Commit 19ebc1e6 authored by Su Hui's avatar Su Hui Committed by Steve French
Browse files

smb: client: fix possible double free in smb2_set_ea() 



Clang static checker(scan-build) warning：
fs/smb/client/smb2ops.c:1304:2: Attempt to free released memory.
 1304 |         kfree(ea);
      |         ^~~~~~~~~

There is a double free in such case:
'ea is initialized to NULL' -> 'first successful memory allocation for
ea' -> 'something failed, goto sea_exit' -> 'first memory release for ea'
-> 'goto replay_again' -> 'second goto sea_exit before allocate memory
for ea' -> 'second memory release for ea resulted in double free'.

Re-initialie 'ea' to NULL near to the replay_again label, it can fix this
double free problem.

Fixes: 4f1fffa2 ("cifs: commands that are retried should have replay flag set")
Reviewed-by: default avatarDan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: default avatarSu Hui <suhui@nfschina.com>
Signed-off-by: default avatarSteve French <stfrench@microsoft.com>
parent 8e929cb5

fs/smb/client/smb2ops.c

+2 −1
Original line number Diff line number Diff line
@@ -1158,7 +1158,7 @@ smb2_set_ea(const unsigned int xid, struct cifs_tcon *tcon, 
	struct cifs_fid fid;

	unsigned int size[1];

	void *data[1];

	struct smb2_file_full_ea_info *ea = NULL;

	struct smb2_file_full_ea_info *ea;

	struct smb2_query_info_rsp *rsp;

	int rc, used_len = 0;

	int retries = 0, cur_sleep = 1;
@@ -1179,6 +1179,7 @@ smb2_set_ea(const unsigned int xid, struct cifs_tcon *tcon, 
	if (!utf16_path)

		return -ENOMEM;



	ea = NULL;

	resp_buftype[0] = resp_buftype[1] = resp_buftype[2] = CIFS_NO_BUFFER;

	vars = kzalloc(sizeof(*vars), GFP_KERNEL);

	if (!vars) {