| 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-2022-49755: usb: gadget: f_fs: Prevent race during ffs_ep0_queue_wait |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| usb: gadget: f_fs: Prevent race during ffs_ep0_queue_wait |
| |
| While performing fast composition switch, there is a possibility that the |
| process of ffs_ep0_write/ffs_ep0_read get into a race condition |
| due to ep0req being freed up from functionfs_unbind. |
| |
| Consider the scenario that the ffs_ep0_write calls the ffs_ep0_queue_wait |
| by taking a lock &ffs->ev.waitq.lock. However, the functionfs_unbind isn't |
| bounded so it can go ahead and mark the ep0req to NULL, and since there |
| is no NULL check in ffs_ep0_queue_wait we will end up in use-after-free. |
| |
| Fix this by making a serialized execution between the two functions using |
| a mutex_lock(ffs->mutex). |
| |
| The Linux kernel CVE team has assigned CVE-2022-49755 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 2.6.35 with commit ddf8abd2599491cbad959c700b90ba72a5dce8d0 and fixed in 4.14.305 with commit facf353c9e8d7885b686d9a4b173d4e0af6441d2 |
| Issue introduced in 2.6.35 with commit ddf8abd2599491cbad959c700b90ba72a5dce8d0 and fixed in 4.19.272 with commit e9036e951f93fb8d7b5e9d6e2c7f94a4da312ae4 |
| Issue introduced in 2.6.35 with commit ddf8abd2599491cbad959c700b90ba72a5dce8d0 and fixed in 5.4.231 with commit a8d40942df074f4ebcb9bd3413596d92f323b064 |
| Issue introduced in 2.6.35 with commit ddf8abd2599491cbad959c700b90ba72a5dce8d0 and fixed in 5.10.166 with commit 6dd9ea05534f323668db94fcc2726c7a84547e78 |
| Issue introduced in 2.6.35 with commit ddf8abd2599491cbad959c700b90ba72a5dce8d0 and fixed in 5.15.91 with commit ae8e136bcaae96163b5821984de1036efc9abb1a |
| Issue introduced in 2.6.35 with commit ddf8abd2599491cbad959c700b90ba72a5dce8d0 and fixed in 6.1.9 with commit 6aee197b7fbcd61596a78b47d553f2f99111f217 |
| Issue introduced in 2.6.35 with commit ddf8abd2599491cbad959c700b90ba72a5dce8d0 and fixed in 6.2 with commit 6a19da111057f69214b97c62fb0ac59023970850 |
| |
| 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-2022-49755 |
| 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/usb/gadget/function/f_fs.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/facf353c9e8d7885b686d9a4b173d4e0af6441d2 |
| https://git.kernel.org/stable/c/e9036e951f93fb8d7b5e9d6e2c7f94a4da312ae4 |
| https://git.kernel.org/stable/c/a8d40942df074f4ebcb9bd3413596d92f323b064 |
| https://git.kernel.org/stable/c/6dd9ea05534f323668db94fcc2726c7a84547e78 |
| https://git.kernel.org/stable/c/ae8e136bcaae96163b5821984de1036efc9abb1a |
| https://git.kernel.org/stable/c/6aee197b7fbcd61596a78b47d553f2f99111f217 |
| https://git.kernel.org/stable/c/6a19da111057f69214b97c62fb0ac59023970850 |
