cbcvebase.
CVE-2021-47318
published 2024-05-21

CVE-2021-47318: In the Linux kernel, the following vulnerability has been resolved: arch_topology: Avoid use-after-free for scale_freq_data Currently…

PriorityP338high7.8CVSS 3.1
AVLACLPRLUINSUCHIHAH
EPSS
0.23%
13.9th percentile
In the Linux kernel, the following vulnerability has been resolved: arch_topology: Avoid use-after-free for scale_freq_data Currently topology_scale_freq_tick() (which gets called from scheduler_tick()) may end up using a pointer to "struct scale_freq_data", which was previously cleared by topology_clear_scale_freq_source(), as there is no protection in place here. The users of topology_clear_scale_freq_source() though needs a guarantee that the previously cleared scale_freq_data isn't used anymore, so they can free the related resources. Since topology_scale_freq_tick() is called from scheduler tick, we don't want to add locking in there. Use the RCU update mechanism instead (which is already used by the scheduler's utilization update path) to guarantee race free updates here. synchronize_rcu() makes sure that all RCU critical sections that started before it is called, will finish before it returns. And so the callers of topology_clear_scale_freq_source() don't need to worry about their callback getting called anymore.

Affected

8 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 5.14.6-1 (bookworm)linux 5.14.6-1 (bookworm)
linuxlinux
linuxlinux>= 01e055c120a46e78650b5f903088badbbdaae9ad < ccdf7e073170886bc370c613e269de610a794c4accdf7e073170886bc370c613e269de610a794c4a
linuxlinux>= 01e055c120a46e78650b5f903088badbbdaae9ad < 83150f5d05f065fb5c12c612f119015cabdcc12483150f5d05f065fb5c12c612f119015cabdcc124
linuxlinux_kernel>= 0 < 5.14.6-15.14.6-1
linuxlinux_kernel>= 0 < 5.14.6-15.14.6-1
linuxlinux_kernel>= 0 < 5.14.6-15.14.6-1
linuxlinux_kernel>= 5.13 < 5.13.45.13.4

CVSS provenance

nvdv3.17.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
osv7.8HIGH
vendor_debian7.8HIGH
vendor_redhat7.8HIGH
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