On Sat, 13 Jan 2024 23:06:02 +0800 Gao Xiang <[email protected]> wrote:
> 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: <[email protected]> > Fixes: 8f89926290c4 ("erofs: get compression algorithms directly on mapping") > Fixes: 622ceaddb764 ("erofs: lzma compression support") > Reviewed-by: Yue Hu <[email protected]> > Signed-off-by: Gao Xiang <[email protected]> LGTM. Reviewed-by: Yue Hu <[email protected]>
