CVE-2022-49353 powerpc/papr_scm: don't requests stats with '0' sized stats buffer
A missing check in the Linux kernel papr_scm driver causes a null pointer dereference and kernel panic when performance stats are disabled.
- 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-2022-49353?
CVE-2022-49353 is a medium-severity vulnerability in Linux kernel, published on 26 Feb 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:
powerpc/papr_scm: don't requests stats with '0' sized stats buffer
Sachin reported [1] that on a POWER-10 lpar he is seeing a kernel panic being reported with vPMEM when papr_scm probe is being called. The panic is of the form below and is observed only with following option disabled(profile) for the said LPAR 'Enable Performance Information Collection' in the HMC:
Kernel attempted to write user page (1c) - exploit attempt? (uid: 0) BUG: Kernel NULL pointer dereference on write at 0x0000001c Faulting instruction address: 0xc008000001b90844 Oops: Kernel access of bad area, sig: 11 [#1] <snip> NIP [c008000001b90844] drc_pmem_query_stats+0x5c/0x270 [papr_scm] LR [c008000001b92794] papr_scm_probe+0x2ac/0x6ec [papr_scm] Call Trace: 0xc00000000941bca0 (unreliable) papr_scm_probe+0x2ac/0x6ec [papr_scm] platform_probe+0x98/0x150 really_probe+0xfc/0x510 __driver_probe_device+0x17c/0x230 <snip> ---[ end trace 0000000000000000 ]--- Kernel panic - not syncing: Fatal exception
On investigation looks like this panic was caused due to a 'stat_buffer' of size==0 being provided to drc_pmem_query_stats() to fetch all performance stats-ids of an NVDIMM. However drc_pmem_query_stats() shouldn't have been called since the vPMEM NVDIMM doesn't support and performance stat-id's. This was caused due to missing check for 'p->stat_buffer_len' at the beginning of papr_scm_pmu_check_events() which indicates that the NVDIMM doesn't support performance-stats.
Fix this by introducing the check for 'p->stat_buffer_len' at the beginning of papr_scm_pmu_check_events().
[1] https://lore.kernel.org/all/[email protected]
Weakness: CWE-476
Which versions are affected by CVE-2022-49353?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2022-49353?
Apply the vendor's patch.
Is CVE-2022-49353 being exploited?
There is no known exploitation of CVE-2022-49353 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2022-49353, GHSA-6gv8-fgf9-gqgc, UBUNTU-CVE-2022-49353.