| 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-2024-26956: nilfs2: fix failure to detect DAT corruption in btree and direct mappings |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| nilfs2: fix failure to detect DAT corruption in btree and direct mappings |
| |
| Patch series "nilfs2: fix kernel bug at submit_bh_wbc()". |
| |
| This resolves a kernel BUG reported by syzbot. Since there are two |
| flaws involved, I've made each one a separate patch. |
| |
| The first patch alone resolves the syzbot-reported bug, but I think |
| both fixes should be sent to stable, so I've tagged them as such. |
| |
| |
| This patch (of 2): |
| |
| Syzbot has reported a kernel bug in submit_bh_wbc() when writing file data |
| to a nilfs2 file system whose metadata is corrupted. |
| |
| There are two flaws involved in this issue. |
| |
| The first flaw is that when nilfs_get_block() locates a data block using |
| btree or direct mapping, if the disk address translation routine |
| nilfs_dat_translate() fails with internal code -ENOENT due to DAT metadata |
| corruption, it can be passed back to nilfs_get_block(). This causes |
| nilfs_get_block() to misidentify an existing block as non-existent, |
| causing both data block lookup and insertion to fail inconsistently. |
| |
| The second flaw is that nilfs_get_block() returns a successful status in |
| this inconsistent state. This causes the caller __block_write_begin_int() |
| or others to request a read even though the buffer is not mapped, |
| resulting in a BUG_ON check for the BH_Mapped flag in submit_bh_wbc() |
| failing. |
| |
| This fixes the first issue by changing the return value to code -EINVAL |
| when a conversion using DAT fails with code -ENOENT, avoiding the |
| conflicting condition that leads to the kernel bug described above. Here, |
| code -EINVAL indicates that metadata corruption was detected during the |
| block lookup, which will be properly handled as a file system error and |
| converted to -EIO when passing through the nilfs2 bmap layer. |
| |
| The Linux kernel CVE team has assigned CVE-2024-26956 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 2.6.31 with commit c3a7abf06ce719a51139e62a034590be99abbc2c and fixed in 4.19.312 with commit b67189690eb4b7ecc84ae16fa1e880e0123eaa35 |
| Issue introduced in 2.6.31 with commit c3a7abf06ce719a51139e62a034590be99abbc2c and fixed in 5.4.274 with commit 9cbe1ad5f4354f4df1445e5f4883983328cd6d8e |
| Issue introduced in 2.6.31 with commit c3a7abf06ce719a51139e62a034590be99abbc2c and fixed in 5.10.215 with commit c3b5c5c31e723b568f83d8cafab8629d9d830ffb |
| Issue introduced in 2.6.31 with commit c3a7abf06ce719a51139e62a034590be99abbc2c and fixed in 5.15.154 with commit 2e2619ff5d0def4bb6c2037a32a6eaa28dd95c84 |
| Issue introduced in 2.6.31 with commit c3a7abf06ce719a51139e62a034590be99abbc2c and fixed in 6.1.84 with commit 46b832e09d43b394ac0f6d9485d2b1a06593f0b7 |
| Issue introduced in 2.6.31 with commit c3a7abf06ce719a51139e62a034590be99abbc2c and fixed in 6.6.24 with commit f69e81396aea66304d214f175aa371f1b5578862 |
| Issue introduced in 2.6.31 with commit c3a7abf06ce719a51139e62a034590be99abbc2c and fixed in 6.7.12 with commit a8e4d098de1c0f4c5c1f2ed4633a860f0da6d713 |
| Issue introduced in 2.6.31 with commit c3a7abf06ce719a51139e62a034590be99abbc2c and fixed in 6.8.3 with commit 82827ca21e7c8a91384c5baa656f78a5adfa4ab4 |
| Issue introduced in 2.6.31 with commit c3a7abf06ce719a51139e62a034590be99abbc2c and fixed in 6.9 with commit f2f26b4a84a0ef41791bd2d70861c8eac748f4ba |
| |
| 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-2024-26956 |
| 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/btree.c |
| fs/nilfs2/direct.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/b67189690eb4b7ecc84ae16fa1e880e0123eaa35 |
| https://git.kernel.org/stable/c/9cbe1ad5f4354f4df1445e5f4883983328cd6d8e |
| https://git.kernel.org/stable/c/c3b5c5c31e723b568f83d8cafab8629d9d830ffb |
| https://git.kernel.org/stable/c/2e2619ff5d0def4bb6c2037a32a6eaa28dd95c84 |
| https://git.kernel.org/stable/c/46b832e09d43b394ac0f6d9485d2b1a06593f0b7 |
| https://git.kernel.org/stable/c/f69e81396aea66304d214f175aa371f1b5578862 |
| https://git.kernel.org/stable/c/a8e4d098de1c0f4c5c1f2ed4633a860f0da6d713 |
| https://git.kernel.org/stable/c/82827ca21e7c8a91384c5baa656f78a5adfa4ab4 |
| https://git.kernel.org/stable/c/f2f26b4a84a0ef41791bd2d70861c8eac748f4ba |
