CVE-2022-50332
What it is
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.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.1% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.1% in the next 30 days (EPSS).
- Severity: 5.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.1% · EPSS, next 30 days
- Record status
- Analyzed
Affected
- Linux Kernel < 6.0.6
Attack profile CVSS 3.1 · 5.5
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
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Read https://cve-list.com/agent/cve/CVE-2022-50332.md and follow it. Check whether this project is affected by CVE-2022-50332. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
