Vulnerability Details : CVE-2022-48649
In the Linux kernel, the following vulnerability has been resolved:
mm/slab_common: fix possible double free of kmem_cache
When doing slub_debug test, kfence's 'test_memcache_typesafe_by_rcu'
kunit test case cause a use-after-free error:
BUG: KASAN: use-after-free in kobject_del+0x14/0x30
Read of size 8 at addr ffff888007679090 by task kunit_try_catch/261
CPU: 1 PID: 261 Comm: kunit_try_catch Tainted: G B N 6.0.0-rc5-next-20220916 #17
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Call Trace:
<TASK>
dump_stack_lvl+0x34/0x48
print_address_description.constprop.0+0x87/0x2a5
print_report+0x103/0x1ed
kasan_report+0xb7/0x140
kobject_del+0x14/0x30
kmem_cache_destroy+0x130/0x170
test_exit+0x1a/0x30
kunit_try_run_case+0xad/0xc0
kunit_generic_run_threadfn_adapter+0x26/0x50
kthread+0x17b/0x1b0
</TASK>
The cause is inside kmem_cache_destroy():
kmem_cache_destroy
acquire lock/mutex
shutdown_cache
schedule_work(kmem_cache_release) (if RCU flag set)
release lock/mutex
kmem_cache_release (if RCU flag not set)
In some certain timing, the scheduled work could be run before
the next RCU flag checking, which can then get a wrong value
and lead to double kmem_cache_release().
Fix it by caching the RCU flag inside protected area, just like 'refcnt'
Vulnerability category: Memory Corruption
Products affected by CVE-2022-48649
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Exploit prediction scoring system (EPSS) score for CVE-2022-48649
0.07%
Probability of exploitation activity in the next 30 days
EPSS Score History
~ 17 %
Percentile, the proportion of vulnerabilities that are scored at or less
CVSS scores for CVE-2022-48649
| Base Score | Base Severity | CVSS Vector | Exploitability Score | Impact Score | Score Source | First Seen |
|---|---|---|---|---|---|---|
|
7.8
|
HIGH | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
1.8
|
5.9
|
NIST | 2025-01-10 |
CWE ids for CVE-2022-48649
-
The product calls free() twice on the same memory address.Assigned by: nvd@nist.gov (Primary)
-
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.Assigned by: nvd@nist.gov (Primary)
References for CVE-2022-48649
-
https://git.kernel.org/stable/c/d71608a877362becdc94191f190902fac1e64d35
mm/slab_common: fix possible double free of kmem_cache - kernel/git/stable/linux.git - Linux kernel stable treePatch
-
https://git.kernel.org/stable/c/c673c6ceac53fb2e631c9fbbd79957099a08927f
mm/slab_common: fix possible double free of kmem_cache - kernel/git/stable/linux.git - Linux kernel stable treePatch
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