Description
In the Linux kernel, the following vulnerability has been resolved: efivarfs: Fix slab-out-of-bounds in efivarfs_d_compare Observed on kernel 6.6 (present on master as well): BUG: KASAN: slab-out-of-bounds in memcmp+0x98/0xd0 Call trace: kasan_check_range+0xe8/0x190 __asan_loadN+0x1c/0x28 memcmp+0x98/0xd0 efivarfs_d_compare+0x68/0xd8 __d_lookup_rcu_op_compare+0x178/0x218 __d_lookup_rcu+0x1f8/0x228 d_alloc_parallel+0x150/0x648 lookup_open.isra.0+0x5f0/0x8d0 open_last_lookups+0x264/0x828 path_openat+0x130/0x3f8 do_filp_open+0x114/0x248 do_sys_openat2+0x340/0x3c0 __arm64_sys_openat+0x120/0x1a0 If dentry->d_name.len < EFI_VARIABLE_GUID_LEN , 'guid' can become negative, leadings to oob. The issue can be triggered by parallel lookups using invalid filename: T1 T2 lookup_open ->lookup simple_lookup d_add // invalid dentry is added to hash list lookup_open d_alloc_parallel __d_lookup_rcu __d_lookup_rcu_op_compare hlist_bl_for_each_entry_rcu // invalid dentry can be retrieved ->d_compare efivarfs_d_compare // oob Fix it by checking 'guid' before cmp.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
da27a24383b2b10bf6ebd0db29b325548aafecb4 to < 0f63fbabeaaaaaaf5b742a2f4c1b4590d50bf1f6affectedda27a24383b2b10bf6ebd0db29b325548aafecb4 to < 794399019301944fd6d2e0d7a51b3327e26c410eaffectedda27a24383b2b10bf6ebd0db29b325548aafecb4 to < 568e7761279b99c6daa3002290fd6d8047ddb6d2affectedda27a24383b2b10bf6ebd0db29b325548aafecb4 to < d7f5e35e70507d10cbaff5f9e194ed54c4ee14f7affectedda27a24383b2b10bf6ebd0db29b325548aafecb4 to < 925599eba46045930b850a98ae594d2e3028ac40affectedda27a24383b2b10bf6ebd0db29b325548aafecb4 to < c2925cd6207079c3f4d040d082515db78d63afbfaffectedda27a24383b2b10bf6ebd0db29b325548aafecb4 to < 71581a82f38e5a4d807d71fc1bb59aead80ccf95affectedda27a24383b2b10bf6ebd0db29b325548aafecb4 to < a6358f8cf64850f3f27857b8ed8c1b08cfc4685caffected688289c4b745c018b3449b4b4c5a2030083c8eafaffected3.8.2 to < 3.9affected
Linux Linux
Default version status: affected
3.9affected0 to < 3.9unaffected5.4.298 to ≤ 5.4.*unaffected5.10.242 to ≤ 5.10.*unaffected5.15.191 to ≤ 5.15.*unaffected6.1.150 to ≤ 6.1.*unaffected6.6.104 to ≤ 6.6.*unaffected6.12.45 to ≤ 6.12.*unaffected6.16.5 to ≤ 6.16.*unaffected6.17 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/0f63fbabeaaaaaaf5b742a2f4c1b4590d50bf1f6 ↗
- https://git.kernel.org/stable/c/794399019301944fd6d2e0d7a51b3327e26c410e ↗
- https://git.kernel.org/stable/c/568e7761279b99c6daa3002290fd6d8047ddb6d2 ↗
- https://git.kernel.org/stable/c/d7f5e35e70507d10cbaff5f9e194ed54c4ee14f7 ↗
- https://git.kernel.org/stable/c/925599eba46045930b850a98ae594d2e3028ac40 ↗
- https://git.kernel.org/stable/c/c2925cd6207079c3f4d040d082515db78d63afbf ↗
- https://git.kernel.org/stable/c/71581a82f38e5a4d807d71fc1bb59aead80ccf95 ↗
- https://git.kernel.org/stable/c/a6358f8cf64850f3f27857b8ed8c1b08cfc4685c ↗
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html ↗
- https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html ↗
- https://cert-portal.siemens.com/productcert/html/ssa-032379.html ↗