In the Linux kernel 4.19.83, there is a use-after-free (read) in the debugfs_remove function in fs/debugfs/inode.c (which is used to remove a file or directory in debugfs that was previously created with a call to another debugfs function such as debugfs_create_file). NOTE: Linux kernel developers dispute this issue as not being an issue with debugfs, instead this is an issue with misuse of debugfs within blktrace
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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.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=205713 | issue tracking exploit vendor advisory |
| https://security.netapp.com/advisory/ntap-20200103-0001/ | third party advisory |
| https://lore.kernel.org/linux-block/20200402000002.7442-1-mcgrof%40kernel.org/ | |
| http://lists.opensuse.org/opensuse-security-announce/2020-04/msg00035.html | vendor advisory |
| https://lists.debian.org/debian-lts-announce/2020/12/msg00015.html | mailing list |