In the Linux kernel 5.4.0-rc2, there is a use-after-free (read) in the __blk_add_trace function in kernel/trace/blktrace.c (which is used to fill out a blk_io_trace structure and place it in a per-cpu sub-buffer).
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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.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.kernel.org/show_bug.cgi?id=205711 | issue tracking vendor advisory |
| https://security.netapp.com/advisory/ntap-20200103-0001/ | |
| http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00039.html | vendor advisory |
| https://usn.ubuntu.com/4344-1/ | vendor advisory |
| https://usn.ubuntu.com/4345-1/ | vendor advisory |
| https://usn.ubuntu.com/4342-1/ | vendor advisory |
| https://usn.ubuntu.com/4346-1/ | vendor advisory |
| https://lists.debian.org/debian-lts-announce/2020/06/msg00011.html | mailing list |
| https://lists.debian.org/debian-lts-announce/2020/06/msg00012.html | mailing list |
| https://lists.debian.org/debian-lts-announce/2020/06/msg00013.html | mailing list |
| https://www.debian.org/security/2020/dsa-4698 | vendor advisory |