| 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-2024-39482: bcache: fix variable length array abuse in btree_iter |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| bcache: fix variable length array abuse in btree_iter |
| |
| btree_iter is used in two ways: either allocated on the stack with a |
| fixed size MAX_BSETS, or from a mempool with a dynamic size based on the |
| specific cache set. Previously, the struct had a fixed-length array of |
| size MAX_BSETS which was indexed out-of-bounds for the dynamically-sized |
| iterators, which causes UBSAN to complain. |
| |
| This patch uses the same approach as in bcachefs's sort_iter and splits |
| the iterator into a btree_iter with a flexible array member and a |
| btree_iter_stack which embeds a btree_iter as well as a fixed-length |
| data array. |
| |
| The Linux kernel CVE team has assigned CVE-2024-39482 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 5.10.221 with commit 2c3d7b03b658dc8bfa6112b194b67b92a87e081b |
| Fixed in 5.15.162 with commit 5a1922adc5798b7ec894cd3f197afb6f9591b023 |
| Fixed in 6.1.94 with commit 934e1e4331859183a861f396d7dfaf33cb5afb02 |
| Fixed in 6.6.34 with commit 6479b9f41583b013041943c4602e1ad61cec8148 |
| Fixed in 6.9.5 with commit 0c31344e22dd8d6b1394c6e4c41d639015bdc671 |
| Fixed in 6.10 with commit 3a861560ccb35f2a4f0a4b8207fa7c2a35fc7f31 |
| |
| 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-2024-39482 |
| 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/bcache/bset.c |
| drivers/md/bcache/bset.h |
| drivers/md/bcache/btree.c |
| drivers/md/bcache/super.c |
| drivers/md/bcache/sysfs.c |
| drivers/md/bcache/writeback.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/2c3d7b03b658dc8bfa6112b194b67b92a87e081b |
| https://git.kernel.org/stable/c/5a1922adc5798b7ec894cd3f197afb6f9591b023 |
| https://git.kernel.org/stable/c/934e1e4331859183a861f396d7dfaf33cb5afb02 |
| https://git.kernel.org/stable/c/6479b9f41583b013041943c4602e1ad61cec8148 |
| https://git.kernel.org/stable/c/0c31344e22dd8d6b1394c6e4c41d639015bdc671 |
| https://git.kernel.org/stable/c/3a861560ccb35f2a4f0a4b8207fa7c2a35fc7f31 |
