CVE-2023-53709
Description
In the Linux kernel, the following vulnerability has been resolved:
ring-buffer: Handle race between rb_move_tail and rb_check_pages
It seems a data race between ring_buffer writing and integrity check. That is, RB_FLAG of head_page is been updating, while at same time RB_FLAG was cleared when doing integrity check rb_check_pages():
rb_check_pages() rb_handle_head_page(): -------- -------- rb_head_page_deactivate() rb_head_page_set_normal() rb_head_page_activate()
We do intergrity test of the list to check if the list is corrupted and it is still worth doing it. So, let's refactor rb_check_pages() such that we no longer clear and set flag during the list sanity checking.
[1] and [2] are the test to reproduce and the crash report respectively.
1: `` read_trace.sh while true; do # the "trace" file is closed after read head -1 /sys/kernel/tracing/trace > /dev/null done ``
sysctl -w kernel.panic_on_warn=1
# function tracer will writing enough data into ring_buffer
echo function > /sys/kernel/tracing/current_tracer
./read_trace.sh &
./read_trace.sh &
./read_trace.sh &
./read_trace.sh &
./read_trace.sh &
./read_trace.sh &
./read_trace.sh &
./read_trace.sh &
2: ------------[ cut here ]------------ WARNING: CPU: 9 PID: 62 at kernel/trace/ring_buffer.c:2653 rb_move_tail+0x450/0x470 Modules linked in: CPU: 9 PID: 62 Comm: ksoftirqd/9 Tainted: G W 6.2.0-rc6+ Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.15.0-0-g2dd4b9b3f840-prebuilt.qemu.org 04/01/2014 RIP: 0010:rb_move_tail+0x450/0x470 Code: ff ff 4c 89 c8 f0 4d 0f b1 02 48 89 c2 48 83 e2 fc 49 39 d0 75 24 83 e0 03 83 f8 02 0f 84 e1 fb ff ff 48 8b 57 10 f0 ff 42 08 <0f> 0b 83 f8 02 0f 84 ce fb ff ff e9 db RSP: 0018:ffffb5564089bd00 EFLAGS: 00000203 RAX: 0000000000000000 RBX: ffff9db385a2bf81 RCX: ffffb5564089bd18 RDX: ffff9db281110100 RSI: 0000000000000fe4 RDI: ffff9db380145400 RBP: ffff9db385a2bf80 R08: ffff9db385a2bfc0 R09: ffff9db385a2bfc2 R10: ffff9db385a6c000 R11: ffff9db385a2bf80 R12: 0000000000000000 R13: 00000000000003e8 R14: ffff9db281110100 R15: ffffffffbb006108 FS: 0000000000000000(0000) GS:ffff9db3bdcc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005602323024c8 CR3: 0000000022e0c000 CR4: 00000000000006e0 Call Trace:
ring_buffer_lock_reserve+0x136/0x360 ? __do_softirq+0x287/0x2df ? __pfx_rcu_softirq_qs+0x10/0x10 trace_function+0x21/0x110 ? __pfx_rcu_softirq_qs+0x10/0x10 ? __do_softirq+0x287/0x2df function_trace_call+0xf6/0x120 0xffffffffc038f097 ? rcu_softirq_qs+0x5/0x140 rcu_softirq_qs+0x5/0x140 __do_softirq+0x287/0x2df run_ksoftirqd+0x2a/0x30 smpboot_thread_fn+0x188/0x220 ? __pfx_smpboot_thread_fn+0x10/0x10 kthread+0xe7/0x110 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x2c/0x50
---[ end trace 0000000000000000 ]---
[ crash report and test reproducer credit goes to Zheng Yejian]
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
A race condition in the Linux kernel's ring buffer between rb_move_tail and rb_check_pages can cause a kernel panic (WARN_ON) when the ring buffer integrity check concurrently modifies flags while the buffer is being written.
Vulnerability
Details
CVE-2023-53709 is a data race in the Linux kernel's ring buffer implementation, specifically between the rb_move_tail function (used during buffer writes) and the rb_check_pages integrity check function. The race occurs because rb_check_pages clears and then sets a flag (RB_FLAG) on the head page while another thread concurrently updates that same flag during a normal ring buffer write operation [1].
Exploitation
Scenarios
The vulnerability can be triggered by concurrently reading and writing the kernel trace ring buffer. As shown in the provided reproducer [1], the attack surface involves multiple userspace processes reading the trace file (e.g., /sys/kernel/tracing/trace) while the function tracer is enabled, causing high-frequency buffer writes. No special privileges beyond read access to the trace file are required—a local unprivileged user can exploit this race condition to crash the system.
Impact
A successful exploit results in a kernel warning (WARN_ON) and a subsequent kernel panic if the kernel.panic_on_warn sysctl is enabled. This constitutes a denial-of-service (DoS) condition, crashing the entire system. The crash report shows a kernel panic in rb_move_tail [2], indicating that the race can corrupt the ring buffer's internal state.
Mitigation
Status
The fix, which refactors rb_check_pages to avoid clearing and setting flags during the integrity check, has been merged into the Linux kernel stable tree [1]. Linux distributions that have backported the commit (8843e06f67b14f71c044bf6267b2387784c7e198) are patched. Users should update their kernels to the latest stable release to mitigate this vulnerability.
AI Insight generated on May 19, 2026. Synthesized from this CVE's description and the cited reference URLs; citations are validated against the source bundle.
Affected products
1Patches
56e02a43acd06d41db100bc389674390ac54009b1bf25f7f78843e06f67b1Vulnerability mechanics
Generated on May 9, 2026. Inputs: CWE entries + fix-commit diffs from this CVE's patches. Citations validated against bundle.
References
5- git.kernel.org/stable/c/09b1bf25f7f7a8f2bf8cd4278bba9c3172db8013nvd
- git.kernel.org/stable/c/6e02a43acd0691791df79ce538f2dd497a6c9b76nvd
- git.kernel.org/stable/c/8843e06f67b14f71c044bf6267b2387784c7e198nvd
- git.kernel.org/stable/c/9674390ac540ed06768e3fbc2dba553929fbd736nvd
- git.kernel.org/stable/c/d41db100bc386b9433a3fc87026f5e8b453653e3nvd
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