From: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx> [ Upstream commit 1dd73601a1cba37a0ed5f89a8662c90191df5873 ] 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/000000000000ac8efa05e7feaa1f@xxxxxxxxxx Reported-by: syzbot+f966c13b1b4fc0403b19@xxxxxxxxxxxxxxxxxxxxxxxxx Fixes: 431339ba9042 ("staging: erofs: add inode operations") Reviewed-by: Yue Hu <huyue2@xxxxxxxxxxx> Link: https://lore.kernel.org/r/20220909023948.28925-1-hsiangkao@xxxxxxxxxxxxxxxxx Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- 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 95a403720e8c..16cf9a283557 100644 --- a/fs/erofs/inode.c +++ b/fs/erofs/inode.c @@ -214,7 +214,7 @@ static int erofs_fill_symlink(struct inode *inode, void *kaddr, /* if it cannot be handled with fast symlink scheme */ if (vi->datalayout != EROFS_INODE_FLAT_INLINE || - inode->i_size >= EROFS_BLKSIZ) { + inode->i_size >= EROFS_BLKSIZ || inode->i_size < 0) { inode->i_op = &erofs_symlink_iops; return 0; } -- 2.35.1
