Description
In the Linux kernel, the following vulnerability has been resolved: cpufreq: intel_pstate: Fix crash during turbo disable When the system is booted with kernel command line argument "nosmt" or "maxcpus" to limit the number of CPUs, disabling turbo via: echo 1 > /sys/devices/system/cpu/intel_pstate/no_turbo results in a crash: PF: supervisor read access in kernel mode PF: error_code(0x0000) - not-present page PGD 0 P4D 0 Oops: Oops: 0000 [#1] SMP PTI ... RIP: 0010:store_no_turbo+0x100/0x1f0 ... This occurs because for_each_possible_cpu() returns CPUs even if they are not online. For those CPUs, all_cpu_data[] will be NULL. Since commit 973207ae3d7c ("cpufreq: intel_pstate: Rearrange max frequency updates handling code"), all_cpu_data[] is dereferenced even for CPUs which are not online, causing the NULL pointer dereference. To fix that, pass CPU number to intel_pstate_update_max_freq() and use all_cpu_data[] for those CPUs for which there is a valid cpufreq policy.
Product status
973207ae3d7c3c92df4a382df5d7bd695deaa904 (git) before a1850e2aef4d15405e7ff53fd51c4b3124d46182
973207ae3d7c3c92df4a382df5d7bd695deaa904 (git) before d20d48916ce8531b157c2edeba76d69af2974270
973207ae3d7c3c92df4a382df5d7bd695deaa904 (git) before 6b050482ec40569429d963ac52afa878691b04c9
6.16
Any version before 6.16
6.18.17 (semver)
6.19.7 (semver)
7.0 (original_commit_for_fix)
References
git.kernel.org/...c/a1850e2aef4d15405e7ff53fd51c4b3124d46182
git.kernel.org/...c/d20d48916ce8531b157c2edeba76d69af2974270
git.kernel.org/...c/6b050482ec40569429d963ac52afa878691b04c9