| 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-2021-47066: async_xor: increase src_offs when dropping destination page |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| async_xor: increase src_offs when dropping destination page |
| |
| Now we support sharing one page if PAGE_SIZE is not equal stripe size. To |
| support this, it needs to support calculating xor value with different |
| offsets for each r5dev. One offset array is used to record those offsets. |
| |
| In RMW mode, parity page is used as a source page. It sets |
| ASYNC_TX_XOR_DROP_DST before calculating xor value in ops_run_prexor5. |
| So it needs to add src_list and src_offs at the same time. Now it only |
| needs src_list. So the xor value which is calculated is wrong. It can |
| cause data corruption problem. |
| |
| I can reproduce this problem 100% on a POWER8 machine. The steps are: |
| |
| mdadm -CR /dev/md0 -l5 -n3 /dev/sdb1 /dev/sdc1 /dev/sdd1 --size=3G |
| mkfs.xfs /dev/md0 |
| mount /dev/md0 /mnt/test |
| mount: /mnt/test: mount(2) system call failed: Structure needs cleaning. |
| |
| The Linux kernel CVE team has assigned CVE-2021-47066 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.10 with commit 29bcff787a2593b2126cfaff612c0b4e560022e9 and fixed in 5.10.37 with commit cab2e8e5997b592fdb7d02cf2387b4b8e3057174 |
| Issue introduced in 5.10 with commit 29bcff787a2593b2126cfaff612c0b4e560022e9 and fixed in 5.11.21 with commit 29ffa50f33de824b5491f8239c88c4a0efdd03af |
| Issue introduced in 5.10 with commit 29bcff787a2593b2126cfaff612c0b4e560022e9 and fixed in 5.12.4 with commit 53f8208e11abd6dde9480dfcb97fecdb1bc2ac18 |
| Issue introduced in 5.10 with commit 29bcff787a2593b2126cfaff612c0b4e560022e9 and fixed in 5.13 with commit ceaf2966ab082bbc4d26516f97b3ca8a676e2af8 |
| |
| 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-2021-47066 |
| 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: |
| crypto/async_tx/async_xor.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/cab2e8e5997b592fdb7d02cf2387b4b8e3057174 |
| https://git.kernel.org/stable/c/29ffa50f33de824b5491f8239c88c4a0efdd03af |
| https://git.kernel.org/stable/c/53f8208e11abd6dde9480dfcb97fecdb1bc2ac18 |
| https://git.kernel.org/stable/c/ceaf2966ab082bbc4d26516f97b3ca8a676e2af8 |
