7.8

CVE-2024-49854

block, bfq: fix uaf for accessing waker_bfqq after splitting

In the Linux kernel, the following vulnerability has been resolved:

block, bfq: fix uaf for accessing waker_bfqq after splitting

After commit 42c306ed7233 ("block, bfq: don't break merge chain in
bfq_split_bfqq()"), if the current procress is the last holder of bfqq,
the bfqq can be freed after bfq_split_bfqq(). Hence recored the bfqq and
then access bfqq->waker_bfqq may trigger UAF. What's more, the waker_bfqq
may in the merge chain of bfqq, hence just recored waker_bfqq is still
not safe.

Fix the problem by adding a helper bfq_waker_bfqq() to check if
bfqq->waker_bfqq is in the merge chain, and current procress is the only
holder.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Linux ≫ Linux Kernel Version >= 5.10.227 < 5.15.168
Linux ≫ Linux Kernel Version >= 5.16 < 6.1.113
Linux ≫ Linux Kernel Version >= 6.2 < 6.6.54
Linux ≫ Linux Kernel Version >= 6.7 < 6.10.13
Linux ≫ Linux Kernel Version >= 6.11 < 6.11.2
VulnDex Vulnerability Enrichment
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.22% 0.119
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 7.8 1.8 5.9
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE-416 Use After Free

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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

https://git.kernel.org/stable/c/0780451f03bf518bc032a7c584de8f92e2d39d7f
Patch
https://git.kernel.org/stable/c/0b8bda0ff17156cd3f60944527c9d8c9f99f1583
Patch
https://git.kernel.org/stable/c/1ba0403ac6447f2d63914fb760c44a3b19c44eaf
Patch
https://git.kernel.org/stable/c/63a07379fdb6c72450cb05294461c6016b8b7726
Patch
https://git.kernel.org/stable/c/cae58d19121a70329cf971359e2518c93fec04fe
Patch
https://git.kernel.org/stable/c/de0456460f2abf921e356ed2bd8da87a376680bd
Patch
https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html