Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: powerpc/pseries: Rework lppaca_shared_proc() to avoid DEBUG_PREEMPT lppaca_shared_proc() takes a pointer to the lppaca which is typically accessed through get_lppaca(). With DEBUG_PREEMPT enabled, this leads to checking if preemption is enabled, for example: BUG: using smp_processor_id() in preemptible [00000000] code: grep/10693 caller is lparcfg_data+0x408/0x19a0 CPU: 4 PID: 10693 Comm: grep Not tainted 6.5.0-rc3 #2 Call Trace: dump_stack_lvl+0x154/0x200 (unreliable) check_preemption_disabled+0x214/0x220 lparcfg_data+0x408/0x19a0 ... This isn't actually a problem however, as it does not matter which lppaca is accessed, the shared proc state will be the same. vcpudispatch_stats_procfs_init() already works around this by disabling preemption, but the lparcfg code does not, erroring any time /proc/powerpc/lparcfg is accessed with DEBUG_PREEMPT enabled. Instead of disabling preemption on the caller side, rework lppaca_shared_proc() to not take a pointer and instead directly access the lppaca, bypassing any potential preemption checks. [mpe: Rework to avoid needing a definition in paca.h and lppaca.h]
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected f13c13a005127b5dc5daaca190277a062d946e63 before 953c54dfdc5d3eb7243ed902b50acb5ea1db4355; affected f13c13a005127b5dc5daaca190277a062d946e63 before 2935443dc9c28499223d8c881474259e4b998f2a; affected f13c13a005127b5dc5daaca190277a062d946e63 before 4c8568cf4c45b415854195c8832b557cdefba57a; affected f13c13a005127b5dc5daaca190277a062d946e63 before 3c5e8e666794d7dde6d14ea846c6c04f2bb34900; affected f13c13a005127b5dc5daaca190277a062d946e63 before f45ee5c074013a0fbfce77a5af5efddb01f5d4f4; affected f13c13a005127b5dc5daaca190277a062d946e63 before eac030b22ea12cdfcbb2e941c21c03964403c63f |
| Linux / Linux | affected 3.12; unaffected 0 before 3.12; unaffected 5.10.195 through 5.10.*; unaffected 5.15.132 through 5.15.*; unaffected 6.1.53 through 6.1.*; unaffected 6.4.16 through 6.4.*; unaffected 6.5.3 through 6.5.*; unaffected 6.6 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/953c54dfdc5d3eb7243ed902b50acb5ea1db4355
- https://git.kernel.org/stable/c/2935443dc9c28499223d8c881474259e4b998f2a
- https://git.kernel.org/stable/c/4c8568cf4c45b415854195c8832b557cdefba57a
- https://git.kernel.org/stable/c/3c5e8e666794d7dde6d14ea846c6c04f2bb34900
- https://git.kernel.org/stable/c/f45ee5c074013a0fbfce77a5af5efddb01f5d4f4
- https://git.kernel.org/stable/c/eac030b22ea12cdfcbb2e941c21c03964403c63f