From eb66b8abae98f869c224f7c852b685ae02144564 Mon Sep 17 00:00:00 2001
From: Lizhi Xu <lizhi.xu@windriver.com>
Date: Thu, 16 Nov 2023 11:13:52 +0800
Subject: [PATCH] squashfs: squashfs_read_data need to check if the length is 0
When the length passed in is 0, the pagemap_scan_test_walk() caller should
bail. This error causes at least a WARN_ON().
Link: https://lkml.kernel.org/r/20231116031352.40853-1-lizhi.xu@windriver.com
Reported-by: syzbot+32d3767580a1ea339a81@syzkaller.appspotmail.com
Closes: https://lkml.kernel.org/r/0000000000000526f2060a30a085@google.com
Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com>
Reviewed-by: Phillip Lougher <phillip@squashfs.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
fs/squashfs/block.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/squashfs/block.c b/fs/squashfs/block.c
index 581ce95193390..2dc730800f448 100644
--- a/fs/squashfs/block.c
+++ b/fs/squashfs/block.c
@@ -321,7 +321,7 @@ int squashfs_read_data(struct super_block *sb, u64 index, int length,
TRACE("Block @ 0x%llx, %scompressed size %d\n", index - 2,
compressed ? "" : "un", length);
}
- if (length < 0 || length > output->length ||
+ if (length <= 0 || length > output->length ||
(index + length) > msblk->bytes_used) {
res = -EIO;
goto out;
--
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