CVE-2022-50332 video/aperture: Call sysfb_disable() before removing PCI devices
A race condition in the Linux kernel video aperture driver allows simpledrm to interfere with hardware drivers, causing system hangs and denial of service.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-50332?
CVE-2022-50332 is a medium-severity vulnerability in Linux kernel, published on 15 Sep 2025. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
video/aperture: Call sysfb_disable() before removing PCI devices
Call sysfb_disable() from aperture_remove_conflicting_pci_devices() before removing PCI devices. Without, simpledrm can still bind to simple-framebuffer devices after the hardware driver has taken over the hardware. Both drivers interfere with each other and results are undefined.
Reported modesetting errors [1] are shown below.
---- snap ---- rcu: INFO: rcu_sched detected expedited stalls on CPUs/tasks: { 13-.... } 7 jiffies s: 165 root: 0x2000/. rcu: blocking rcu_node structures (internal RCU debug): Task dump for CPU 13: task:X state:R running task stack: 0 pid: 4242 ppid: 4228 flags:0x00000008 Call Trace: <TASK> ? commit_tail+0xd7/0x130 ? drm_atomic_helper_commit+0x126/0x150 ? drm_atomic_commit+0xa4/0xe0 ? drm_plane_get_damage_clips.cold+0x1c/0x1c ? drm_atomic_helper_dirtyfb+0x19e/0x280 ? drm_mode_dirtyfb_ioctl+0x10f/0x1e0 ? drm_mode_getfb2_ioctl+0x2d0/0x2d0 ? drm_ioctl_kernel+0xc4/0x150 ? drm_ioctl+0x246/0x3f0 ? drm_mode_getfb2_ioctl+0x2d0/0x2d0 ? __x64_sys_ioctl+0x91/0xd0 ? do_syscall_64+0x60/0xd0 ? entry_SYSCALL_64_after_hwframe+0x4b/0xb5 </TASK> ... rcu: INFO: rcu_sched detected expedited stalls on CPUs/tasks: { 13-.... } 30 jiffies s: 169 root: 0x2000/. rcu: blocking rcu_node structures (internal RCU debug): Task dump for CPU 13: task:X state:R running task stack: 0 pid: 4242 ppid: 4228 flags:0x0000400e Call Trace: <TASK> ? memcpy_toio+0x76/0xc0 ? memcpy_toio+0x1b/0xc0 ? drm_fb_memcpy_toio+0x76/0xb0 ? drm_fb_blit_toio+0x75/0x2b0 ? simpledrm_simple_display_pipe_update+0x132/0x150 ? drm_atomic_helper_commit_planes+0xb6/0x230 ? drm_atomic_helper_commit_tail+0x44/0x80 ? commit_tail+0xd7/0x130 ? drm_atomic_helper_commit+0x126/0x150 ? drm_atomic_commit+0xa4/0xe0 ? drm_plane_get_damage_clips.cold+0x1c/0x1c ? drm_atomic_helper_dirtyfb+0x19e/0x280 ? drm_mode_dirtyfb_ioctl+0x10f/0x1e0 ? drm_mode_getfb2_ioctl+0x2d0/0x2d0 ? drm_ioctl_kernel+0xc4/0x150 ? drm_ioctl+0x246/0x3f0 ? drm_mode_getfb2_ioctl+0x2d0/0x2d0 ? __x64_sys_ioctl+0x91/0xd0 ? do_syscall_64+0x60/0xd0 ? entry_SYSCALL_64_after_hwframe+0x4b/0xb5 </TASK>
The problem was added by commit 5e0137612430 ("video/aperture: Disable and unregister sysfb devices via aperture helpers") to v6.0.3 and does not exist in the mainline branch.
The mainline commit 5e0137612430 ("video/aperture: Disable and unregister sysfb devices via aperture helpers") has been backported from v6.0-rc1 to stable v6.0.3 from a larger patch series [2] that reworks fbdev framebuffer ownership. The backport misses a change to aperture_remove_conflicting_pci_devices(). Mainline itself is fine, because the function does not exist there as a result of the patch series.
Instead of backporting the whole series, fix the additional function.
Which versions are affected by CVE-2022-50332?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-50332?
Apply the vendor's patch.
Is CVE-2022-50332 being exploited?
There is no known exploitation of CVE-2022-50332 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-50332, GHSA-422j-5566-qw87, ROOT-OS-UBUNTU-2204-CVE-2022-50332, ROOT-OS-UBUNTU-2404-CVE-2022-50332, UBUNTU-CVE-2022-50332.