drm/ast: astdp: Fix timeout for enabling video signal

published 2025-02-27 20 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-5191

cvss: 5.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 6%
public exploits: 0; none known

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

The ASTDP transmitter sometimes takes up to 1 second for enabling the video signal, while the timeout is only 200 msec. This results in a kernel error message. Increase the timeout to 1 second. An example of the error message is shown below.

[ 697.084433] ------------[ cut here ]------------ [ 697.091115] ast 0000:02:00.0: [drm] drm_WARN_ON(!__ast_dp_wait_enable(ast, enabled)) [ 697.091233] WARNING: CPU: 1 PID: 160 at drivers/gpu/drm/ast/ast_dp.c:232 ast_dp_set_enable+0x123/0x140 [ast] [...] [ 697.272469] RIP: 0010:ast_dp_set_enable+0x123/0x140 [ast] [...] [ 697.415283] Call Trace: [ 697.420727] <TASK> [ 697.425908] ? show_trace_log_lvl+0x196/0x2c0 [ 697.433304] ? show_trace_log_lvl+0x196/0x2c0 [ 697.440693] ? drm_atomic_helper_commit_modeset_enables+0x30a/0x470 [ 697.450115] ? ast_dp_set_enable+0x123/0x140 [ast] [ 697.458059] ? __warn.cold+0xaf/0xca [ 697.464713] ? ast_dp_set_enable+0x123/0x140 [ast] [ 697.472633] ? report_bug+0x134/0x1d0 [ 697.479544] ? handle_bug+0x58/0x90 [ 697.486127] ? exc_invalid_op+0x13/0x40 [ 697.492975] ? asm_exc_invalid_op+0x16/0x20 [ 697.500224] ? preempt_count_sub+0x14/0xc0 [ 697.507473] ? ast_dp_set_enable+0x123/0x140 [ast] [ 697.515377] ? ast_dp_set_enable+0x123/0x140 [ast] [ 697.523227] drm_atomic_helper_commit_modeset_enables+0x30a/0x470 [ 697.532388] drm_atomic_helper_commit_tail+0x58/0x90 [ 697.540400] ast_mode_config_helper_atomic_commit_tail+0x30/0x40 [ast] [ 697.550009] commit_tail+0xfe/0x1d0 [ 697.556547] drm_atomic_helper_commit+0x198/0x1c0

This is a cosmetical problem. Enabling the video signal still works even with the error message. The problem has always been present, but only recent versions of the ast driver warn about missing the timeout.

Patch / fix

fixed in 1 links 2

Linux Linux 6.13.3, 6.14

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2025-21747 updated 2026-11-06

kernel: drm/ast: astdp: Fix timeout for enabling video signal

Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more Red Hat Enterprise Linux 10 kernel
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

Linux Linux

Classification

Technology feeds

Linux kernel rss critical rss

References

Sources

CVE List CVE-2025-21747
NVD CVE-2025-21747

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary