CVE-2022-49077
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…
Does this matter?
Lower severity and a low EPSS score (0.25%). Track it; it rarely justifies an emergency change on its own.
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.
- CVSS 3.1
- 5.5 MEDIUMCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.25% probability · 16th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-193
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/01e67e04c28170c47700c2c226d732bbfedb1ad0Patch
- https://git.kernel.org/stable/c/04bc13dae4a27b8d030843c85ae452bb2f1d9c1fPatch
- https://git.kernel.org/stable/c/2358aa84ef6dafcf544a557caaa6b91afb4a0bd2Patch
- https://git.kernel.org/stable/c/7d659cb1763ff17d1c6ee082fa6feb4267c7a30bPatch
- https://git.kernel.org/stable/c/a04cb99c5d4668fe3f5c0e5b6da1cecd34c3f219Patch
- https://git.kernel.org/stable/c/a05540f3903bd8295e8c4cd90dd3d416239a115bPatch
- https://git.kernel.org/stable/c/c19d8de4e682ec4b0ea2b04a832cd8cc0be3bb31Patch
- https://git.kernel.org/stable/c/e2c328c2a8f9de8b761bd4025b66c63120c55761Patch
- https://git.kernel.org/stable/c/eeaf28e2a0128147d687237e59d5407ee1b14693Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.