| Message ID | 1303819401-14789-3-git-send-email-jlayton@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Jeff Layton <jlayton@redhat.com> wrote: > It's possible that when we go to decode the string area in the > SESSION_SETUP response, that bytes_remaining will be 0. Decrementing it at > that point will mean that it can go "negative" and wrap. Check for a > bytes_remaining value of 0, and don't try to decode the string area if > that's the case. > > Cc: stable@kernel.org > Reported-by: David Howells <dhowells@redhat.com> > Signed-off-by: Jeff Layton <jlayton@redhat.com> Acked-by: David Howells <dhowells@redhat.com> -- To unsubscribe from this list: send the line "unsubscribe linux-cifs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/cifs/sess.c b/fs/cifs/sess.c index 2e2c911..645114a 100644 --- a/fs/cifs/sess.c +++ b/fs/cifs/sess.c @@ -916,7 +916,9 @@ ssetup_ntlmssp_authenticate: } /* BB check if Unicode and decode strings */ - if (smb_buf->Flags2 & SMBFLG2_UNICODE) { + if (bytes_remaining == 0) { + /* no string area to decode, do nothing */ + } else if (smb_buf->Flags2 & SMBFLG2_UNICODE) { /* unicode string area must be word-aligned */ if (((unsigned long) bcc_ptr - (unsigned long) smb_buf) % 2) { ++bcc_ptr;
It's possible that when we go to decode the string area in the SESSION_SETUP response, that bytes_remaining will be 0. Decrementing it at that point will mean that it can go "negative" and wrap. Check for a bytes_remaining value of 0, and don't try to decode the string area if that's the case. Cc: stable@kernel.org Reported-by: David Howells <dhowells@redhat.com> Signed-off-by: Jeff Layton <jlayton@redhat.com> --- fs/cifs/sess.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-)