Description
In the Linux kernel, the following vulnerability has been resolved: mmmremap.c: avoid pointless invalidate_range_start/end on mremap(old_size=0) If an mremap() syscall with old_size=0 ends up in move_page_tables(), it will call invalidate_range_start()/invalidate_range_end() unnecessarily, i.e. with an empty range. This causes a WARN in KVM's mmu_notifier. In the past, empty ranges have been diagnosed to be off-by-one bugs, hence the WARNing. Given the low (so far) number of unique reports, the benefits of detecting more buggy callers seem to outweigh the cost of having to fix cases such as this one, where userspace is doing something silly. In this particular case, an early return from move_page_tables() is enough to fix the issue.
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
7b6efc2bc4f19952b25ebf9b236e5ac43cd386c2 to < a05540f3903bd8295e8c4cd90dd3d416239a115baffected7b6efc2bc4f19952b25ebf9b236e5ac43cd386c2 to < eeaf28e2a0128147d687237e59d5407ee1b14693affected7b6efc2bc4f19952b25ebf9b236e5ac43cd386c2 to < e2c328c2a8f9de8b761bd4025b66c63120c55761affected7b6efc2bc4f19952b25ebf9b236e5ac43cd386c2 to < c19d8de4e682ec4b0ea2b04a832cd8cc0be3bb31affected7b6efc2bc4f19952b25ebf9b236e5ac43cd386c2 to < 7d659cb1763ff17d1c6ee082fa6feb4267c7a30baffected7b6efc2bc4f19952b25ebf9b236e5ac43cd386c2 to < a04cb99c5d4668fe3f5c0e5b6da1cecd34c3f219affected7b6efc2bc4f19952b25ebf9b236e5ac43cd386c2 to < 2358aa84ef6dafcf544a557caaa6b91afb4a0bd2affected7b6efc2bc4f19952b25ebf9b236e5ac43cd386c2 to < 04bc13dae4a27b8d030843c85ae452bb2f1d9c1faffected7b6efc2bc4f19952b25ebf9b236e5ac43cd386c2 to < 01e67e04c28170c47700c2c226d732bbfedb1ad0affected
Linux Linux
Default version status: affected
3.2affected0 to < 3.2unaffected4.9.311 to ≤ 4.9.*unaffected4.14.276 to ≤ 4.14.*unaffected4.19.238 to ≤ 4.19.*unaffected5.4.189 to ≤ 5.4.*unaffected5.10.111 to ≤ 5.10.*unaffected5.15.34 to ≤ 5.15.*unaffected5.16.20 to ≤ 5.16.*unaffected5.17.3 to ≤ 5.17.*unaffected5.18 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/a05540f3903bd8295e8c4cd90dd3d416239a115b ↗
- https://git.kernel.org/stable/c/eeaf28e2a0128147d687237e59d5407ee1b14693 ↗
- https://git.kernel.org/stable/c/e2c328c2a8f9de8b761bd4025b66c63120c55761 ↗
- https://git.kernel.org/stable/c/c19d8de4e682ec4b0ea2b04a832cd8cc0be3bb31 ↗
- https://git.kernel.org/stable/c/7d659cb1763ff17d1c6ee082fa6feb4267c7a30b ↗
- https://git.kernel.org/stable/c/a04cb99c5d4668fe3f5c0e5b6da1cecd34c3f219 ↗
- https://git.kernel.org/stable/c/2358aa84ef6dafcf544a557caaa6b91afb4a0bd2 ↗
- https://git.kernel.org/stable/c/04bc13dae4a27b8d030843c85ae452bb2f1d9c1f ↗
- https://git.kernel.org/stable/c/01e67e04c28170c47700c2c226d732bbfedb1ad0 ↗