diff options
| author | Gao Xiang <hsiangkao@linux.alibaba.com> | 2024-01-13 23:06:02 +0800 |
|---|---|---|
| committer | Gao Xiang <hsiangkao@linux.alibaba.com> | 2024-01-13 23:58:08 +0800 |
| commit | 118a8cf504d7dfa519562d000f423ee3ca75d2c4 (patch) | |
| tree | 234b9fca62aa49309c6ebf19ec8c82e422858e0b /fs/erofs/decompressor.c | |
| parent | 0dd3ee31125508cd67f7e7172247f05b7fd1753a (diff) | |
erofs: fix inconsistent per-file compression format
EROFS can select compression algorithms on a per-file basis, and each
per-file compression algorithm needs to be marked in the on-disk
superblock for initialization.
However, syzkaller can generate inconsistent crafted images that use
an unsupported algorithmtype for specific inodes, e.g. use MicroLZMA
algorithmtype even it's not set in `sbi->available_compr_algs`. This
can lead to an unexpected "BUG: kernel NULL pointer dereference" if
the corresponding decompressor isn't built-in.
Fix this by checking against `sbi->available_compr_algs` for each
m_algorithmformat request. Incorrect !erofs_sb_has_compr_cfgs preset
bitmap is now fixed together since it was harmless previously.
Reported-by: <bugreport@ubisectech.com>
Fixes: 8f89926290c4 ("erofs: get compression algorithms directly on mapping")
Fixes: 622ceaddb764 ("erofs: lzma compression support")
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Link: https://lore.kernel.org/r/20240113150602.1471050-1-hsiangkao@linux.alibaba.com
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Diffstat (limited to 'fs/erofs/decompressor.c')
| -rw-r--r-- | fs/erofs/decompressor.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c index 021be5feb1bc..af98e88908ee 100644 --- a/fs/erofs/decompressor.c +++ b/fs/erofs/decompressor.c @@ -398,7 +398,7 @@ int z_erofs_parse_cfgs(struct super_block *sb, struct erofs_super_block *dsb) int size, ret = 0; if (!erofs_sb_has_compr_cfgs(sbi)) { - sbi->available_compr_algs = Z_EROFS_COMPRESSION_LZ4; + sbi->available_compr_algs = 1 << Z_EROFS_COMPRESSION_LZ4; return z_erofs_load_lz4_config(sb, dsb, NULL, 0); } |