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

tracing: Fix use-after-free in print_graph_function_flags during tracer switching

Kairui reported a UAF issue in print_graph_function_flags() during
ftrace stress testing [1]. This issue can be reproduced if puting a
'mdelay(10)' after 'mutex_unlock(&trace_types_lock)' in s_start(),
and executing the following script:

$ echo function_graph > current_tracer
$ cat trace > /dev/null &
$ sleep 5 # Ensure the 'cat' reaches the 'mdelay(10)' point
$ echo timerlat > current_tracer

The root cause lies in the two calls to print_graph_function_flags
within print_trace_line during each s_show():

* One through 'iter->trace->print_line()';
* Another through 'event->funcs->trace()', which is hidden in
print_trace_fmt() before print_trace_line returns.

Tracer switching only updates the former, while the latter continues
to use the print_line function of the old tracer, which in the script
above is print_graph_function_flags.

Moreover, when switching from the 'function_graph' tracer to the
'timerlat' tracer, s_start only calls graph_trace_close of the
'function_graph' tracer to free 'iter->private', but does not set
it to NULL. This provides an opportunity for 'event->funcs->trace()'
to use an invalid 'iter->private'.

To fix this issue, set 'iter->private' to NULL immediately after
freeing it in graph_trace_close(), ensuring that an invalid pointer
is not passed to other tracers. Additionally, clean up the unnecessary
'iter->private = NULL' during each 'cat trace' when using wakeup and
irqsoff tracers.

[1] https://lore.kernel.org/all/20231112150030.84609-1-ryncsn@gmail.com/
Published: 2025-04-16
Score: 7.8 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
Debian DLA Debian DLA DLA-4178-1 linux security update
Debian DLA Debian DLA DLA-4193-1 linux-6.1 security update
Debian DSA Debian DSA DSA-5907-1 linux security update
EUVD EUVD EUVD-2025-11251 In the Linux kernel, the following vulnerability has been resolved: tracing: Fix use-after-free in print_graph_function_flags during tracer switching Kairui reported a UAF issue in print_graph_function_flags() during ftrace stress testing [1]. This issue can be reproduced if puting a 'mdelay(10)' after 'mutex_unlock(&trace_types_lock)' in s_start(), and executing the following script: $ echo function_graph > current_tracer $ cat trace > /dev/null & $ sleep 5 # Ensure the 'cat' reaches the 'mdelay(10)' point $ echo timerlat > current_tracer The root cause lies in the two calls to print_graph_function_flags within print_trace_line during each s_show(): * One through 'iter->trace->print_line()'; * Another through 'event->funcs->trace()', which is hidden in print_trace_fmt() before print_trace_line returns. Tracer switching only updates the former, while the latter continues to use the print_line function of the old tracer, which in the script above is print_graph_function_flags. Moreover, when switching from the 'function_graph' tracer to the 'timerlat' tracer, s_start only calls graph_trace_close of the 'function_graph' tracer to free 'iter->private', but does not set it to NULL. This provides an opportunity for 'event->funcs->trace()' to use an invalid 'iter->private'. To fix this issue, set 'iter->private' to NULL immediately after freeing it in graph_trace_close(), ensuring that an invalid pointer is not passed to other tracers. Additionally, clean up the unnecessary 'iter->private = NULL' during each 'cat trace' when using wakeup and irqsoff tracers. [1] https://lore.kernel.org/all/20231112150030.84609-1-ryncsn@gmail.com/
Ubuntu USN Ubuntu USN USN-7585-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7585-2 Linux kernel (FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7585-3 Linux kernel (FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7585-4 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7585-5 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-7585-6 Linux kernel (BlueField) vulnerabilities
Ubuntu USN Ubuntu USN USN-7585-7 Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN Ubuntu USN USN-7591-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7591-2 Linux kernel (FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7591-3 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7591-4 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7591-5 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-7591-6 Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN Ubuntu USN USN-7592-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7593-1 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-7594-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7594-2 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7594-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7597-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7597-2 Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7598-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7602-1 Linux kernel (Xilinx ZynqMP) vulnerabilities
Ubuntu USN Ubuntu USN USN-7605-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7605-2 Linux kernel (Low Latency) vulnerabilities
Ubuntu USN Ubuntu USN USN-7606-1 Linux kernel (OEM) vulnerabilities
Ubuntu USN Ubuntu USN USN-7628-1 Linux kernel (Azure) vulnerabilities
Ubuntu USN Ubuntu USN USN-7640-1 Linux kernel (IoT) vulnerabilities
Ubuntu USN Ubuntu USN USN-7655-1 Linux kernel (Intel IoTG) vulnerabilities
Ubuntu USN Ubuntu USN USN-7835-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7835-2 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7835-3 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7835-4 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-7835-5 Linux kernel (Oracle) vulnerabilities
Ubuntu USN Ubuntu USN USN-7835-6 Linux kernel (AWS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7887-1 Linux kernel (Raspberry Pi Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7887-2 Linux kernel (Raspberry Pi) vulnerabilities
Ubuntu USN Ubuntu USN USN-7940-1 Linux kernel (Azure FIPS) vulnerabilities
Ubuntu USN Ubuntu USN USN-7940-2 Linux kernel (Azure, N-Series) vulnerabilities
History

Mon, 03 Nov 2025 20:30:00 +0000

Type Values Removed Values Added
References

Fri, 25 Apr 2025 19:00:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel

Mon, 21 Apr 2025 15:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-416
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'}

 ssvc

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

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'}

Fri, 18 Apr 2025 02:45:00 +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

Wed, 16 Apr 2025 14:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: tracing: Fix use-after-free in print_graph_function_flags during tracer switching Kairui reported a UAF issue in print_graph_function_flags() during ftrace stress testing [1]. This issue can be reproduced if puting a 'mdelay(10)' after 'mutex_unlock(&trace_types_lock)' in s_start(), and executing the following script: $ echo function_graph > current_tracer $ cat trace > /dev/null & $ sleep 5 # Ensure the 'cat' reaches the 'mdelay(10)' point $ echo timerlat > current_tracer The root cause lies in the two calls to print_graph_function_flags within print_trace_line during each s_show(): * One through 'iter->trace->print_line()'; * Another through 'event->funcs->trace()', which is hidden in print_trace_fmt() before print_trace_line returns. Tracer switching only updates the former, while the latter continues to use the print_line function of the old tracer, which in the script above is print_graph_function_flags. Moreover, when switching from the 'function_graph' tracer to the 'timerlat' tracer, s_start only calls graph_trace_close of the 'function_graph' tracer to free 'iter->private', but does not set it to NULL. This provides an opportunity for 'event->funcs->trace()' to use an invalid 'iter->private'. To fix this issue, set 'iter->private' to NULL immediately after freeing it in graph_trace_close(), ensuring that an invalid pointer is not passed to other tracers. Additionally, clean up the unnecessary 'iter->private = NULL' during each 'cat trace' when using wakeup and irqsoff tracers. [1] https://lore.kernel.org/all/20231112150030.84609-1-ryncsn@gmail.com/
Title tracing: Fix use-after-free in print_graph_function_flags during tracer switching
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-05-11T21:11:22.784Z

Reserved: 2024-12-29T08:45:45.809Z

Link: CVE-2025-22035

cve-icon Vulnrichment

Updated: 2025-11-03T19:41:18.919Z

cve-icon NVD

Status : Modified

Published: 2025-04-16T15:15:56.110

Modified: 2025-11-03T20:17:38.707

Link: CVE-2025-22035

cve-icon Redhat

Severity : Moderate

Publid Date: 2025-04-16T00:00:00Z

Links: CVE-2025-22035 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses