commit 1dd73601a1cba37a0ed5f89a8662c90191df5873 upstream. As syzbot reported [1], the root cause is that i_size field is a signed type, and negative i_size is also less than EROFS_BLKSIZ. As a consequence, it's handled as fast symlink unexpectedly.
Let's fall back to the generic path to deal with such unusual i_size. [1] https://lore.kernel.org/r/[email protected] Reported-by: [email protected] Fixes: 431339ba9042 ("staging: erofs: add inode operations") Reviewed-by: Yue Hu <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Gao Xiang <[email protected]> --- fs/erofs/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c index 0a94a52a119f..93a4ed665d93 100644 --- a/fs/erofs/inode.c +++ b/fs/erofs/inode.c @@ -202,7 +202,7 @@ static int erofs_fill_symlink(struct inode *inode, void *data, /* if it cannot be handled with fast symlink scheme */ if (vi->datalayout != EROFS_INODE_FLAT_INLINE || - inode->i_size >= PAGE_SIZE) { + inode->i_size >= PAGE_SIZE || inode->i_size < 0) { inode->i_op = &erofs_symlink_iops; return 0; } -- 2.43.5
