Description
In the Linux kernel, the following vulnerability has been resolved: NFSv4/flexfiles: reject zero filehandle version count ff_layout_alloc_lseg() decodes the filehandle-version array count from the flexfiles layout body. The value is used as the count for kzalloc_objs(), and the current code only rejects NULL. A zero count yields ZERO_SIZE_PTR, which can be stored in dss_info->fh_versions even though later flexfiles paths assume that at least one filehandle version exists. Reject fh_count == 0 before the allocation, matching the existing zero version_count validation in the flexfiles GETDEVICEINFO parser. A QEMU/KASAN run with a malformed flexfiles layout hit: KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] RIP: 0010:ff_layout_encode_ff_layoutupdate.isra.0+0x15f/0x750 ff_layout_encode_layoutreturn+0x683/0x970 nfs4_xdr_enc_layoutreturn+0x278/0x3a0 Kernel panic - not syncing: Fatal exception The patched kernel rejects the malformed layout without KASAN/oops/panic, and a valid fh_count=1 regression still opens, reads, and unmounts cleanly.
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
d67ae825a59d639e4d8b82413af84d854617a87e to < 9033591535c066726f5b505126ccb4068b98fa4faffectedd67ae825a59d639e4d8b82413af84d854617a87e to < 18cc6d57a14fa65ab2a2b52279f549041c4bc9cfaffectedd67ae825a59d639e4d8b82413af84d854617a87e to < be7829715e341b42846437dd9e721005db59f0ccaffectedd67ae825a59d639e4d8b82413af84d854617a87e to < eeabb9020721db6bc132e68eeae380b8d4fb4b04affectedd67ae825a59d639e4d8b82413af84d854617a87e to < 7779c85028a0676fb190cde4f0c540f4f8e97761affectedd67ae825a59d639e4d8b82413af84d854617a87e to < d8c90c7cc061265d5f2813a1f5c82ef2f4707e67affectedd67ae825a59d639e4d8b82413af84d854617a87e to < 2131ed64b767ffa8bcdb3677d90f3964e39aabc8affectedd67ae825a59d639e4d8b82413af84d854617a87e to < 2c6bb3c40bc24f6aa8dfbe6fe98c3ad6389203f2affected
Linux Linux
Default version status: affected
4.0affected0 to < 4.0unaffected5.10.261 to ≤ 5.10.*unaffected5.15.212 to ≤ 5.15.*unaffected6.1.178 to ≤ 6.1.*unaffected6.6.145 to ≤ 6.6.*unaffected6.12.96 to ≤ 6.12.*unaffected6.18.38 to ≤ 6.18.*unaffected7.1.3 to ≤ 7.1.*unaffected7.2 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/9033591535c066726f5b505126ccb4068b98fa4f ↗
- https://git.kernel.org/stable/c/18cc6d57a14fa65ab2a2b52279f549041c4bc9cf ↗
- https://git.kernel.org/stable/c/be7829715e341b42846437dd9e721005db59f0cc ↗
- https://git.kernel.org/stable/c/eeabb9020721db6bc132e68eeae380b8d4fb4b04 ↗
- https://git.kernel.org/stable/c/7779c85028a0676fb190cde4f0c540f4f8e97761 ↗
- https://git.kernel.org/stable/c/d8c90c7cc061265d5f2813a1f5c82ef2f4707e67 ↗
- https://git.kernel.org/stable/c/2131ed64b767ffa8bcdb3677d90f3964e39aabc8 ↗
- https://git.kernel.org/stable/c/2c6bb3c40bc24f6aa8dfbe6fe98c3ad6389203f2 ↗