Description (CNA)
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 (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected ae1c802382f7af60aa54879fb4f5920a9df1ff48 before b7adeba2a21c98c7b20f18e27e3ead86bdb5e08d; affected ae1c802382f7af60aa54879fb4f5920a9df1ff48 before fcc8c310539c3cc523419113b227161a96b50550; affected ae1c802382f7af60aa54879fb4f5920a9df1ff48 before 4b06449384b9ee5b3372bab60601ba5cd4162086; affected ae1c802382f7af60aa54879fb4f5920a9df1ff48 before 02f67c4f88be8e3dbd91951d13cdcc5bcc82e9c7; affected ae1c802382f7af60aa54879fb4f5920a9df1ff48 before fc680afc510157f6b137956011c09abc23eb0842; affected ae1c802382f7af60aa54879fb4f5920a9df1ff48 before c844b7d9a9586de15dd28c06da5cc7f6ab28787d; affected ae1c802382f7af60aa54879fb4f5920a9df1ff48 before c17f06d8a085d6be58b544a440ce243f5e441a60; affected ae1c802382f7af60aa54879fb4f5920a9df1ff48 before b983c56426383e4a06fa5970c4e33cee879b1482 |
| Linux / Linux | affected 3.17; unaffected 0 before 3.17; unaffected 5.10.261 through 5.10.*; unaffected 5.15.212 through 5.15.*; unaffected 6.1.178 through 6.1.*; unaffected 6.6.145 through 6.6.*; unaffected 6.12.97 through 6.12.*; unaffected 6.18.40 through 6.18.*; unaffected 7.1.5 through 7.1.*; unaffected 7.2 through * |
CWE
No CWE identifiers supplied.
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