From bippy-d175d3acf727 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman To: Reply-to: , Subject: CVE-2021-47374: dma-debug: prevent an error message from causing runtime problems Description =========== In the Linux kernel, the following vulnerability has been resolved: dma-debug: prevent an error message from causing runtime problems For some drivers, that use the DMA API. This error message can be reached several millions of times per second, causing spam to the kernel's printk buffer and bringing the CPU usage up to 100% (so, it should be rate limited). However, since there is at least one driver that is in the mainline and suffers from the error condition, it is more useful to err_printk() here instead of just rate limiting the error message (in hopes that it will make it easier for other drivers that suffer from this issue to be spotted). The Linux kernel CVE team has assigned CVE-2021-47374 to this issue. Affected and fixed versions =========================== Fixed in 5.14.9 with commit de4afec2d294 Fixed in 5.15 with commit 510e1a724ab1 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-2021-47374 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/debug.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/de4afec2d2946c92c62a15ab341c70b287289e6a https://git.kernel.org/stable/c/510e1a724ab1bf38150be2c1acabb303f98d0047