Description
In the Linux kernel, the following vulnerability has been resolved: cgroup/cpuset: rebind mm mempolicy to effective_mems, not mems_allowed Creating a child cpuset where cpuset.mems is never set leads to a div/0 when a VMA mempolicy with MPOL_F_RELATIVE_NODES rebinds in response to a CPU hotplug event. Reproduction steps: 1) Create a cgroup w/ cpuset controls (do not set cpuset.mems) 2) Move the task into the child cpuset 3) Create a VMA mempolicy for that task with MPOL_F_RELATIVE_NODES 4) unplug and hotplug a cpu echo 0 > /sys/devices/system/cpu/cpu1/online echo 1 > /sys/devices/system/cpu/cpu1/online 5) mempolicy rebind does a div/0 in mpol_relative_nodemask on the call to __nodes_fold() The cpuset code passes (cs->mems_allowed) which is not guaranteed to have nodes to the rebind routine. Use cs->effective_mems instead, which is guaranteed to have a non-empty nodemask once we reach that code path. [ david: add a comment, slightly rephrase description ]
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
ae1c802382f7af60aa54879fb4f5920a9df1ff48 to < b7adeba2a21c98c7b20f18e27e3ead86bdb5e08daffectedae1c802382f7af60aa54879fb4f5920a9df1ff48 to < fcc8c310539c3cc523419113b227161a96b50550affectedae1c802382f7af60aa54879fb4f5920a9df1ff48 to < 4b06449384b9ee5b3372bab60601ba5cd4162086affectedae1c802382f7af60aa54879fb4f5920a9df1ff48 to < 02f67c4f88be8e3dbd91951d13cdcc5bcc82e9c7affectedae1c802382f7af60aa54879fb4f5920a9df1ff48 to < fc680afc510157f6b137956011c09abc23eb0842affectedae1c802382f7af60aa54879fb4f5920a9df1ff48 to < c844b7d9a9586de15dd28c06da5cc7f6ab28787daffectedae1c802382f7af60aa54879fb4f5920a9df1ff48 to < c17f06d8a085d6be58b544a440ce243f5e441a60affectedae1c802382f7af60aa54879fb4f5920a9df1ff48 to < b983c56426383e4a06fa5970c4e33cee879b1482affected
Linux Linux
Default version status: affected
3.17affected0 to < 3.17unaffected5.10.261 to ≤ 5.10.*unaffected5.15.212 to ≤ 5.15.*unaffected6.1.178 to ≤ 6.1.*unaffected6.6.145 to ≤ 6.6.*unaffected6.12.97 to ≤ 6.12.*unaffected6.18.40 to ≤ 6.18.*unaffected7.1.5 to ≤ 7.1.*unaffected7.2 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/b7adeba2a21c98c7b20f18e27e3ead86bdb5e08d ↗
- https://git.kernel.org/stable/c/fcc8c310539c3cc523419113b227161a96b50550 ↗
- https://git.kernel.org/stable/c/4b06449384b9ee5b3372bab60601ba5cd4162086 ↗
- https://git.kernel.org/stable/c/02f67c4f88be8e3dbd91951d13cdcc5bcc82e9c7 ↗
- https://git.kernel.org/stable/c/fc680afc510157f6b137956011c09abc23eb0842 ↗
- https://git.kernel.org/stable/c/c844b7d9a9586de15dd28c06da5cc7f6ab28787d ↗
- https://git.kernel.org/stable/c/c17f06d8a085d6be58b544a440ce243f5e441a60 ↗
- https://git.kernel.org/stable/c/b983c56426383e4a06fa5970c4e33cee879b1482 ↗