The corresponding patch has been merged in the 4.19 branch and is released as 4.19.29.
commit b4d965a37d89cd8611984ea16c85903d01ac967a Author: Ronnie Sahlberg <lsahl...@redhat.com> AuthorDate: Wed Oct 24 11:50:33 2018 +1000 Commit: Greg Kroah-Hartman <gre...@linuxfoundation.org> CommitDate: Wed Mar 13 14:02:40 2019 -0700 cifs: allow calling SMB2_xxx_free(NULL) commit 32a1fb36f6e50183871c2c1fcf5493c633e84732 upstream. Change these free functions to allow passing NULL as the argument and treat it as a no-op just like free(NULL) would. Or, if rqst->rq_iov is NULL. The second scenario could happen for smb2_queryfs() if the call to SMB2_query_info_init() fails and we go to qfs_exit to clean up and free all resources. In that case we have not yet assigned rqst.rq_iov and thus the rq_iov dereference in SMB2_close_free() will cause a NULL pointer dereference. [ bp: upstream patch also fixes SMB2_set_info_free which was introduced in 4.20 ] Fixes: 1eb9fb52040f ("cifs: create SMB2_open_init()/SMB2_open_free() helpers") Signed-off-by: Ronnie Sahlberg <lsahl...@redhat.com> Signed-off-by: Steve French <stfre...@microsoft.com> Reviewed-by: Aurelien Aptel <aap...@suse.com> CC: Stable <sta...@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>