84af79596e5cd9cfe697d5122ec39c8ce"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","baseScore":7.5,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:N - The vulnerable `ntfs_d_compare()` is reached during ordinary VFS pathname lookup on an ntfs3 `nocase` mount; a reasonable high-impact deployment is an ntfs3 volume exported by in-kernel NFS/SMB, where remote client-supplied pathnames drive that lookup. Local syscalls can also trigger it, but the network-file-server path is the higher defensible attack vector.\nAC:L - The attacker controls the lookup pathname and can repeatedly exercise non-ASCII/case-insensitive comparisons that enter the slow path. The bug is a deterministic forbidden blocking allocation in a non-blocking VFS callback, not a race requiring conditions outside attacker influence.\nPR:N - In the network-export scenario, a remote client can issue lookup/open/stat style requests against an exported share without having local privileges on the kernel host. If authentication is configured it may raise environmental requirements, but an unauthenticated or guest-accessible export is reasonable.\nUI:N - No victim user action is required once the vulnerable ntfs3 filesystem is mounted/exported. The attacker triggers the path lookup directly by requesting crafted pathnames.\nS:U - The impact remains within the kernel/filesystem security authority. This is not a VM escape, IOMMU bypass, or cross-scope boundary violation.\nC:N - The bug is sleeping/blocking allocation in `d_compare()`, not a memory disclosure primitive. I found no out-of-bounds read, use-after-free, or arbitrary read behavior in the fixed path.\nI:N - The vulnerable code does not corrupt attacker-controlled memory or provide a write primitive. It violates VFS atomic/RCU locking rules but does not directly modify data or enable control-flow hijacking.\nA:H - Calling `__getname()`/`GFP_KERNEL` from `d_compare()` can sleep in RCU/non-blocking lookup context, causing RCU stalls, soft lockups, warnings/oopses, or deadlock under pressure. Repeated attacker-triggered lookups can therefore deny service to the kernel."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:26:50.510Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.6.141"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.12.91"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.18.16"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"6.19.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.2","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}