Description: use-after-free in io_uring feature
References:
 https://www.zerodayinitiative.com/advisories/ZDI-21-001/
 https://www.openwall.com/lists/oss-security/2021/02/05/4
 https://bugzilla.redhat.com/show_bug.cgi?id=1873476
 https://www.openwall.com/lists/oss-security/2021/02/05/7
 https://bugzilla.suse.com/show_bug.cgi?id=1180564#c11
Notes:
 carnil> Claimed to be fixed in 5.10.2, but this cannot be the right
 carnil> version as there were no changes in 5.10.1 to 5.10.2 in
 carnil> io_uring. The Red Hat bugzilla entry has little more details.
 carnil> Possibly as well just a duplicate of CVE-2020-29534 and would
 carnil> thus be fixed earlier already for the sid branch (See SUSE
 carnil> bugzilla bug).
Bugs:
upstream: released (5.10-rc1) [233295130e53c8dfe6dbef3f52634c3f7e44cd6a]
5.10-upstream-stable: N/A "Fixed before branching point"
4.19-upstream-stable: N/A "Vulnerable code introduced later"
4.9-upstream-stable: N/A "Vulnerable code introduced later"
sid: released (5.10.4-1)
4.19-buster-security: N/A "Vulnerable code introduced later"
4.9-stretch-security: N/A "Vulnerable code introduced later"