CVE-2022-50103
What it is
In the Linux kernel, the following vulnerability has been resolved: sched, cpuset: Fix dl_cpu_busy() panic due to empty cs->cpus_allowed With cgroup v2, the cpuset's cpus_allowed mask can be empty indicating that the cpuset will just use the effective CPUs of its parent. So cpuset_can_attach() can call task_can_attach() with an empty mask. This can lead to cpumask_any_and() returns nr_cpu_ids causing the call to dl_bw_of() to crash due to percpu value access of an out of bound CPU value. For example: [80468.182258] BUG: unable to handle page fault for address: ffffffff8b6648b0 : [80468.191019] RIP: 0010:dl_cpu_busy+0x30/0x2b0 : [80468.207946] Call Trace: [80468.208947] cpuset_can_attach+0xa0/0x140 [80468.209953] cgroup_migrate_execute+0x8c/0x490 [80468.210931] cgroup_update_dfl_csses+0x254/0x270 [80468.211898] cgroup_subtree_control_write+0x322/0x400 [80468.212854] kernfs_fop_write_iter+0x11c/0x1b0 [80468.213777] new_sync_write+0x11f/0x1b0 [80468.214689] vfs_write+0x1eb/0x280 [80468.215592] ksys_write+0x5f/0xe0 [80468.216463] do_syscall_64+0x5c/0x80 [80468.224287] entry_SYSCALL_64_after_hwframe+0x44/0xae Fix that by using effective_cpus instead. For cgroup v1, effective_cpus is the same as cpus_allowed. For v2, effective_cpus is the real cpumask to be used by tasks within the cpuset anyway. Also update task_can_attach()'s 2nd argument name to cs_effective_cpus to reflect the change. In addition, a check is added to task_can_attach() to guard against the possibility that cpumask_any_and() may return a value >= nr_cpu_ids.
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of data exposure, service disruption.
- Exploit odds
- 0.2% 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: 0.2% in the next 30 days (EPSS).
- Severity: 7.1 HIGH (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Weakness
- CWE-125 · Out-of-bounds read
- Record status
- Analyzed
Affected
- Linux Kernel < 5.10.137
- Linux Kernel < 5.15.61
- Linux Kernel < 5.18.18
- Linux Kernel < 5.19.2
Attack profile CVSS 3.1 · 7.1
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2022-50103.md and follow it. Check whether this project is affected by CVE-2022-50103. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://git.kernel.org/stable/c/147f66d22f58712dce7ccdd6a1f6cb3ee8042df4
- https://git.kernel.org/stable/c/336626564b58071b8980a4e6a31a8f5d92705d9b
- https://git.kernel.org/stable/c/357f3f0e522a6ce1ce4a571cb780d9861d53bec7
- https://git.kernel.org/stable/c/b6e8d40d43ae4dec00c8fea2593eeea3114b8f44
- https://git.kernel.org/stable/c/f56607b44c9896e51678a7e8cdd3a5479f4b4548
References
- https://git.kernel.org/stable/c/147f66d22f58712dce7ccdd6a1f6cb3ee8042df4
- https://git.kernel.org/stable/c/336626564b58071b8980a4e6a31a8f5d92705d9b
- https://git.kernel.org/stable/c/357f3f0e522a6ce1ce4a571cb780d9861d53bec7
- https://git.kernel.org/stable/c/b6e8d40d43ae4dec00c8fea2593eeea3114b8f44
- https://git.kernel.org/stable/c/f56607b44c9896e51678a7e8cdd3a5479f4b4548