| 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-2024-46744: Squashfs: sanity check symbolic link size |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| Squashfs: sanity check symbolic link size |
| |
| Syzkiller reports a "KMSAN: uninit-value in pick_link" bug. |
| |
| This is caused by an uninitialised page, which is ultimately caused |
| by a corrupted symbolic link size read from disk. |
| |
| The reason why the corrupted symlink size causes an uninitialised |
| page is due to the following sequence of events: |
| |
| 1. squashfs_read_inode() is called to read the symbolic |
| link from disk. This assigns the corrupted value |
| 3875536935 to inode->i_size. |
| |
| 2. Later squashfs_symlink_read_folio() is called, which assigns |
| this corrupted value to the length variable, which being a |
| signed int, overflows producing a negative number. |
| |
| 3. The following loop that fills in the page contents checks that |
| the copied bytes is less than length, which being negative means |
| the loop is skipped, producing an uninitialised page. |
| |
| This patch adds a sanity check which checks that the symbolic |
| link size is not larger than expected. |
| |
| -- |
| |
| V2: fix spelling mistake. |
| |
| The Linux kernel CVE team has assigned CVE-2024-46744 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Fixed in 4.19.322 with commit f82cb7f24032ed023fc67d26ea9bf322d8431a90 |
| Fixed in 5.4.284 with commit 1b9451ba6f21478a75288ea3e3fca4be35e2a438 |
| Fixed in 5.10.226 with commit 5c8906de98d0d7ad42ff3edf2cb6cd7e0ea658c4 |
| Fixed in 5.15.167 with commit 087f25b2d36adae19951114ffcbb7106ed405ebb |
| Fixed in 6.1.110 with commit fac5e82ab1334fc8ed6ff7183702df634bd1d93d |
| Fixed in 6.6.51 with commit c3af7e460a526007e4bed1ce3623274a1a6afe5e |
| Fixed in 6.10.10 with commit ef4e249971eb77ec33d74c5c3de1e2576faf6c90 |
| Fixed in 6.11 with commit 810ee43d9cd245d138a2733d87a24858a23f577d |
| |
| 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-2024-46744 |
| 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: |
| fs/squashfs/inode.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/f82cb7f24032ed023fc67d26ea9bf322d8431a90 |
| https://git.kernel.org/stable/c/1b9451ba6f21478a75288ea3e3fca4be35e2a438 |
| https://git.kernel.org/stable/c/5c8906de98d0d7ad42ff3edf2cb6cd7e0ea658c4 |
| https://git.kernel.org/stable/c/087f25b2d36adae19951114ffcbb7106ed405ebb |
| https://git.kernel.org/stable/c/fac5e82ab1334fc8ed6ff7183702df634bd1d93d |
| https://git.kernel.org/stable/c/c3af7e460a526007e4bed1ce3623274a1a6afe5e |
| https://git.kernel.org/stable/c/ef4e249971eb77ec33d74c5c3de1e2576faf6c90 |
| https://git.kernel.org/stable/c/810ee43d9cd245d138a2733d87a24858a23f577d |
