| From bippy-1.2.0 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-2024-39496: btrfs: zoned: fix use-after-free due to race with dev replace |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| btrfs: zoned: fix use-after-free due to race with dev replace |
| |
| While loading a zone's info during creation of a block group, we can race |
| with a device replace operation and then trigger a use-after-free on the |
| device that was just replaced (source device of the replace operation). |
| |
| This happens because at btrfs_load_zone_info() we extract a device from |
| the chunk map into a local variable and then use the device while not |
| under the protection of the device replace rwsem. So if there's a device |
| replace operation happening when we extract the device and that device |
| is the source of the replace operation, we will trigger a use-after-free |
| if before we finish using the device the replace operation finishes and |
| frees the device. |
| |
| Fix this by enlarging the critical section under the protection of the |
| device replace rwsem so that all uses of the device are done inside the |
| critical section. |
| |
| The Linux kernel CVE team has assigned CVE-2024-39496 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 5.11 with commit 5b316468983dfa9473ff0f1c42e4e30b4c267141 and fixed in 6.1.95 with commit 17765964703b88d8befd899f8501150bb7e07e43 |
| Issue introduced in 5.11 with commit 5b316468983dfa9473ff0f1c42e4e30b4c267141 and fixed in 6.6.35 with commit 092571ef9a812566c8f2c9038d9c2a64c49788d6 |
| Issue introduced in 5.11 with commit 5b316468983dfa9473ff0f1c42e4e30b4c267141 and fixed in 6.9.6 with commit a0cc006f4214b87e70983c692e05bb36c59b5752 |
| Issue introduced in 5.11 with commit 5b316468983dfa9473ff0f1c42e4e30b4c267141 and fixed in 6.10 with commit 0090d6e1b210551e63cf43958dc7a1ec942cdde9 |
| |
| 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-2024-39496 |
| 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/zoned.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/17765964703b88d8befd899f8501150bb7e07e43 |
| https://git.kernel.org/stable/c/092571ef9a812566c8f2c9038d9c2a64c49788d6 |
| https://git.kernel.org/stable/c/a0cc006f4214b87e70983c692e05bb36c59b5752 |
| https://git.kernel.org/stable/c/0090d6e1b210551e63cf43958dc7a1ec942cdde9 |
