| 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-2025-21874: dm-integrity: Avoid divide by zero in table status in Inline mode |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| dm-integrity: Avoid divide by zero in table status in Inline mode |
| |
| In Inline mode, the journal is unused, and journal_sectors is zero. |
| |
| Calculating the journal watermark requires dividing by journal_sectors, |
| which should be done only if the journal is configured. |
| |
| Otherwise, a simple table query (dmsetup table) can cause OOPS. |
| |
| This bug did not show on some systems, perhaps only due to |
| compiler optimization. |
| |
| On my 32-bit testing machine, this reliably crashes with the following: |
| |
| : Oops: divide error: 0000 [#1] PREEMPT SMP |
| : CPU: 0 UID: 0 PID: 2450 Comm: dmsetup Not tainted 6.14.0-rc2+ #959 |
| : EIP: dm_integrity_status+0x2f8/0xab0 [dm_integrity] |
| ... |
| |
| The Linux kernel CVE team has assigned CVE-2025-21874 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 6.11 with commit fb0987682c629c1d2c476f35f6fde405a5e304a4 and fixed in 6.12.18 with commit 22c6f577b3cb184857b440ae5e5916f6c9e7021d |
| Issue introduced in 6.11 with commit fb0987682c629c1d2c476f35f6fde405a5e304a4 and fixed in 6.13.6 with commit 06d9895f265282e939a8933bb18de82eba2b4dda |
| Issue introduced in 6.11 with commit fb0987682c629c1d2c476f35f6fde405a5e304a4 and fixed in 6.14 with commit 7fb39882b20c98a9a393c244c86b56ef6933cff8 |
| |
| 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-2025-21874 |
| 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/dm-integrity.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/22c6f577b3cb184857b440ae5e5916f6c9e7021d |
| https://git.kernel.org/stable/c/06d9895f265282e939a8933bb18de82eba2b4dda |
| https://git.kernel.org/stable/c/7fb39882b20c98a9a393c244c86b56ef6933cff8 |
