Bug 2395788 (CVE-2025-39807) - CVE-2025-39807 kernel: drm/mediatek: Add error handling for old state CRTC in atomic_disable
Summary: CVE-2025-39807 kernel: drm/mediatek: Add error handling for old state CRTC in...
Keywords:
Status: NEW
Alias: CVE-2025-39807
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
unspecified
unspecified
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2025-09-16 14:02 UTC by OSIDB Bzimport
Modified: 2025-11-26 09:39 UTC (History)
0 users

Fixed In Version:
Clone Of:
Environment:
Last Closed:
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Description OSIDB Bzimport 2025-09-16 14:02:30 UTC
In the Linux kernel, the following vulnerability has been resolved:

drm/mediatek: Add error handling for old state CRTC in atomic_disable

Introduce error handling to address an issue where, after a hotplug
event, the cursor continues to update. This situation can lead to a
kernel panic due to accessing the NULL `old_state->crtc`.

E,g.
Unable to handle kernel NULL pointer dereference at virtual address
Call trace:
 mtk_crtc_plane_disable+0x24/0x140
 mtk_plane_atomic_update+0x8c/0xa8
 drm_atomic_helper_commit_planes+0x114/0x2c8
 drm_atomic_helper_commit_tail_rpm+0x4c/0x158
 commit_tail+0xa0/0x168
 drm_atomic_helper_commit+0x110/0x120
 drm_atomic_commit+0x8c/0xe0
 drm_atomic_helper_update_plane+0xd4/0x128
 __setplane_atomic+0xcc/0x110
 drm_mode_cursor_common+0x250/0x440
 drm_mode_cursor_ioctl+0x44/0x70
 drm_ioctl+0x264/0x5d8
 __arm64_sys_ioctl+0xd8/0x510
 invoke_syscall+0x6c/0xe0
 do_el0_svc+0x68/0xe8
 el0_svc+0x34/0x60
 el0t_64_sync_handler+0x1c/0xf8
 el0t_64_sync+0x180/0x188

Adding NULL pointer checks to ensure stability by preventing operations
on an invalid CRTC state.


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