| 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-2021-47554: vdpa_sim: avoid putting an uninitialized iova_domain |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| vdpa_sim: avoid putting an uninitialized iova_domain |
| |
| The system will crash if we put an uninitialized iova_domain, this |
| could happen when an error occurs before initializing the iova_domain |
| in vdpasim_create(). |
| |
| BUG: kernel NULL pointer dereference, address: 0000000000000000 |
| ... |
| RIP: 0010:__cpuhp_state_remove_instance+0x96/0x1c0 |
| ... |
| Call Trace: |
| <TASK> |
| put_iova_domain+0x29/0x220 |
| vdpasim_free+0xd1/0x120 [vdpa_sim] |
| vdpa_release_dev+0x21/0x40 [vdpa] |
| device_release+0x33/0x90 |
| kobject_release+0x63/0x160 |
| vdpasim_create+0x127/0x2a0 [vdpa_sim] |
| vdpasim_net_dev_add+0x7d/0xfe [vdpa_sim_net] |
| vdpa_nl_cmd_dev_add_set_doit+0xe1/0x1a0 [vdpa] |
| genl_family_rcv_msg_doit+0x112/0x140 |
| genl_rcv_msg+0xdf/0x1d0 |
| ... |
| |
| So we must make sure the iova_domain is already initialized before |
| put it. |
| |
| In addition, we may get the following warning in this case: |
| WARNING: ... drivers/iommu/iova.c:344 iova_cache_put+0x58/0x70 |
| |
| So we must make sure the iova_cache_put() is invoked only if the |
| iova_cache_get() is already invoked. Let's fix it together. |
| |
| The Linux kernel CVE team has assigned CVE-2021-47554 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.13 with commit 4080fc1067501707b9693b8003feae7d50d14e35 and fixed in 5.15.6 with commit e4d58ac67e63727aa45a4a26185876f598e8b3dd |
| Issue introduced in 5.13 with commit 4080fc1067501707b9693b8003feae7d50d14e35 and fixed in 5.16 with commit bb93ce4b150dde79f58e34103cbd1fe829796649 |
| |
| 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-2021-47554 |
| 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/vdpa/vdpa_sim/vdpa_sim.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/e4d58ac67e63727aa45a4a26185876f598e8b3dd |
| https://git.kernel.org/stable/c/bb93ce4b150dde79f58e34103cbd1fe829796649 |
