| From bippy-1.1.0 Mon Sep 17 00:00:00 2001 |
| From: Greg Kroah-Hartman <gregkh@kernel.org> |
| To: <linux-cve-announce@vger.kernel.org> |
| Reply-to: <cve@kernel.org>, <linux-kernel@vger.kernel.org> |
| Subject: CVE-2022-49913: btrfs: fix inode list leak during backref walking at find_parent_nodes() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| btrfs: fix inode list leak during backref walking at find_parent_nodes() |
| |
| During backref walking, at find_parent_nodes(), if we are dealing with a |
| data extent and we get an error while resolving the indirect backrefs, at |
| resolve_indirect_refs(), or in the while loop that iterates over the refs |
| in the direct refs rbtree, we end up leaking the inode lists attached to |
| the direct refs we have in the direct refs rbtree that were not yet added |
| to the refs ulist passed as argument to find_parent_nodes(). Since they |
| were not yet added to the refs ulist and prelim_release() does not free |
| the lists, on error the caller can only free the lists attached to the |
| refs that were added to the refs ulist, all the remaining refs get their |
| inode lists never freed, therefore leaking their memory. |
| |
| Fix this by having prelim_release() always free any attached inode list |
| to each ref found in the rbtree, and have find_parent_nodes() set the |
| ref's inode list to NULL once it transfers ownership of the inode list |
| to a ref added to the refs ulist passed to find_parent_nodes(). |
| |
| The Linux kernel CVE team has assigned CVE-2022-49913 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.14 with commit 86d5f994425252d8a40e2184c94a2682ae8ecfbf and fixed in 5.4.224 with commit 6a6731a0df8c47ecc703bd7bb73459df767051e0 |
| Issue introduced in 4.14 with commit 86d5f994425252d8a40e2184c94a2682ae8ecfbf and fixed in 5.10.154 with commit 61e06128113711df0534c404fb6bb528eb7d2332 |
| Issue introduced in 4.14 with commit 86d5f994425252d8a40e2184c94a2682ae8ecfbf and fixed in 5.15.78 with commit 222a3d533027b9492d5b7f5ecdc01a90f57bb5a9 |
| Issue introduced in 4.14 with commit 86d5f994425252d8a40e2184c94a2682ae8ecfbf and fixed in 6.0.8 with commit 83ea8c5b54d452a5769e605e3c5c687e8ca06d89 |
| Issue introduced in 4.14 with commit 86d5f994425252d8a40e2184c94a2682ae8ecfbf and fixed in 6.1 with commit 92876eec382a0f19f33d09d2c939e9ca49038ae5 |
| |
| 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-2022-49913 |
| 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/btrfs/backref.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/6a6731a0df8c47ecc703bd7bb73459df767051e0 |
| https://git.kernel.org/stable/c/61e06128113711df0534c404fb6bb528eb7d2332 |
| https://git.kernel.org/stable/c/222a3d533027b9492d5b7f5ecdc01a90f57bb5a9 |
| https://git.kernel.org/stable/c/83ea8c5b54d452a5769e605e3c5c687e8ca06d89 |
| https://git.kernel.org/stable/c/92876eec382a0f19f33d09d2c939e9ca49038ae5 |
