CVE-2019-19318

In the Linux kernel 5.3.11, mounting a crafted btrfs image twice can cause an rwsem_down_write_slowpath use-after-free because (in rwsem_can_spin_on_owner in kernel/locking/rwsem.c) rwsem_owner_flags returns an already freed pointer,

Weakness

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 Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00021.html
• https://github.com/bobfuzzer/CVE/tree/master/CVE-2019-19318
• https://lists.debian.org/debian-lts-announce/2021/03/msg00010.html
• https://security.netapp.com/advisory/ntap-20200103-0001/
• https://usn.ubuntu.com/4414-1/
• http://lists.opensuse.org/opensuse-security-announce/2020-03/msg00021.html
• https://github.com/bobfuzzer/CVE/tree/master/CVE-2019-19318
• https://lists.debian.org/debian-lts-announce/2021/03/msg00010.html
• https://security.netapp.com/advisory/ntap-20200103-0001/
• https://usn.ubuntu.com/4414-1/