CVE-2024-35846
mm: zswap: fix shrinker NULL crash with cgroup_disable=memory
Severity Score
Exploit Likelihood
Affected Versions
Public Exploits
0Exploited in Wild
-Decision
Descriptions
In the Linux kernel, the following vulnerability has been resolved:
mm: zswap: fix shrinker NULL crash with cgroup_disable=memory
Christian reports a NULL deref in zswap that he bisected down to the zswap
shrinker. The issue also cropped up in the bug trackers of libguestfs [1]
and the Red Hat bugzilla [2].
The problem is that when memcg is disabled with the boot time flag, the
zswap shrinker might get called with sc->memcg == NULL. This is okay in
many places, like the lruvec operations. But it crashes in
memcg_page_state() - which is only used due to the non-node accounting of
cgroup's the zswap memory to begin with.
Nhat spotted that the memcg can be NULL in the memcg-disabled case, and I
was then able to reproduce the crash locally as well.
[1] https://github.com/libguestfs/libguestfs/issues/139
[2] https://bugzilla.redhat.com/show_bug.cgi?id=2275252
En el kernel de Linux, se resolvió la siguiente vulnerabilidad: mm: zswap: corrige el bloqueo NULL del reductor con cgroup_disable=memory. Christian informa una deref NULL en zswap que dividió en dos hasta el reductor zswap. El problema también surgió en los rastreadores de errores de libguestfs [1] y Red Hat bugzilla [2]. El problema es que cuando memcg está deshabilitado con el indicador de tiempo de arranque, es posible que se llame al reductor zswap con sc->memcg == NULL. Esto está bien en muchos lugares, como en las operaciones de lruvec. Pero fallo en memcg_page_state(), que para empezar solo se usa debido a la contabilidad sin nodos de la memoria zswap de cgroup. Nhat detectó que memcg puede ser NULL en el caso de que memcg esté deshabilitado y luego también pude reproducir el fallo localmente. [1] https://github.com/libguestfs/libguestfs/issues/139 [2] https://bugzilla.redhat.com/show_bug.cgi?id=2275252
CVSS Scores
SSVC
- Decision:Track
Timeline
- 2024-05-17 CVE Reserved
- 2024-05-17 CVE Published
- 2024-05-18 EPSS Updated
- 2024-08-02 CVE Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
- ---------- First Exploit
CWE
CAPEC
References (3)
| URL | Tag | Source |
|---|---|---|
| https://git.kernel.org/stable/c/b5ba474f3f518701249598b35c581b92a3c95b48 | Vuln. Introduced |
| URL | Date | SRC |
|---|
| URL | Date | SRC |
|---|---|---|
| https://git.kernel.org/stable/c/b0fdabc908a7f81d12382c87ca9e46a9c2e14042 | 2024-05-02 | |
| https://git.kernel.org/stable/c/682886ec69d22363819a83ddddd5d66cb5c791e1 | 2024-04-25 |
| URL | Date | SRC |
|---|
Affected Vendors, Products, and Versions
| Vendor | Product | Version | Other | Status | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Vendor | Product | Version | Other | Status | <-- --> | Vendor | Product | Version | Other | Status |
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 6.8 < 6.8.9 Search vendor "Linux" for product "Linux Kernel" and version " >= 6.8 < 6.8.9" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 6.8 < 6.9 Search vendor "Linux" for product "Linux Kernel" and version " >= 6.8 < 6.9" | en |
Affected
| ||||||