A flaw use-after-free in function sco_sock_sendmsg() of the Linux kernel HCI subsystem was found in the way user calls ioct UFFDIO_REGISTER or other way triggers race condition of the call sco_conn_del() together with the call sco_sock_sendmsg() with the expected controllable faulting memory page. A privileged local user could use this flaw to crash the system or escalate their privileges on the system.
The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.
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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.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=1980646 | patch third party advisory issue tracking |
| https://ubuntu.com/security/CVE-2021-3640 | third party advisory patch |
| https://www.openwall.com/lists/oss-security/2021/07/22/1 | mailing list third party advisory exploit |
| https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/net/bluetooth/sco.c?h=v5.16&id=99c23da0eed4fd20cae8243f2b51e10e66aa0951 | patch vendor advisory |
| https://github.com/torvalds/linux/commit/99c23da0eed4fd20cae8243f2b51e10e66aa0951 | third party advisory patch |
| https://lists.debian.org/debian-lts-announce/2022/03/msg00011.html | third party advisory mailing list |
| https://lists.debian.org/debian-lts-announce/2022/03/msg00012.html | third party advisory mailing list |
| https://www.debian.org/security/2022/dsa-5096 | third party advisory vendor advisory |
| https://security.netapp.com/advisory/ntap-20220419-0003/ | third party advisory |