| 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-2024-36925: swiotlb: initialise restricted pool list_head when SWIOTLB_DYNAMIC=y |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| swiotlb: initialise restricted pool list_head when SWIOTLB_DYNAMIC=y |
| |
| Using restricted DMA pools (CONFIG_DMA_RESTRICTED_POOL=y) in conjunction |
| with dynamic SWIOTLB (CONFIG_SWIOTLB_DYNAMIC=y) leads to the following |
| crash when initialising the restricted pools at boot-time: |
| |
| | Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 |
| | Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP |
| | pc : rmem_swiotlb_device_init+0xfc/0x1ec |
| | lr : rmem_swiotlb_device_init+0xf0/0x1ec |
| | Call trace: |
| | rmem_swiotlb_device_init+0xfc/0x1ec |
| | of_reserved_mem_device_init_by_idx+0x18c/0x238 |
| | of_dma_configure_id+0x31c/0x33c |
| | platform_dma_configure+0x34/0x80 |
| |
| faddr2line reveals that the crash is in the list validation code: |
| |
| include/linux/list.h:83 |
| include/linux/rculist.h:79 |
| include/linux/rculist.h:106 |
| kernel/dma/swiotlb.c:306 |
| kernel/dma/swiotlb.c:1695 |
| |
| because add_mem_pool() is trying to list_add_rcu() to a NULL |
| 'mem->pools'. |
| |
| Fix the crash by initialising the 'mem->pools' list_head in |
| rmem_swiotlb_device_init() before calling add_mem_pool(). |
| |
| The Linux kernel CVE team has assigned CVE-2024-36925 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.6 with commit 1aaa736815eb04f4dae3f0b3e977b2a0677a4cfb and fixed in 6.6.31 with commit f2a6b3ed20f2dea4cb645abc6a73c4595662adca |
| Issue introduced in 6.6 with commit 1aaa736815eb04f4dae3f0b3e977b2a0677a4cfb and fixed in 6.8.10 with commit f62e0fefcdfe2c05ccb1aa80521a69524eea9c84 |
| Issue introduced in 6.6 with commit 1aaa736815eb04f4dae3f0b3e977b2a0677a4cfb and fixed in 6.9 with commit 75961ffb5cb3e5196f19cae7683f35cc88b50800 |
| |
| 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-2024-36925 |
| 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: |
| kernel/dma/swiotlb.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/f2a6b3ed20f2dea4cb645abc6a73c4595662adca |
| https://git.kernel.org/stable/c/f62e0fefcdfe2c05ccb1aa80521a69524eea9c84 |
| https://git.kernel.org/stable/c/75961ffb5cb3e5196f19cae7683f35cc88b50800 |
