CVE-2022-50569
In the Linux kernel, the following vulnerability has been resolved: xfrm: Update ipcomp_scratches with NULL when freed Currently if ipcomp_alloc_scratches() fails to allocate memory ipcomp_scratches holds obsolete address.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.16%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
In the Linux kernel, the following vulnerability has been resolved: xfrm: Update ipcomp_scratches with NULL when freed Currently if ipcomp_alloc_scratches() fails to allocate memory ipcomp_scratches holds obsolete address. So when we try to free the percpu scratches using ipcomp_free_scratches() it tries to vfree non existent vm area. Described below: static void * __percpu *ipcomp_alloc_scratches(void) { ... scratches = alloc_percpu(void *); if (!scratches) return NULL; ipcomp_scratches does not know about this allocation failure. Therefore holding the old obsolete address. ... } So when we free, static void ipcomp_free_scratches(void) { ... scratches = ipcomp_scratches; Assigning obsolete address from ipcomp_scratches if (!scratches) return; for_each_possible_cpu(i) vfree(*per_cpu_ptr(scratches, i)); Trying to free non existent page, causing warning: trying to vfree existent vm area. ... } Fix this breakage by updating ipcomp_scrtches with NULL when scratches is freed
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.16% probability · 6th percentile
- CISA KEV
- Not listed
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
References
- https://git.kernel.org/stable/c/03155680191ef0f004b1d6a5714c5b8cd271ab61
- https://git.kernel.org/stable/c/18373ed500f7cd53e24d9b0bd0f1c09d78dba87e
- https://git.kernel.org/stable/c/1e8abde895b3ac6a368cbdb372e8800c49e73a28
- https://git.kernel.org/stable/c/2c19945ce8095d065df550e7fe350cd5cc40c6e6
- https://git.kernel.org/stable/c/8a04d2fc700f717104bfb95b0f6694e448a4537f
- https://git.kernel.org/stable/c/a39f456d62810c0efb43cead22f98d95b53e4b1a
- https://git.kernel.org/stable/c/be81c44242b20fc3bdcc73480ef8aaee56f5d0b6
- https://git.kernel.org/stable/c/debca61df6bc2f65e020656c9c5b878d6b38d30f
- https://git.kernel.org/stable/c/f3bdba4440d82e0da2b1bfc35d3836c8a8e00677
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.