In the Linux kernel, the following vulnerability has been resolved:
ftrace: Fix potential warning in trace_printk_seq during ftrace_dump
When calling ftrace_dump_one() concurrently with reading trace_pipe,
a WARN_ON_ONCE() in trace_printk_seq() can be triggered due to a race
condition.
The issue occurs because:
CPU0 (ftrace_dump) CPU1 (reader)
echo z > /proc/sysrq-trigger
!trace_empty(&iter)
trace_iterator_reset(&iter) <- len = size = 0
cat /sys/kernel/tracing/trace_pipe
trace_find_next_entry_inc(&iter)
__find_next_entry
ring_buffer_empty_cpu <- all empty
return NULL
trace_printk_seq(&iter.seq)
WARN_ON_ONCE(s->seq.len >= s->seq.size)
In the context between trace_empty() and trace_find_next_entry_inc()
during ftrace_dump, the ring buffer data was consumed by other readers.
This caused trace_find_next_entry_inc to return NULL, failing to populate
`iter.seq`. At this point, due to the prior trace_iterator_reset, both
`iter.seq.len` and `iter.seq.size` were set to 0. Since they are equal,
the WARN_ON_ONCE condition is triggered.
Move the trace_printk_seq() into the if block that checks to make sure the
return value of trace_find_next_entry_inc() is non-NULL in
ftrace_dump_one(), ensuring the 'iter.seq' is properly populated before
subsequent operations.
References
Configurations
Configuration 1 (hide)
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Configuration 2 (hide)
|
History
16 Jan 2026, 20:08
| Type | Values Removed | Values Added |
|---|---|---|
| CPE | cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.17:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.17:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
|
| References | () https://git.kernel.org/stable/c/28c8fb7ae2ad27d81c8de3c4fe608c509f6a18aa - Patch | |
| References | () https://git.kernel.org/stable/c/4013aef2ced9b756a410f50d12df9ebe6a883e4a - Patch | |
| References | () https://git.kernel.org/stable/c/5ab0ec206deb99eb3baf8f1d7602aeaa91dbcc85 - Patch | |
| References | () https://git.kernel.org/stable/c/a6f0f8873cc30fd4543b09adf03f7f51d293f0e6 - Patch | |
| References | () https://git.kernel.org/stable/c/ced94e137e6cd5e79c65564841d3b7695d0f5fa3 - Patch | |
| References | () https://git.kernel.org/stable/c/e80ff23ba8bdb0f41a1afe2657078e4097d13a9a - Patch | |
| References | () https://git.kernel.org/stable/c/f299353e7ccbcc5c2ed8993c48fbe7609cbe729a - Patch | |
| References | () https://git.kernel.org/stable/c/fbd4cf7ee4db65ef36796769fe978e9eba6f0de4 - Patch | |
| References | () https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html - Third Party Advisory | |
| References | () https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html - Third Party Advisory | |
| First Time |
Linux
Debian Debian debian Linux Linux linux Kernel |
|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 4.7 |
| CWE | CWE-362 |
03 Nov 2025, 18:16
| Type | Values Removed | Values Added |
|---|---|---|
| References |
|
16 Sep 2025, 13:15
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2025-09-16 13:15
Updated : 2026-01-16 20:08
NVD link : CVE-2025-39813
Mitre link : CVE-2025-39813
CVE.ORG link : CVE-2025-39813
JSON object : View
Products Affected
debian
- debian_linux
linux
- linux_kernel
CWE
CWE-362
Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')