diff options
| author | Gao Xiang | 2024-03-04 11:53:39 +0800 |
|---|---|---|
| committer | Gao Xiang | 2024-03-07 10:21:00 +0800 |
| commit | 893e5e9b7369a02e7ceaa6d98db6739162005b03 (patch) | |
| tree | ba940e04acedfc268fbf41548dc388965faa22a1 | |
| parent | 90d35da658da8cff0d4ecbb5113f5fac9d00eb72 (diff) | |
erofs: fix uninitialized page cache reported by KMSAN
syzbot reports a KMSAN reproducer [1] which generates a crafted
filesystem image and causes IMA to read uninitialized page cache.
Later, (rq->outputsize > rq->inputsize) will be formally supported
after either large uncompressed pclusters (> block size) or big
lclusters are landed. However, currently there is no way to generate
such filesystems by using mkfs.erofs.
Thus, let's mark this condition as unsupported for now.
[1] https://lore.kernel.org/r/0000000000002be12a0611ca7ff8@google.com
Reported-and-tested-by: syzbot+7bc44a489f0ef0670bd5@syzkaller.appspotmail.com
Fixes: 1ca01520148a ("erofs: refine z_erofs_transform_plain() for sub-page block support")
Reviewed-by: Sandeep Dhavale <dhavale@google.com>
Reviewed-by: Yue Hu <huyue2@coolpad.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
Link: https://lore.kernel.org/r/20240304035339.425857-1-hsiangkao@linux.alibaba.com
| -rw-r--r-- | fs/erofs/decompressor.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c index d4cee95af14c..2ec9b2bb628d 100644 --- a/fs/erofs/decompressor.c +++ b/fs/erofs/decompressor.c @@ -323,7 +323,8 @@ static int z_erofs_transform_plain(struct z_erofs_decompress_req *rq, unsigned int cur = 0, ni = 0, no, pi, po, insz, cnt; u8 *kin; - DBG_BUGON(rq->outputsize > rq->inputsize); + if (rq->outputsize > rq->inputsize) + return -EOPNOTSUPP; if (rq->alg == Z_EROFS_COMPRESSION_INTERLACED) { cur = bs - (rq->pageofs_out & (bs - 1)); pi = (rq->pageofs_in + rq->inputsize - cur) & ~PAGE_MASK; |