Description
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]
Product status
f13c13a005127b5dc5daaca190277a062d946e63 (git) before 953c54dfdc5d3eb7243ed902b50acb5ea1db4355
f13c13a005127b5dc5daaca190277a062d946e63 (git) before 2935443dc9c28499223d8c881474259e4b998f2a
f13c13a005127b5dc5daaca190277a062d946e63 (git) before 4c8568cf4c45b415854195c8832b557cdefba57a
f13c13a005127b5dc5daaca190277a062d946e63 (git) before 3c5e8e666794d7dde6d14ea846c6c04f2bb34900
f13c13a005127b5dc5daaca190277a062d946e63 (git) before f45ee5c074013a0fbfce77a5af5efddb01f5d4f4
f13c13a005127b5dc5daaca190277a062d946e63 (git) before eac030b22ea12cdfcbb2e941c21c03964403c63f
3.12
Any version before 3.12
5.10.195 (semver)
5.15.132 (semver)
6.1.53 (semver)
6.4.16 (semver)
6.5.3 (semver)
6.6 (original_commit_for_fix)
References
git.kernel.org/...c/953c54dfdc5d3eb7243ed902b50acb5ea1db4355
git.kernel.org/...c/2935443dc9c28499223d8c881474259e4b998f2a
git.kernel.org/...c/4c8568cf4c45b415854195c8832b557cdefba57a
git.kernel.org/...c/3c5e8e666794d7dde6d14ea846c6c04f2bb34900
git.kernel.org/...c/f45ee5c074013a0fbfce77a5af5efddb01f5d4f4
git.kernel.org/...c/eac030b22ea12cdfcbb2e941c21c03964403c63f
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