| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2025-21747: drm/ast: astdp: Fix timeout for enabling video signal |
| |
| 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. |
| |
| The Linux kernel CVE team has assigned CVE-2025-21747 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.13 with commit 4e29cc7c5c673299cfbaf4982fc8b6a72c9f706f and fixed in 6.13.3 with commit 589839379031cce220c9cab9f27cb5477195067e |
| Issue introduced in 6.13 with commit 4e29cc7c5c673299cfbaf4982fc8b6a72c9f706f and fixed in 6.14 with commit fd39c41bcd82d5ebaaebadb944eab5598c668a90 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2025-21747 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| drivers/gpu/drm/ast/ast_dp.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/589839379031cce220c9cab9f27cb5477195067e |
| https://git.kernel.org/stable/c/fd39c41bcd82d5ebaaebadb944eab5598c668a90 |
