| From bippy-5f407fcff5a0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: 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. |
| |
| The Linux kernel CVE team has assigned CVE-2021-47591 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.13 with commit d9e4c129181004ec94b315b0c9db5eeb09da75e6 and fixed in 5.15.11 with commit 3de0c86d42f841d1d64f316cd949e65c566f0734 |
| Issue introduced in 5.13 with commit d9e4c129181004ec94b315b0c9db5eeb09da75e6 and fixed in 5.16 with commit 404cd9a22150f24acf23a8df2ad0c094ba379f57 |
| |
| Please see https://www.kernel.org for a full list of currently supported |
| kernel versions by the kernel community. |
| |
| Unaffected versions might change over time as fixes are backported to |
| older supported kernel versions. The official CVE entry at |
| https://cve.org/CVERecord/?id=CVE-2021-47591 |
| will be updated if fixes are backported, please check that for the most |
| up to date information about this issue. |
| |
| |
| Affected files |
| ============== |
| |
| The file(s) affected by this issue are: |
| net/mptcp/sockopt.c |
| |
| |
| Mitigation |
| ========== |
| |
| The Linux kernel CVE team recommends that you update to the latest |
| stable kernel version for this, and many other bugfixes. Individual |
| changes are never tested alone, but rather are part of a larger kernel |
| release. Cherry-picking individual commits is not recommended or |
| supported by the Linux kernel community at all. If however, updating to |
| the latest release is impossible, the individual changes to resolve this |
| issue can be found at these commits: |
| https://git.kernel.org/stable/c/3de0c86d42f841d1d64f316cd949e65c566f0734 |
| https://git.kernel.org/stable/c/404cd9a22150f24acf23a8df2ad0c094ba379f57 |
