# CVE-2025-37923: tracing: Fix oob write in trace\_seq\_to\_buffer()

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Known exploited (CISA KEV): no
- Published: 2025-05-20 · Updated: 2026-08-05

## Affected

- Linux: version range not reported
- Linux: 2.6.30

## Description

In the Linux kernel, the following vulnerability has been resolved: tracing: Fix oob write in trace_seq_to_buffer() syzbot reported this bug: ================================================================== BUG: KASAN: slab-out-of-bounds in trace_seq_to_buffer kernel/trace/trace.c:1830 [inline] BUG: KASAN: slab-out-of-bounds in tracing_splice_read_pipe+0x6be/0xdd0 kernel/trace/trace.c:6822 Write of size 4507 at addr ffff888032b6b000 by task syz.2.320/7260 CPU: 1 UID: 0 PID: 7260 Comm: syz.2.320 Not tainted 6.15.0-rc1-syzkaller-00301-g3bde70a2c827 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Call Trace: <TASK> __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:408 [inline] print_report+0xc3/0x670 mm/kasan/report.c:521 kasan_report+0xe0/0x110 mm/kasan/report.c:634 check_region_inline mm/kasan/generic.c:183 [inline] kasan_check_range+0xef/0x1a0 mm/kasan/generic.c:189 __asan_memcpy+0x3c/0x60 mm/kasan/shadow.c:106 trace_seq_to_buffer kernel/trace/trace.c:1830 [inline] tracing_splice_read_pipe+0x6be/0xdd0 kernel/trace/trace.c:6822 .... ================================================================== It has been reported that trace_seq_to_buffer() tries to copy more data than PAGE_SIZE to buf. Therefore, to prevent this, we should use the smaller of trace_seq_used(&iter->seq) and PAGE_SIZE as an argument.

## What to do

- Check your stack: if you ship or depend on Linux kernel, no fixed version is listed yet; follow the vendor advisory per the references below.
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## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/f4b0174e9f18aaba59ee6ffdaf8827a7f94eb606
- https://git.kernel.org/stable/c/665ce421041890571852422487f4c613d1824ba9
- https://git.kernel.org/stable/c/1a3f9482b50b74fa9421bff8ceecfefd0dc06f8f
- https://git.kernel.org/stable/c/441021e5b3c7d9bd1b963590652c415929f3b157
- https://git.kernel.org/stable/c/056ebbddb8faf4ddf83d005454dd78fc25c2d897
- https://git.kernel.org/stable/c/1f27a3e93b8d674b24b27fcdbc6f72743cd96c0d
- https://git.kernel.org/stable/c/c5d2b66c5ef5037b4b4360e5447605ff00ba1bd4
- https://git.kernel.org/stable/c/f5178c41bb43444a6008150fe6094497135d07cb

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