From: Gao Xiang Date: Sat, 29 Jun 2024 18:57:43 +0000 (+0800) Subject: erofs: ensure m_llen is reset to 0 if metadata is invalid X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=29e9518ea58ff1f3b881c5baf31be5c616509c4b;p=linux erofs: ensure m_llen is reset to 0 if metadata is invalid [ Upstream commit 9b32b063be1001e322c5f6e01f2a649636947851 ] Sometimes, the on-disk metadata might be invalid due to user interrupts, storage failures, or other unknown causes. In that case, z_erofs_map_blocks_iter() may still return a valid m_llen while other fields remain invalid (e.g., m_plen can be 0). Due to the return value of z_erofs_scan_folio() in some path will be ignored on purpose, the following z_erofs_scan_folio() could then use the invalid value by accident. Let's reset m_llen to 0 to prevent this. Link: https://lore.kernel.org/r/20240629185743.2819229-1-hsiangkao@linux.alibaba.com Signed-off-by: Gao Xiang Signed-off-by: Sasha Levin --- diff --git a/fs/erofs/zmap.c b/fs/erofs/zmap.c index e313c936351d..6bd435a565f6 100644 --- a/fs/erofs/zmap.c +++ b/fs/erofs/zmap.c @@ -723,6 +723,8 @@ int z_erofs_map_blocks_iter(struct inode *inode, struct erofs_map_blocks *map, err = z_erofs_do_map_blocks(inode, map, flags); out: + if (err) + map->m_llen = 0; trace_z_erofs_map_blocks_iter_exit(inode, map, flags, err); return err; }