| 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-2021-47231: can: mcba_usb: fix memory leak in mcba_usb |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| can: mcba_usb: fix memory leak in mcba_usb |
| |
| Syzbot reported memory leak in SocketCAN driver for Microchip CAN BUS |
| Analyzer Tool. The problem was in unfreed usb_coherent. |
| |
| In mcba_usb_start() 20 coherent buffers are allocated and there is |
| nothing, that frees them: |
| |
| 1) In callback function the urb is resubmitted and that's all |
| 2) In disconnect function urbs are simply killed, but URB_FREE_BUFFER |
| is not set (see mcba_usb_start) and this flag cannot be used with |
| coherent buffers. |
| |
| Fail log: |
| | [ 1354.053291][ T8413] mcba_usb 1-1:0.0 can0: device disconnected |
| | [ 1367.059384][ T8420] kmemleak: 20 new suspected memory leaks (see /sys/kernel/debug/kmem) |
| |
| So, all allocated buffers should be freed with usb_free_coherent() |
| explicitly |
| |
| NOTE: |
| The same pattern for allocating and freeing coherent buffers |
| is used in drivers/net/can/usb/kvaser_usb/kvaser_usb_core.c |
| |
| The Linux kernel CVE team has assigned CVE-2021-47231 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.12 with commit 51f3baad7de943780ce0c17bd7975df567dd6e14 and fixed in 4.14.238 with commit 89df95ce32be204eef2e7d4b2f6fb552fb191a68 |
| Issue introduced in 4.12 with commit 51f3baad7de943780ce0c17bd7975df567dd6e14 and fixed in 4.19.196 with commit a115198caaab6d663bef75823a3c5f0802306d60 |
| Issue introduced in 4.12 with commit 51f3baad7de943780ce0c17bd7975df567dd6e14 and fixed in 5.4.128 with commit 6f87c0e21ad20dd3d22108e33db1c552dfa352a0 |
| Issue introduced in 4.12 with commit 51f3baad7de943780ce0c17bd7975df567dd6e14 and fixed in 5.10.46 with commit 6bd3d80d1f019cefa7011056c54b323f1d8b8e83 |
| Issue introduced in 4.12 with commit 51f3baad7de943780ce0c17bd7975df567dd6e14 and fixed in 5.12.13 with commit d0760a4ef85697bc756d06eae17ae27f3f055401 |
| Issue introduced in 4.12 with commit 51f3baad7de943780ce0c17bd7975df567dd6e14 and fixed in 5.13 with commit 91c02557174be7f72e46ed7311e3bea1939840b0 |
| |
| 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-2021-47231 |
| 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: |
| drivers/net/can/usb/mcba_usb.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/89df95ce32be204eef2e7d4b2f6fb552fb191a68 |
| https://git.kernel.org/stable/c/a115198caaab6d663bef75823a3c5f0802306d60 |
| https://git.kernel.org/stable/c/6f87c0e21ad20dd3d22108e33db1c552dfa352a0 |
| https://git.kernel.org/stable/c/6bd3d80d1f019cefa7011056c54b323f1d8b8e83 |
| https://git.kernel.org/stable/c/d0760a4ef85697bc756d06eae17ae27f3f055401 |
| https://git.kernel.org/stable/c/91c02557174be7f72e46ed7311e3bea1939840b0 |
