The Linux kernel 4.9.x before 4.9.233, 4.14.x before 4.14.194, and 4.19.x before 4.19.140 has a use-after-free because skcd->no_refcnt was not considered during a backport of a CVE-2020-14356 patch. This is related to the cgroups feature.
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.
| Link | Tags |
|---|---|
| https://bugzilla.redhat.com/show_bug.cgi?id=1868453 | issue tracking third party advisory patch |
| https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=linux-4.14.y&id=82fd2138a5ffd7e0d4320cdb669e115ee976a26e | issue tracking patch vendor advisory |
| https://www.spinics.net/lists/stable/msg405099.html | mailing list third party advisory patch |
| https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.233 | release notes vendor advisory |
| https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.194 | release notes vendor advisory |
| https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.140 | release notes vendor advisory |
| https://security.netapp.com/advisory/ntap-20201001-0004/ | third party advisory |
| https://lists.debian.org/debian-lts-announce/2020/10/msg00032.html | third party advisory mailing list |
| https://lists.debian.org/debian-lts-announce/2020/10/msg00034.html | third party advisory mailing list |