Messages in this thread Patch in this message | | | From | Pan Bian <> | Subject | [PATCH] freevxfs: set bp to NULL after dropping its reference in loop | Date | Sun, 25 Nov 2018 09:49:17 +0800 |
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The function vxfs_bmap_indir calls brelse(bh) in the loop and tries to start the next iteration. However, if it happens to break the loop, brelse(bp) will be called again. Resulting in a potential double free bug. This patch assigns NULL to bh after dropping its reference in the loop body.
Signed-off-by: Pan Bian <bianpan2016@163.com> --- fs/freevxfs/vxfs_bmap.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/fs/freevxfs/vxfs_bmap.c b/fs/freevxfs/vxfs_bmap.c index 1fd41cf..136e5d1 100644 --- a/fs/freevxfs/vxfs_bmap.c +++ b/fs/freevxfs/vxfs_bmap.c @@ -150,6 +150,7 @@ vxfs_bmap_indir(struct inode *ip, long indir, int size, long block) if (block < off) { brelse(bp); + bp = NULL; continue; } @@ -186,6 +187,7 @@ vxfs_bmap_indir(struct inode *ip, long indir, int size, long block) BUG(); } brelse(bp); + bp = NULL; } fail: -- 2.7.4
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