| 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-2021-47012: RDMA/siw: Fix a use after free in siw_alloc_mr |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| RDMA/siw: Fix a use after free in siw_alloc_mr |
| |
| Our code analyzer reported a UAF. |
| |
| In siw_alloc_mr(), it calls siw_mr_add_mem(mr,..). In the implementation of |
| siw_mr_add_mem(), mem is assigned to mr->mem and then mem is freed via |
| kfree(mem) if xa_alloc_cyclic() failed. Here, mr->mem still point to a |
| freed object. After, the execution continue up to the err_out branch of |
| siw_alloc_mr, and the freed mr->mem is used in siw_mr_drop_mem(mr). |
| |
| My patch moves "mr->mem = mem" behind the if (xa_alloc_cyclic(..)<0) {} |
| section, to avoid the uaf. |
| |
| The Linux kernel CVE team has assigned CVE-2021-47012 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.3 with commit 2251334dcac9eb337575d8767e2a6a7e81848f7f and fixed in 5.4.119 with commit 30b9e92d0b5e5d5dc1101ab856c17009537cbca4 |
| Issue introduced in 5.3 with commit 2251334dcac9eb337575d8767e2a6a7e81848f7f and fixed in 5.10.37 with commit 608a4b90ece039940e9425ee2b39c8beff27e00c |
| Issue introduced in 5.3 with commit 2251334dcac9eb337575d8767e2a6a7e81848f7f and fixed in 5.11.21 with commit 3e22b88e02c194f6c80867abfef5cc09383461f4 |
| Issue introduced in 5.3 with commit 2251334dcac9eb337575d8767e2a6a7e81848f7f and fixed in 5.12.4 with commit ad9ce7188432650469a6c7625bf479f5ed0b6155 |
| Issue introduced in 5.3 with commit 2251334dcac9eb337575d8767e2a6a7e81848f7f and fixed in 5.13 with commit 3093ee182f01689b89e9f8797b321603e5de4f63 |
| |
| 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-2021-47012 |
| 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/infiniband/sw/siw/siw_mem.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/30b9e92d0b5e5d5dc1101ab856c17009537cbca4 |
| https://git.kernel.org/stable/c/608a4b90ece039940e9425ee2b39c8beff27e00c |
| https://git.kernel.org/stable/c/3e22b88e02c194f6c80867abfef5cc09383461f4 |
| https://git.kernel.org/stable/c/ad9ce7188432650469a6c7625bf479f5ed0b6155 |
| https://git.kernel.org/stable/c/3093ee182f01689b89e9f8797b321603e5de4f63 |
