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From:   Chao Yu <yuchao0@huawei.com>
To:     <jaegeuk@kernel.org>
CC:     <linux-f2fs-devel@lists.sourceforge.net>,
        <linux-kernel@vger.kernel.org>, <chao@kernel.org>,
        Chao Yu <yuchao0@huawei.com>
Subject: [PATCH v2] f2fs: fix to avoid accessing invalid fio in f2fs_allocate_data_block()
Date:   Fri, 2 Apr 2021 17:22:23 +0800
Message-ID: <20210402092223.115515-1-yuchao0@huawei.com>
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Callers may pass fio parameter with NULL value to f2fs_allocate_data_block(),
so we should make sure accessing fio's field after fio's validation check.

Fixes: f608c38c59c6 ("f2fs: clean up parameter of f2fs_allocate_data_block()")
Signed-off-by: Chao Yu <yuchao0@huawei.com>
---
v2:
- relocate fio->retry assignment to avoid race condition.
 fs/f2fs/segment.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
index c517e689a9a3..44897cfecb1e 100644
--- a/fs/f2fs/segment.c
+++ b/fs/f2fs/segment.c
@@ -3417,12 +3417,12 @@ void f2fs_allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
 		f2fs_inode_chksum_set(sbi, page);
 	}
 
-	if (F2FS_IO_ALIGNED(sbi))
-		fio->retry = false;
-
 	if (fio) {
 		struct f2fs_bio_info *io;
 
+		if (F2FS_IO_ALIGNED(sbi))
+			fio->retry = false;
+
 		INIT_LIST_HEAD(&fio->list);
 		fio->in_list = true;
 		io = sbi->write_io[fio->type] + fio->temp;
-- 
2.29.2