{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-89602","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-09-11T19:38:34.732Z","datePublished":"2026-09-11T19:45:05.783Z","dateUpdated":"2026-09-21T13:14:33.615Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-09-21T13:14:33.615Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nerofs: skip sufficiently large global buffers when resizing\n\nz_erofs_gbuf_nrpages is advanced only after every global buffer has been\ngrown. If a resize fails after some buffers were enlarged, a retry\nrevisits those enlarged buffers.\n\nRetrying the same size then returns -ENOMEM because alloc_pages_bulk()\nhas no pages to add and the unchanged return value is treated as a\nfailure. Retrying an intermediate size allocates a temporary pointer\narray smaller than gbuf->nrpages and copies more existing pointers than\nthe array can hold.\n\nSkip buffers that already satisfy the request. Once all remaining\nbuffers have caught up, advancing z_erofs_gbuf_nrpages again describes\nthe guaranteed minimum size across the pool."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - z_erofs_gbuf_growsize() runs only during a local EROFS mount (erofs_fc_get_tree → erofs_fc_fill_super → erofs_read_superblock → z_erofs_parse_cfgs → z_erofs_load_lz4_config) of a block, loop, or file-backed image. The LZ4 max_pclusterblks field is not parsed from a network protocol, so the vector is Local.\nAC:L - The attacker picks max_pclusterblks on two images (a large grow, then a strictly smaller size). After GFP_KERNEL alloc_pages_bulk()/vmap fails mid-loop, some per-CPU gbufs stay enlarged while z_erofs_gbuf_nrpages does not; the next intermediate mount then copies gbuf->nrpages pointers into a smaller tmp_pages array with no race. A max-size image plus memory pressure makes that partial failure attacker-inducible.\nPR:N - Crafting and supplying the malicious EROFS images needs no account or capability on the target. erofs_fs_type lacks FS_USERNS_MOUNT, so the CAP_SYS_ADMIN mount is done by a victim, automounter, or container runtime (OCI/Nydus/Android image handling), matching other crafted-image EROFS CVEs.\nUI:R - mount_capable() requires CAP_SYS_ADMIN in the initial user namespace because EROFS is not FS_USERNS_MOUNT. A separate user, automounter, or container runtime must mount the attacker-supplied images before z_erofs_gbuf_growsize() runs.\nS:U - The heap overflow corrupts kmalloc objects inside the host kernel. That is standard kernel memory corruption within one security authority, not a VM escape, IOMMU bypass, or other cross-boundary impact.\nC:H - The copy loop writes a nearly page-count-sized run of struct page * values past the kmalloc tmp_pages array (up to hundreds of pointers when max_pclusterblks is 256). That slab corruption can be turned into an arbitrary-read primitive against adjacent objects, so confidentiality impact is High.\nI:H - This is a kernel heap out-of-bounds write whose length is chosen by the two image sizes, smashing adjacent slab objects with kernel page pointers. Out-of-bounds writes are exploitable for arbitrary write and control-flow hijacking, so integrity impact is High.\nA:H - Overwriting adjacent kmalloc metadata and objects causes a kernel oops or panic. Independently, retrying the same size after a partial grow treats a full tmp_pages array as -ENOMEM and leaves the pool stuck, so later EROFS mounts fail until reboot."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/erofs/zutil.c"],"versions":[{"version":"d6db47e571dcaecaeaafa8840d00ae849ae3907b","lessThan":"3fbdd15d5830f52661eb78be95058d101cb0c2cb","status":"affected","versionType":"git"},{"version":"d6db47e571dcaecaeaafa8840d00ae849ae3907b","lessThan":"7267557ce98ccd07faaf3bc86382448950cc4ff6","status":"affected","versionType":"git"},{"version":"d6db47e571dcaecaeaafa8840d00ae849ae3907b","lessThan":"7f4a89d4f0d6acaf4b756c31de48f2109a257b70","status":"affected","versionType":"git"},{"version":"d6db47e571dcaecaeaafa8840d00ae849ae3907b","lessThan":"a7d097cf01301c5da37927c8f26123d006f0fd8a","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/erofs/zutil.c"],"versions":[{"version":"6.10","status":"affected"},{"version":"0","lessThan":"6.10","status":"unaffected","versionType":"semver"},{"version":"6.12.111","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.51","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.2.4","lessThanOrEqual":"7.2.*","status":"unaffected","versionType":"semver"},{"version":"7.3-rc1","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.10","versionEndExcluding":"6.12.111"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.10","versionEndExcluding":"6.18.51"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.10","versionEndExcluding":"7.2.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.10","versionEndExcluding":"7.3-rc1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/3fbdd15d5830f52661eb78be95058d101cb0c2cb"},{"url":"https://git.kernel.org/stable/c/7267557ce98ccd07faaf3bc86382448950cc4ff6"},{"url":"https://git.kernel.org/stable/c/7f4a89d4f0d6acaf4b756c31de48f2109a257b70"},{"url":"https://git.kernel.org/stable/c/a7d097cf01301c5da37927c8f26123d006f0fd8a"}],"title":"erofs: skip sufficiently large global buffers when resizing","x_generator":{"engine":"bippy-1.2.0"}}}}