概要

ext4: fix bug_on ext4_mb_use_inode_pa

原文の説明

取得元が公開している説明をそのまま載せています (多くは英語)。

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…

出典: OSV.dev (Open Source Vulnerabilities) NVD OSV

影響パッケージ

Linux Kernel

[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"4.9.320"}]},{"type":"ECOSYSTEM","events":[{"introduced":"4.10.0"},{"fixed":"4.14.285"}]},{"type":"ECOSYSTEM","events":[{"introduced":"4.11.0"},{"fixed":"4.19.249"}]},{"type":"ECOSYSTEM","events":[{"introduced":"4.15.0"},{"fixed":"5.4.200"}]},{"type":"ECOSYSTEM","events":[{"introduced":"4.20.0"},{"fixed":"5.10.124"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.5.0"},{"fixed":"5.15.49"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.18.6"}]}]

ディストリビューション別の修正状況

各ディストリビューションが公開している、この CVE の修正パッケージ

Debian DEBIAN-CVE-2022-49708 linux 修正版: 5.10.127-1
Ubuntu UBUNTU-CVE-2022-49708 linux-azure 修正版: 4.15.0-1153.168~14.04.1