CVE-2025-21747

Summary

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 Software

VendorProductVersion RangeStatus
LinuxLinux4e29cc7c5c673299cfbaf4982fc8b6a72c9f706f < 589839379031cce220c9cab9f27cb5477195067eaffected
LinuxLinux4e29cc7c5c673299cfbaf4982fc8b6a72c9f706f < fd39c41bcd82d5ebaaebadb944eab5598c668a90affected
LinuxLinux6.13affected
LinuxLinux0 < 6.13unaffected
LinuxLinux6.13.3 <= 6.13.*unaffected
LinuxLinux6.14 <= *unaffected

Weaknesses

References