From: Paulo Alcantara <pc@manguebit.com> stable inclusion from stable-v6.6.7 commit 5ac34ba42e9aba7fc82997f778802b954efced33 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8SSQ4 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 92414333eb375ed64f4ae92d34d579e826936480 upstream. If server returned no data for FSCTL_DFS_GET_REFERRALS, @dfs_rsp will remain NULL and then parse_dfs_referrals() will dereference it. Fix this by returning -EIO when no output data is returned. Besides, we can't fix it in SMB2_ioctl() as some FSCTLs are allowed to return no data as per MS-SMB2 2.2.32. Fixes: 9d49640a21bf ("CIFS: implement get_dfs_refer for SMB2+") Cc: stable@vger.kernel.org Reported-by: Robert Morris <rtm@csail.mit.edu> Signed-off-by: Paulo Alcantara (SUSE) <pc@manguebit.com> Signed-off-by: Steve French <stfrench@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com> --- fs/smb/client/smb2ops.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c index b2a60aa6564f..386b62d5c133 100644 --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -2834,6 +2834,8 @@ smb2_get_dfs_refer(const unsigned int xid, struct cifs_ses *ses, usleep_range(512, 2048); } while (++retry_count < 5); + if (!rc && !dfs_rsp) + rc = -EIO; if (rc) { if (!is_retryable_error(rc) && rc != -ENOENT && rc != -EOPNOTSUPP) cifs_tcon_dbg(VFS, "%s: ioctl error: rc=%d\n", __func__, rc); -- 2.20.1