CVE-2022-49353
What it is
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]
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of 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
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Weakness
- CWE-476 · NULL pointer dereference
- Record status
- Modified
Affected
- Linux Kernel 5.18.3
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
Fix and advisories
- https://git.kernel.org/stable/c/07bf9431b1590d1cd7a8d62075d0b50b073f0495
- https://git.kernel.org/stable/c/e1295aab2ebcda1c1a9ed342baedc080e5c393e5