| 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-2022-49669: mptcp: fix race on unaccepted mptcp sockets |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| mptcp: fix race on unaccepted mptcp sockets |
| |
| When the listener socket owning the relevant request is closed, |
| it frees the unaccepted subflows and that causes later deletion |
| of the paired MPTCP sockets. |
| |
| The mptcp socket's worker can run in the time interval between such delete |
| operations. When that happens, any access to msk->first will cause an UaF |
| access, as the subflow cleanup did not cleared such field in the mptcp |
| socket. |
| |
| Address the issue explicitly traversing the listener socket accept |
| queue at close time and performing the needed cleanup on the pending |
| msk. |
| |
| Note that the locking is a bit tricky, as we need to acquire the msk |
| socket lock, while still owning the subflow socket one. |
| |
| The Linux kernel CVE team has assigned CVE-2022-49669 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.17 with commit 86e39e04482b0aadf3ee3ed5fcf2d63816559d36 and fixed in 5.18.10 with commit a8a3e95c74e48c2c9b07b81fafda9122993f2e12 |
| Issue introduced in 5.17 with commit 86e39e04482b0aadf3ee3ed5fcf2d63816559d36 and fixed in 5.19 with commit 6aeed9045071f2252ff4e98fc13d1e304f33e5b0 |
| |
| 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-2022-49669 |
| 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/protocol.c |
| net/mptcp/protocol.h |
| net/mptcp/subflow.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/a8a3e95c74e48c2c9b07b81fafda9122993f2e12 |
| https://git.kernel.org/stable/c/6aeed9045071f2252ff4e98fc13d1e304f33e5b0 |
