| 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-2022-49708: ext4: fix bug_on ext4_mb_use_inode_pa |
| |
| Description |
| =========== |
| |
| In the Linux kernel, the following vulnerability has been resolved: |
| |
| ext4: fix bug_on ext4_mb_use_inode_pa |
| |
| Hulk Robot reported a BUG_ON: |
| ================================================================== |
| kernel BUG at fs/ext4/mballoc.c:3211! |
| [...] |
| RIP: 0010:ext4_mb_mark_diskspace_used.cold+0x85/0x136f |
| [...] |
| Call Trace: |
| ext4_mb_new_blocks+0x9df/0x5d30 |
| ext4_ext_map_blocks+0x1803/0x4d80 |
| ext4_map_blocks+0x3a4/0x1a10 |
| ext4_writepages+0x126d/0x2c30 |
| do_writepages+0x7f/0x1b0 |
| __filemap_fdatawrite_range+0x285/0x3b0 |
| file_write_and_wait_range+0xb1/0x140 |
| ext4_sync_file+0x1aa/0xca0 |
| vfs_fsync_range+0xfb/0x260 |
| do_fsync+0x48/0xa0 |
| [...] |
| ================================================================== |
| |
| Above issue may happen as follows: |
| ------------------------------------- |
| do_fsync |
| vfs_fsync_range |
| ext4_sync_file |
| file_write_and_wait_range |
| __filemap_fdatawrite_range |
| do_writepages |
| ext4_writepages |
| mpage_map_and_submit_extent |
| mpage_map_one_extent |
| ext4_map_blocks |
| ext4_mb_new_blocks |
| ext4_mb_normalize_request |
| >>> start + size <= ac->ac_o_ex.fe_logical |
| ext4_mb_regular_allocator |
| ext4_mb_simple_scan_group |
| ext4_mb_use_best_found |
| ext4_mb_new_preallocation |
| ext4_mb_new_inode_pa |
| ext4_mb_use_inode_pa |
| >>> set ac->ac_b_ex.fe_len <= 0 |
| ext4_mb_mark_diskspace_used |
| >>> BUG_ON(ac->ac_b_ex.fe_len <= 0); |
| |
| we can easily reproduce this problem with the following commands: |
| `fallocate -l100M disk` |
| `mkfs.ext4 -b 1024 -g 256 disk` |
| `mount disk /mnt` |
| `fsstress -d /mnt -l 0 -n 1000 -p 1` |
| |
| The size must be smaller than or equal to EXT4_BLOCKS_PER_GROUP. |
| Therefore, "start + size <= ac->ac_o_ex.fe_logical" may occur |
| when the size is truncated. So start should be the start position of |
| the group where ac_o_ex.fe_logical is located after alignment. |
| In addition, when the value of fe_logical or EXT4_BLOCKS_PER_GROUP |
| is very large, the value calculated by start_off is more accurate. |
| |
| The Linux kernel CVE team has assigned CVE-2022-49708 to this issue. |
| |
| |
| Affected and fixed versions |
| =========================== |
| |
| Issue introduced in 4.9.14 with commit fc6c2da174edd7a7b760b12c60d432d300e05cca and fixed in 4.9.320 with commit 6880fb2e64331b9fdc85d3f32b1d7e81ad8703f1 |
| Issue introduced in 4.11 with commit cd648b8a8fd5071d232242d5ee7ee3c0815776af and fixed in 4.14.285 with commit a37c1359714da42517dd19d36fc3c4d17edba832 |
| Issue introduced in 4.11 with commit cd648b8a8fd5071d232242d5ee7ee3c0815776af and fixed in 4.19.249 with commit 5707d721d1819db57dba57b1d4623034fcb32047 |
| Issue introduced in 4.11 with commit cd648b8a8fd5071d232242d5ee7ee3c0815776af and fixed in 5.4.200 with commit a6b31616e5afe1d3972cb0682a373e50597faf5c |
| Issue introduced in 4.11 with commit cd648b8a8fd5071d232242d5ee7ee3c0815776af and fixed in 5.10.124 with commit 6fdaf31ad5f3d3afab744dfd9a8b0d9142aa881f |
| Issue introduced in 4.11 with commit cd648b8a8fd5071d232242d5ee7ee3c0815776af and fixed in 5.15.49 with commit 90f0f9d45dff0128c0fca0d2358c4153b024afa6 |
| Issue introduced in 4.11 with commit cd648b8a8fd5071d232242d5ee7ee3c0815776af and fixed in 5.18.6 with commit 887a3e9ad4b8309a2266bce7ae749b2bf1f7a687 |
| Issue introduced in 4.11 with commit cd648b8a8fd5071d232242d5ee7ee3c0815776af and fixed in 5.19 with commit a08f789d2ab5242c07e716baf9a835725046be89 |
| Issue introduced in 3.2.89 with commit f213db429b883a2d5403de0b1ce92fb7d7ee979e |
| Issue introduced in 3.10.107 with commit 98f58e05231f835dfb09359e3b5e3a886fe8f189 |
| Issue introduced in 3.12.72 with commit c1664e9bcf6291c0ceb8599f57c8cf493526abe6 |
| Issue introduced in 3.16.44 with commit 37cf4ab1ba60c30ca9fd0fe3b9993b24cb87886a |
| Issue introduced in 4.1.40 with commit 75f37dab088eb84ff25a49e59371f01ea3f44aa7 |
| Issue introduced in 4.4.53 with commit 8774c73cf6963310395823ed7077ea12943ea0f3 |
| Issue introduced in 4.10.2 with commit c4fbdc0124799f1772f4d886b7f2e1a6f881d195 |
| |
| 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-2022-49708 |
| 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/ext4/mballoc.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/6880fb2e64331b9fdc85d3f32b1d7e81ad8703f1 |
| https://git.kernel.org/stable/c/a37c1359714da42517dd19d36fc3c4d17edba832 |
| https://git.kernel.org/stable/c/5707d721d1819db57dba57b1d4623034fcb32047 |
| https://git.kernel.org/stable/c/a6b31616e5afe1d3972cb0682a373e50597faf5c |
| https://git.kernel.org/stable/c/6fdaf31ad5f3d3afab744dfd9a8b0d9142aa881f |
| https://git.kernel.org/stable/c/90f0f9d45dff0128c0fca0d2358c4153b024afa6 |
| https://git.kernel.org/stable/c/887a3e9ad4b8309a2266bce7ae749b2bf1f7a687 |
| https://git.kernel.org/stable/c/a08f789d2ab5242c07e716baf9a835725046be89 |
