CVE-2025-21747: drm/ast: astdp: Fix timeout for enabling video signal

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-02-27 · updated 2026-06-17

Description

In the Linux kernel, the following vulnerability has been resolved: drm/ast: astdp: Fix timeout for enabling video signal 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.

Affected products

Linux kernel: from 6.13 before 6.13.3; 6.14-rc1 — fixed in 6.13.3

How to fix

Upgrade to a fixed version: Linux kernel 6.13.3. Check the vendor advisory for mitigations.

References

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