CVE-2024-26689
Medium
Elevated severity or exploit probability.
CVSS breakdown
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
| Attack Vector | N | Network |
| Attack Complexity | L | Low |
| Privileges Required | L | Low |
| User Interaction | N | None |
| Scope | U | Unchanged |
| Confidentiality | H | High |
| Integrity | H | High |
| Availability | H | High |
Timeline
- 2024-04-03 — Published (NVD)
- 2026-08-04 — Last modified (NVD)
Description
In the Linux kernel, the following vulnerability has been resolved: ceph: prevent use-after-free in encode_cap_msg() In fs/ceph/caps.c, in encode_cap_msg(), "use after free" error was caught by KASAN at this line - 'ceph_buffer_get(arg->xattr_buf);'. This implies before the refcount could be increment here, it was freed. In same file, in "handle_cap_grant()" refcount is decremented by this line - 'ceph_buffer_put(ci->i_xattrs.blob);'. It appears that a race occurred and resource was freed by the latter line before the former line could increment it. encode_cap_msg() is called by __send_cap() and __send_cap() is called by ceph_check_caps() after calling __prep_cap(). __prep_cap() is where arg->xattr_buf is assigned to ci->i_xattrs.blob. This is the spot where the refcount must be increased to prevent "use after free" error.
Affected
References
- https://git.kernel.org/stable/c/70e329b440762390258a6fe8c0de93c9fdd56c77
- https://git.kernel.org/stable/c/7958c1bf5b03c6f1f58e724dbdec93f8f60b96fc
- https://git.kernel.org/stable/c/8180d0c27b93a6eb60da1b08ea079e3926328214
- https://git.kernel.org/stable/c/ae20db45e482303a20e56f2db667a9d9c54ac7e7
- https://git.kernel.org/stable/c/cda4672da1c26835dcbd7aec2bfed954eda9b5ef
- https://git.kernel.org/stable/c/f3f98d7d84b31828004545e29fd7262b9f444139
- https://git.kernel.org/stable/c/70e329b440762390258a6fe8c0de93c9fdd56c77
- https://git.kernel.org/stable/c/7958c1bf5b03c6f1f58e724dbdec93f8f60b96fc
- https://git.kernel.org/stable/c/8180d0c27b93a6eb60da1b08ea079e3926328214
- https://git.kernel.org/stable/c/ae20db45e482303a20e56f2db667a9d9c54ac7e7
- https://git.kernel.org/stable/c/cda4672da1c26835dcbd7aec2bfed954eda9b5ef
- https://git.kernel.org/stable/c/f3f98d7d84b31828004545e29fd7262b9f444139
- https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html