| 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-2024-50278: dm cache: fix potential out-of-bounds access on the first resume |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| dm cache: fix potential out-of-bounds access on the first resume |
| |
| Out-of-bounds access occurs if the fast device is expanded unexpectedly |
| before the first-time resume of the cache table. This happens because |
| expanding the fast device requires reloading the cache table for |
| cache_create to allocate new in-core data structures that fit the new |
| size, and the check in cache_preresume is not performed during the |
| first resume, leading to the issue. |
| |
| Reproduce steps: |
| |
| 1. prepare component devices: |
| |
| dmsetup create cmeta --table "0 8192 linear /dev/sdc 0" |
| dmsetup create cdata --table "0 65536 linear /dev/sdc 8192" |
| dmsetup create corig --table "0 524288 linear /dev/sdc 262144" |
| dd if=/dev/zero of=/dev/mapper/cmeta bs=4k count=1 oflag=direct |
| |
| 2. load a cache table of 512 cache blocks, and deliberately expand the |
| fast device before resuming the cache, making the in-core data |
| structures inadequate. |
| |
| dmsetup create cache --notable |
| dmsetup reload cache --table "0 524288 cache /dev/mapper/cmeta \ |
| /dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0" |
| dmsetup reload cdata --table "0 131072 linear /dev/sdc 8192" |
| dmsetup resume cdata |
| dmsetup resume cache |
| |
| 3. suspend the cache to write out the in-core dirty bitset and hint |
| array, leading to out-of-bounds access to the dirty bitset at offset |
| 0x40: |
| |
| dmsetup suspend cache |
| |
| KASAN reports: |
| |
| BUG: KASAN: vmalloc-out-of-bounds in is_dirty_callback+0x2b/0x80 |
| Read of size 8 at addr ffffc90000085040 by task dmsetup/90 |
| |
| (...snip...) |
| The buggy address belongs to the virtual mapping at |
| [ffffc90000085000, ffffc90000087000) created by: |
| cache_ctr+0x176a/0x35f0 |
| |
| (...snip...) |
| Memory state around the buggy address: |
| ffffc90000084f00: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 |
| ffffc90000084f80: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 |
| >ffffc90000085000: 00 00 00 00 00 00 00 00 f8 f8 f8 f8 f8 f8 f8 f8 |
| ^ |
| ffffc90000085080: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 |
| ffffc90000085100: f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 f8 |
| |
| Fix by checking the size change on the first resume. |
| |
| The Linux kernel CVE team has assigned CVE-2024-50278 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 3.13 with commit f494a9c6b1b6dd9a9f21bbb75d9210d478eeb498 and fixed in 4.19.324 with commit e492f71854ce03474d49e87fd98b8df1f7cd1d2d |
| Issue introduced in 3.13 with commit f494a9c6b1b6dd9a9f21bbb75d9210d478eeb498 and fixed in 5.4.286 with commit 2222b0929d00e2d13732b799b63be391b5de4492 |
| Issue introduced in 3.13 with commit f494a9c6b1b6dd9a9f21bbb75d9210d478eeb498 and fixed in 5.10.230 with commit 483b7261b35a9d369082ab298a6670912243f0be |
| Issue introduced in 3.13 with commit f494a9c6b1b6dd9a9f21bbb75d9210d478eeb498 and fixed in 5.15.172 with commit fdef3b94dfebd57e3077a578b6e309a2bb6fa688 |
| Issue introduced in 3.13 with commit f494a9c6b1b6dd9a9f21bbb75d9210d478eeb498 and fixed in 6.1.117 with commit c52ec00cb2f9bebfada22edcc0db385b910a1cdb |
| Issue introduced in 3.13 with commit f494a9c6b1b6dd9a9f21bbb75d9210d478eeb498 and fixed in 6.6.61 with commit 036dd6e3d2638103e0092864577ea1d091466b86 |
| Issue introduced in 3.13 with commit f494a9c6b1b6dd9a9f21bbb75d9210d478eeb498 and fixed in 6.11.8 with commit 13ed3624c6ef283acefa4cc42cc8ae54fd4391a4 |
| Issue introduced in 3.13 with commit f494a9c6b1b6dd9a9f21bbb75d9210d478eeb498 and fixed in 6.12 with commit c0ade5d98979585d4f5a93e4514c2e9a65afa08d |
| |
| 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-2024-50278 |
| 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/md/dm-cache-target.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/e492f71854ce03474d49e87fd98b8df1f7cd1d2d |
| https://git.kernel.org/stable/c/2222b0929d00e2d13732b799b63be391b5de4492 |
| https://git.kernel.org/stable/c/483b7261b35a9d369082ab298a6670912243f0be |
| https://git.kernel.org/stable/c/fdef3b94dfebd57e3077a578b6e309a2bb6fa688 |
| https://git.kernel.org/stable/c/c52ec00cb2f9bebfada22edcc0db385b910a1cdb |
| https://git.kernel.org/stable/c/036dd6e3d2638103e0092864577ea1d091466b86 |
| https://git.kernel.org/stable/c/13ed3624c6ef283acefa4cc42cc8ae54fd4391a4 |
| https://git.kernel.org/stable/c/c0ade5d98979585d4f5a93e4514c2e9a65afa08d |
