| 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-2022-49393: misc: fastrpc: fix list iterator in fastrpc_req_mem_unmap_impl |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| misc: fastrpc: fix list iterator in fastrpc_req_mem_unmap_impl |
| |
| This is another instance of incorrect use of list iterator and |
| checking it for NULL. |
| |
| The list iterator value 'map' will *always* be set and non-NULL |
| by list_for_each_entry(), so it is incorrect to assume that the |
| iterator value will be NULL if the list is empty (in this case, the |
| check 'if (!map) {' will always be false and never exit as expected). |
| |
| To fix the bug, use a new variable 'iter' as the list iterator, |
| while use the original variable 'map' as a dedicated pointer to |
| point to the found element. |
| |
| Without this patch, Kernel crashes with below trace: |
| |
| Unable to handle kernel access to user memory outside uaccess routines |
| at virtual address 0000ffff7fb03750 |
| ... |
| Call trace: |
| fastrpc_map_create+0x70/0x290 [fastrpc] |
| fastrpc_req_mem_map+0xf0/0x2dc [fastrpc] |
| fastrpc_device_ioctl+0x138/0xc60 [fastrpc] |
| __arm64_sys_ioctl+0xa8/0xec |
| invoke_syscall+0x48/0x114 |
| el0_svc_common.constprop.0+0xd4/0xfc |
| do_el0_svc+0x28/0x90 |
| el0_svc+0x3c/0x130 |
| el0t_64_sync_handler+0xa4/0x130 |
| el0t_64_sync+0x18c/0x190 |
| Code: 14000016 f94000a5 eb05029f 54000260 (b94018a6) |
| ---[ end trace 0000000000000000 ]--- |
| |
| The Linux kernel CVE team has assigned CVE-2022-49393 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.18 with commit 5c1b97c7d7b736e6439af4f43a65837bc72f56c1 and fixed in 5.18.3 with commit 2d12905aad462383f4e7a5fdb024d2b7ae2d10cf |
| Issue introduced in 5.18 with commit 5c1b97c7d7b736e6439af4f43a65837bc72f56c1 and fixed in 5.19 with commit c5c07c5958cf0c9af6e76813e6de15d42ee49822 |
| |
| 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-2022-49393 |
| 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/misc/fastrpc.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/2d12905aad462383f4e7a5fdb024d2b7ae2d10cf |
| https://git.kernel.org/stable/c/c5c07c5958cf0c9af6e76813e6de15d42ee49822 |
