From e87f7329bbd6760c2acc4f1eb423362b08851a71 Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Wed, 23 Nov 2016 10:51:17 -0800 Subject: [PATCH] f2fs: fix overflow due to condition check order In the last ilen case, i was already increased, resulting in accessing out- of-boundary entry of do_replace and blkaddr. Fix to check ilen first to exit the loop. Fixes: 2aa8fbb9693020 ("f2fs: refactor __exchange_data_block for speed up") Cc: stable@vger.kernel.org # 4.8+ Signed-off-by: Jaegeuk Kim --- fs/f2fs/file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index c7865073cd26..02372175725d 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -967,7 +967,7 @@ static int __clone_blkaddrs(struct inode *src_inode, struct inode *dst_inode, new_size = (dst + i) << PAGE_SHIFT; if (dst_inode->i_size < new_size) f2fs_i_size_write(dst_inode, new_size); - } while ((do_replace[i] || blkaddr[i] == NULL_ADDR) && --ilen); + } while (--ilen && (do_replace[i] || blkaddr[i] == NULL_ADDR)); f2fs_put_dnode(&dn); } else { -- 2.20.1