CVE-2021-47591

mptcp: remove tcp ulp setsockopt support

Description

In the Linux kernel, the following vulnerability has been resolved: mptcp: remove tcp ulp setsockopt support TCP_ULP setsockopt cannot be used for mptcp because its already used internally to plumb subflow (tcp) sockets to the mptcp layer. syzbot managed to trigger a crash for mptcp connections that are in fallback mode: KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027] CPU: 1 PID: 1083 Comm: syz-executor.3 Not tainted 5.16.0-rc2-syzkaller #0 RIP: 0010:tls_build_proto net/tls/tls_main.c:776 [inline] [..] __tcp_set_ulp net/ipv4/tcp_ulp.c:139 [inline] tcp_set_ulp+0x428/0x4c0 net/ipv4/tcp_ulp.c:160 do_tcp_setsockopt+0x455/0x37c0 net/ipv4/tcp.c:3391 mptcp_setsockopt+0x1b47/0x2400 net/mptcp/sockopt.c:638 Remove support for TCP_ULP setsockopt.

Category

5.5
CVSS
Severity: Medium
CVSS 3.1 •
EPSS 0.05%
Affected: Linux Linux
Affected: Linux Linux
Published at:
Updated at:

References

Link Tags
https://git.kernel.org/stable/c/3de0c86d42f841d1d64f316cd949e65c566f0734 patch
https://git.kernel.org/stable/c/404cd9a22150f24acf23a8df2ad0c094ba379f57 patch

Frequently Asked Questions

What is the severity of CVE-2021-47591?
CVE-2021-47591 has been scored as a medium severity vulnerability.
How to fix CVE-2021-47591?
To fix CVE-2021-47591, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2021-47591 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2021-47591 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2021-47591?
CVE-2021-47591 affects Linux Linux, Linux Linux.
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