| 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-2022-49149: rxrpc: Fix call timer start racing with call destruction |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| rxrpc: Fix call timer start racing with call destruction |
| |
| The rxrpc_call struct has a timer used to handle various timed events |
| relating to a call. This timer can get started from the packet input |
| routines that are run in softirq mode with just the RCU read lock held. |
| Unfortunately, because only the RCU read lock is held - and neither ref or |
| other lock is taken - the call can start getting destroyed at the same time |
| a packet comes in addressed to that call. This causes the timer - which |
| was already stopped - to get restarted. Later, the timer dispatch code may |
| then oops if the timer got deallocated first. |
| |
| Fix this by trying to take a ref on the rxrpc_call struct and, if |
| successful, passing that ref along to the timer. If the timer was already |
| running, the ref is discarded. |
| |
| The timer completion routine can then pass the ref along to the call's work |
| item when it queues it. If the timer or work item where already |
| queued/running, the extra ref is discarded. |
| |
| The Linux kernel CVE team has assigned CVE-2022-49149 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.15 with commit a158bdd3247b9656df36ba133235fff702e9fdc3 and fixed in 5.10.110 with commit 051360e51341cd17738d82c15a8226010c7cb7f6 |
| Issue introduced in 4.15 with commit a158bdd3247b9656df36ba133235fff702e9fdc3 and fixed in 5.15.33 with commit 8cbf4ae7a2833767d63114573e5f9a45740cc975 |
| Issue introduced in 4.15 with commit a158bdd3247b9656df36ba133235fff702e9fdc3 and fixed in 5.16.19 with commit 54df5a37f1d951ed27fd47bf9b15a42279582110 |
| Issue introduced in 4.15 with commit a158bdd3247b9656df36ba133235fff702e9fdc3 and fixed in 5.17.2 with commit 5e3c11144e557a9dbf9a2f6abe444689ef9d8aae |
| Issue introduced in 4.15 with commit a158bdd3247b9656df36ba133235fff702e9fdc3 and fixed in 5.18 with commit 4a7f62f91933c8ae5308f9127fd8ea48188b6bc3 |
| |
| 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-2022-49149 |
| 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: |
| include/trace/events/rxrpc.h |
| net/rxrpc/ar-internal.h |
| net/rxrpc/call_event.c |
| net/rxrpc/call_object.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/051360e51341cd17738d82c15a8226010c7cb7f6 |
| https://git.kernel.org/stable/c/8cbf4ae7a2833767d63114573e5f9a45740cc975 |
| https://git.kernel.org/stable/c/54df5a37f1d951ed27fd47bf9b15a42279582110 |
| https://git.kernel.org/stable/c/5e3c11144e557a9dbf9a2f6abe444689ef9d8aae |
| https://git.kernel.org/stable/c/4a7f62f91933c8ae5308f9127fd8ea48188b6bc3 |
