| 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-2024-26696: nilfs2: fix hang in nilfs_lookup_dirty_data_buffers() |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| nilfs2: fix hang in nilfs_lookup_dirty_data_buffers() |
| |
| Syzbot reported a hang issue in migrate_pages_batch() called by mbind() |
| and nilfs_lookup_dirty_data_buffers() called in the log writer of nilfs2. |
| |
| While migrate_pages_batch() locks a folio and waits for the writeback to |
| complete, the log writer thread that should bring the writeback to |
| completion picks up the folio being written back in |
| nilfs_lookup_dirty_data_buffers() that it calls for subsequent log |
| creation and was trying to lock the folio. Thus causing a deadlock. |
| |
| In the first place, it is unexpected that folios/pages in the middle of |
| writeback will be updated and become dirty. Nilfs2 adds a checksum to |
| verify the validity of the log being written and uses it for recovery at |
| mount, so data changes during writeback are suppressed. Since this is |
| broken, an unclean shutdown could potentially cause recovery to fail. |
| |
| Investigation revealed that the root cause is that the wait for writeback |
| completion in nilfs_page_mkwrite() is conditional, and if the backing |
| device does not require stable writes, data may be modified without |
| waiting. |
| |
| Fix these issues by making nilfs_page_mkwrite() wait for writeback to |
| finish regardless of the stable write requirement of the backing device. |
| |
| The Linux kernel CVE team has assigned CVE-2024-26696 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 3.9 with commit 1d1d1a767206fbe5d4c69493b7e6d2a8d08cc0a0 and fixed in 4.19.307 with commit 228742b2ddfb99dfd71e5a307e6088ab6836272e |
| Issue introduced in 3.9 with commit 1d1d1a767206fbe5d4c69493b7e6d2a8d08cc0a0 and fixed in 5.4.269 with commit 862ee4422c38be5c249844a684b00d0dbe9d1e46 |
| Issue introduced in 3.9 with commit 1d1d1a767206fbe5d4c69493b7e6d2a8d08cc0a0 and fixed in 5.10.210 with commit 98a4026b22ff440c7f47056481bcbbe442f607d6 |
| Issue introduced in 3.9 with commit 1d1d1a767206fbe5d4c69493b7e6d2a8d08cc0a0 and fixed in 5.15.149 with commit 7e9b622bd0748cc104d66535b76d9b3535f9dc0f |
| Issue introduced in 3.9 with commit 1d1d1a767206fbe5d4c69493b7e6d2a8d08cc0a0 and fixed in 6.1.79 with commit 8494ba2c9ea00a54d5b50e69b22c55a8958bce32 |
| Issue introduced in 3.9 with commit 1d1d1a767206fbe5d4c69493b7e6d2a8d08cc0a0 and fixed in 6.6.18 with commit ea5ddbc11613b55e5128c85f57b08f907abd9b28 |
| Issue introduced in 3.9 with commit 1d1d1a767206fbe5d4c69493b7e6d2a8d08cc0a0 and fixed in 6.7.6 with commit e38585401d464578d30f5868ff4ca54475c34f7d |
| Issue introduced in 3.9 with commit 1d1d1a767206fbe5d4c69493b7e6d2a8d08cc0a0 and fixed in 6.8 with commit 38296afe3c6ee07319e01bb249aa4bb47c07b534 |
| |
| 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-2024-26696 |
| 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/nilfs2/file.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/228742b2ddfb99dfd71e5a307e6088ab6836272e |
| https://git.kernel.org/stable/c/862ee4422c38be5c249844a684b00d0dbe9d1e46 |
| https://git.kernel.org/stable/c/98a4026b22ff440c7f47056481bcbbe442f607d6 |
| https://git.kernel.org/stable/c/7e9b622bd0748cc104d66535b76d9b3535f9dc0f |
| https://git.kernel.org/stable/c/8494ba2c9ea00a54d5b50e69b22c55a8958bce32 |
| https://git.kernel.org/stable/c/ea5ddbc11613b55e5128c85f57b08f907abd9b28 |
| https://git.kernel.org/stable/c/e38585401d464578d30f5868ff4ca54475c34f7d |
| https://git.kernel.org/stable/c/38296afe3c6ee07319e01bb249aa4bb47c07b534 |
