[PATCH] erofs: fix double free of 'copied'

Gao Xiang hsiangkao at linux.alibaba.com
Wed Aug 25 22:07:57 AEST 2021

Dan reported a new smatch warning [1]
"fs/erofs/inode.c:210 erofs_read_inode() error: double free of 'copied'"

Due to new chunk-based format handling logic, the error path can be
called after kfree(copied).

Set "copied = NULL" after kfree(copied) to fix this.

[1] https://lore.kernel.org/r/202108251030.bELQozR7-lkp@intel.com
Fixes: c5aa903a59db ("erofs: support reading chunk-based uncompressed files")
Reported-by: kernel test robot <lkp at intel.com>
Reported-by: Dan Carpenter <dan.carpenter at oracle.com>
Signed-off-by: Gao Xiang <hsiangkao at linux.alibaba.com>
 fs/erofs/inode.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/erofs/inode.c b/fs/erofs/inode.c
index 4408929bd6f5..31ac3a73b390 100644
--- a/fs/erofs/inode.c
+++ b/fs/erofs/inode.c
@@ -127,6 +127,7 @@ static struct page *erofs_read_inode(struct inode *inode,
 			/* fill chunked inode summary info */
 			vi->chunkformat = le16_to_cpu(die->i_u.c.format);
+		copied = NULL;
 		vi->inode_isize = sizeof(struct erofs_inode_compact);

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