Only regular inodes are allowed for file-backed mounts, not directories
(as seen in the original syzbot case) or special inodes.
Also ensure that .read_folio() is implemented on the underlying fs.
Fixes: fb176750266a ("erofs: add file-backed mount support")
Reported-by: syzbot+001306cd9c92ce0df...@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/r/00000000000011bdde0622498...@google.com
Signed-off-by: Gao Xiang <hsiang...@linux.alibaba.com>
---
fs/erofs/super.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/fs/erofs/super.c b/fs/erofs/super.c
index 666873f745da..7c3467dcc5b4 100644
--- a/fs/erofs/super.c
+++ b/fs/erofs/super.c
@@ -714,7 +714,10 @@ static int erofs_fc_get_tree(struct fs_context *fc)
if (IS_ERR(sbi->fdev))
return PTR_ERR(sbi->fdev);
- return get_tree_nodev(fc, erofs_fc_fill_super);
+ if (S_ISREG(file_inode(sbi->fdev)->i_mode) &&
+ sbi->fdev->f_mapping->a_ops->read_folio)
+ return get_tree_nodev(fc, erofs_fc_fill_super);
+ fput(sbi->fdev);
}
#endif
return ret;
--
2.43.5
