CVE-2022-49955
- Source
- https://cve.org/CVERecord?id=CVE-2022-49955
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2022-49955.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2022-49955
- Downstream
- Published
- 2025-06-18T11:00:17Z
- Modified
- 2026-10-20T10:57:42Z
- Summary
- powerpc/rtas: Fix RTAS MSR[HV] handling for Cell
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
powerpc/rtas: Fix RTAS MSR[HV] handling for Cell
The semi-recent changes to MSR handling when entering RTAS (firmware) cause crashes on IBM Cell machines. An example trace:
kernel tried to execute user page (2fff01a8) - exploit attempt? (uid: 0) BUG: Unable to handle kernel instruction fetch Faulting instruction address: 0x2fff01a8 Oops: Kernel access of bad area, sig: 11 [#1] BE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=4 NUMA Cell Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Tainted: G W 6.0.0-rc2-00433-gede0a8d3307a #207 NIP: 000000002fff01a8 LR: 0000000000032608 CTR: 0000000000000000 REGS: c0000000015236b0 TRAP: 0400 Tainted: G W (6.0.0-rc2-00433-gede0a8d3307a) MSR: 0000000008001002 <ME,RI> CR: 00000000 XER: 20000000 ... NIP 0x2fff01a8 LR 0x32608 Call Trace: 0xc00000000143c5f8 (unreliable) .rtas_call+0x224/0x320 .rtas_get_boot_time+0x70/0x150 .read_persistent_clock64+0x114/0x140 .read_persistent_wall_and_boot_offset+0x24/0x80 .timekeeping_init+0x40/0x29c .start_kernel+0x674/0x8f0 start_here_common+0x1c/0x50
Unlike PAPR platforms where RTAS is only used in guests, on the IBM Cell machines Linux runs with MSR[HV] set but also uses RTAS, provided by SLOF.
Fix it by copying the MSR[HV] bit from the MSR value we've just read using mfmsr into the value used for RTAS.
It seems like we could also fix it using an #ifdef CELL to set MSR[HV], but that doesn't work because it's possible to build a single kernel image that runs on both Cell native and pseries.
- Database specific
{ "cna_assigner": "Linux", "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/49xxx/CVE-2022-49955.json" }- References
-
- https://git.kernel.org/stable/c/8b08d4f97233d8e58fff2fd9d5f86397a49733c5
- https://git.kernel.org/stable/c/91926d8b7e71aaf5f84f0cf208fc5a8b7a761050
- https://github.com/CVEProject/cvelistV5/tree/main/cves/2022/49xxx/CVE-2022-49955.json
- https://nvd.nist.gov/vuln/detail/CVE-2022-49955
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected packages
Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected ranges
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedb6b1c3ce06ca438eb24e0f45bf0e63ecad0369f5Fixed8b08d4f97233d8e58fff2fd9d5f86397a49733c5Fixed91926d8b7e71aaf5f84f0cf208fc5a8b7a761050
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced5.15.46Fixed5.16
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced5.17.14Fixed5.18
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced5.18.3Fixed5.19
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced5ca40fcf0da0ce2b5bc44e7d8b036535955f2e3d
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced5f4367448f6817c8a0e94dc9736ed84fa8eee4a3
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedc9c41f0273826a13ac93124e66a4ff45df281ba0