CVE-2024-56759
- Source
- https://cve.org/CVERecord?id=CVE-2024-56759
- Import Source
- https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2024-56759.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/CVE-2024-56759
- Downstream
- Related
- Published
- 2025-01-06T16:20:39Z
- Modified
- 2026-08-12T03:30:52Z
- Severity
-
- 7.8 (High) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
- Summary
- btrfs: fix use-after-free when COWing tree bock and tracing is enabled
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
btrfs: fix use-after-free when COWing tree bock and tracing is enabled
When a COWing a tree block, at btrfs_cow_block(), and we have the tracepoint trace_btrfs_cow_block() enabled and preemption is also enabled (CONFIG_PREEMPT=y), we can trigger a use-after-free in the COWed extent buffer while inside the tracepoint code. This is because in some paths that call btrfs_cow_block(), such as btrfs_search_slot(), we are holding the last reference on the extent buffer @buf so btrfs_force_cow_block() drops the last reference on the @buf extent buffer when it calls free_extent_buffer_stale(buf), which schedules the release of the extent buffer with RCU. This means that if we are on a kernel with preemption, the current task may be preempted before calling trace_btrfs_cow_block() and the extent buffer already released by the time trace_btrfs_cow_block() is called, resulting in a use-after-free.
Fix this by moving the trace_btrfs_cow_block() from btrfs_cow_block() to btrfs_force_cow_block() before the COWed extent buffer is freed. This also has a side effect of invoking the tracepoint in the tree defrag code, at defrag.c:btrfs_realloc_node(), since btrfs_force_cow_block() is called there, but this is fine and it was actually missing there.
- Database specific
{ "cna_assigner": "Linux", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/56xxx/CVE-2024-56759.json" }- References
-
- https://git.kernel.org/stable/c/44f52bbe96dfdbe4aca3818a2534520082a07040
- https://git.kernel.org/stable/c/526ff5b27f090fb15040471f892cd2c9899ce314
- https://git.kernel.org/stable/c/66376f1a73cba57fd0af2631d7888605b738e499
- https://git.kernel.org/stable/c/9a466b8693b9add05de99af00c7bdff8259ecf19
- https://git.kernel.org/stable/c/ba5120a2fb5f23b4d39d302e181aa5d4e28a90d1
- https://git.kernel.org/stable/c/c3a403d8ce36f5a809a492581de5ad17843e4701
- https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html
- https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/56xxx/CVE-2024-56759.json
- https://nvd.nist.gov/vuln/detail/CVE-2024-56759
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected packages
Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected ranges
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced3083ee2e18b701122a3b841db83448543a87a583Fixedba5120a2fb5f23b4d39d302e181aa5d4e28a90d1Fixed526ff5b27f090fb15040471f892cd2c9899ce314Fixed66376f1a73cba57fd0af2631d7888605b738e499Fixed9a466b8693b9add05de99af00c7bdff8259ecf19Fixedc3a403d8ce36f5a809a492581de5ad17843e4701Fixed44f52bbe96dfdbe4aca3818a2534520082a07040
Linux / Kernel
Package
- Name
- Kernel