CVE-2021-47646
Description
In the Linux kernel, the following vulnerability has been resolved: Revert "Revert "block, bfq: honor already-setup queue merges"" A crash [1] happened to be triggered in conjunction with commit 2d52c58b9c9b ("block, bfq: honor already-setup queue merges"). The latter was then reverted by commit ebc69e897e17 ("Revert "block, bfq: honor already-setup queue merges""). Yet, the reverted commit was not the one introducing the bug. In fact, it actually triggered a UAF introduced by a different commit, and now fixed by commit d29bd41428cf ("block, bfq: reset last_bfqq_created on group change"). So, there is no point in keeping commit 2d52c58b9c9b ("block, bfq: honor already-setup queue merges") out. This commit restores it. [1] https://bugzilla.kernel.org/show_bug.cgi?id=214503
How to fix
- linux linux_kernel4.19.238, 5.4.189, 5.10.110, 5.15.33, 5.16.19, 5.17.2 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| linux linux_kernel | v < 4.19.238, 4.20 ≤ v < 5.4.189, 5.5 ≤ v < 5.10.110, 5.11 ≤ v < 5.15.33, 5.16 ≤ v < 5.16.19, 5.17 ≤ v < 5.17.2 | 4.19.238, 5.4.189, 5.10.110, 5.15.33, 5.16.19, 5.17.2 |
Check your version
Choose the product and enter the version you run to see whether it falls in the affected range.
Attack Surface Management
See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.