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.

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact High

Integrity Impact High

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00016.

Exploitation none

Automatable no

Technical Impact total

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Linux Linux unaffected
Version Status Constraints
3083ee2e18b701122a3b841db83448543a87a583 affected
< ba5120a2fb5f23b4d39d302e181aa5d4e28a90d1
3083ee2e18b701122a3b841db83448543a87a583 affected
< 526ff5b27f090fb15040471f892cd2c9899ce314
3083ee2e18b701122a3b841db83448543a87a583 affected
< 66376f1a73cba57fd0af2631d7888605b738e499
3083ee2e18b701122a3b841db83448543a87a583 affected
< 9a466b8693b9add05de99af00c7bdff8259ecf19
3083ee2e18b701122a3b841db83448543a87a583 affected
< c3a403d8ce36f5a809a492581de5ad17843e4701
3083ee2e18b701122a3b841db83448543a87a583 affected
< 44f52bbe96dfdbe4aca3818a2534520082a07040
Linux Linux affected
Version Status Constraints
3.4 affected
—
0 unaffected
< 3.4
5.10.233 unaffected
≤ 5.10.*
5.15.176 unaffected
≤ 5.15.*
6.1.124 unaffected
≤ 6.1.*
6.6.70 unaffected
≤ 6.6.*
6.12.8 unaffected
≤ 6.12.*
6.13 unaffected
≤ *

Configuration 1 [-]

OR cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.13:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.13:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.13:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.13:rc4:*:*:*:*:*:*

No data.

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4075-1 linux security update
Debian DLA Debian DLA DLA-4076-1 linux-6.1 security update
EUVD EUVD EUVD-2024-53402 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.
Ubuntu USN Ubuntu USN USN-7379-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7379-2 Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN Ubuntu USN USN-7380-1 Linux kernel (Low Latency) vulnerabilities
Ubuntu USN Ubuntu USN USN-7381-1 Linux kernel (Low Latency) vulnerabilities
Ubuntu USN Ubuntu USN USN-7382-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-7387-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7387-2 Linux kernel (FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7387-3 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7388-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7389-1 Linux kernel (NVIDIA Tegra) vulnerabilities
Ubuntu USN Ubuntu USN USN-7390-1 Linux kernel (Xilinx ZynqMP) vulnerabilities
Ubuntu USN Ubuntu USN USN-7407-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-7421-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7458-1 Linux kernel (IBM) vulnerabilities
Ubuntu USN Ubuntu USN USN-7459-1 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-7459-2 Linux kernel (GCP) vulnerabilities
Ubuntu USN Ubuntu USN USN-7513-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7513-2 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7513-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7513-4 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-7513-5 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-7514-1 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-7515-1 Linux kernel (GKE) vulnerabilities
Ubuntu USN Ubuntu USN USN-7515-2 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7522-1 Linux kernel (Azure, N-Series) vulnerabilities
Ubuntu USN Ubuntu USN USN-7523-1 Linux kernel (Raspberry Pi Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7524-1 Linux kernel (Raspberry Pi) vulnerabilities
Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://git.kernel.org/stable/c/44f52bbe96dfdbe4aca3818a2534520082a07040 cve-icon cve-icon
https://git.kernel.org/stable/c/526ff5b27f090fb15040471f892cd2c9899ce314 cve-icon cve-icon
https://git.kernel.org/stable/c/66376f1a73cba57fd0af2631d7888605b738e499 cve-icon cve-icon
https://git.kernel.org/stable/c/9a466b8693b9add05de99af00c7bdff8259ecf19 cve-icon cve-icon
https://git.kernel.org/stable/c/ba5120a2fb5f23b4d39d302e181aa5d4e28a90d1 cve-icon cve-icon
https://git.kernel.org/stable/c/c3a403d8ce36f5a809a492581de5ad17843e4701 cve-icon cve-icon
https://lists.debian.org/debian-lts-announce/2025/03/msg00001.html cve-icon
https://lists.debian.org/debian-lts-announce/2025/03/msg00002.html cve-icon
https://lore.kernel.org/linux-cve-announce/2025010653-CVE-2024-56759-e46e@gregkh/T cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2024-56759 cve-icon
https://www.cve.org/CVERecord?id=CVE-2024-56759 cve-icon
History

Mon, 03 Nov 2025 21:30:00 +0000

Type Values Removed Values Added
References

Tue, 11 Feb 2025 16:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Thu, 09 Jan 2025 15:45:00 +0000

Type Values Removed Values Added
References

Tue, 07 Jan 2025 23:30:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses CWE-416
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.13:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.13:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.13:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:6.13:rc4:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

 cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}

Tue, 07 Jan 2025 01:30:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

 cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Moderate

Mon, 06 Jan 2025 16:30:00 +0000

Type Values Removed Values Added
Description 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.
Title btrfs: fix use-after-free when COWing tree bock and tracing is enabled
References
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-01-05T10:56:17.233Z

Reserved: 2024-12-29T11:26:39.761Z

Link: CVE-2024-56759

cve-icon Vulnrichment

Updated: 2025-11-03T20:53:52.637Z

cve-icon NVD

Status : Modified

Published: 2025-01-06T17:15:40.900

Modified: 2025-11-03T21:18:27.983

Link: CVE-2024-56759

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-01-06T00:00:00Z

Links: CVE-2024-56759 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses