This is a note to let you know that I've just added the patch titled
erofs: fix order >= MAX_ORDER warning due to crafted negative i_size
to the 5.15-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
erofs-fix-order-max_order-warning-due-to-crafted-neg.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 40a68780653bd91ebbf658469175f3e189cdd685
Author: Gao Xiang <xiang@xxxxxxxxxx>
Date: Fri Sep 9 10:39:48 2022 +0800
erofs: fix order >= MAX_ORDER warning due to crafted negative i_size
[ 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>
diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index a552399e211d..0c293ff6697b 100644
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -222,7 +222,7 @@ 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;
}
