From 3ef34e983d79746d47c5a894d5325e1a8618dc7a Mon Sep 17 00:00:00 2001 From: Jeremy Allison Date: Tue, 19 Sep 2017 16:11:33 -0700 Subject: [PATCH 1/2] s3: smbd: Fix SMB1 use-after-free crash bug. CVE-2017-14746 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit When setting up the chain, always use 'next->' variables not the 'req->' one. Bug discovered by 连一汉 CVE-2017-14746 BUG: https://bugzilla.samba.org/show_bug.cgi?id=13041 Signed-off-by: Jeremy Allison --- source3/smbd/process.c | 7 ++++--- source3/smbd/reply.c | 5 +++++ 2 files changed, 9 insertions(+), 3 deletions(-) diff --git a/source3/smbd/process.c b/source3/smbd/process.c index 656f1c0a667..2641894d1d7 100644 --- a/source3/smbd/process.c +++ b/source3/smbd/process.c @@ -1854,12 +1854,13 @@ void smb_request_done(struct smb_request *req) next->vuid = SVAL(req->outbuf, smb_uid); next->tid = SVAL(req->outbuf, smb_tid); - status = smb1srv_tcon_lookup(req->xconn, req->tid, + status = smb1srv_tcon_lookup(req->xconn, next->tid, now, &tcon); + if (NT_STATUS_IS_OK(status)) { - req->conn = tcon->compat; + next->conn = tcon->compat; } else { - req->conn = NULL; + next->conn = NULL; } next->chain_fsp = req->chain_fsp; next->inbuf = req->inbuf; diff --git a/source3/smbd/reply.c b/source3/smbd/reply.c index a40ff81b240..26918b6d9d5 100644 --- a/source3/smbd/reply.c +++ b/source3/smbd/reply.c @@ -921,6 +921,11 @@ void reply_tcon_and_X(struct smb_request *req) } TALLOC_FREE(tcon); + /* + * This tree id is gone. Make sure we can't re-use it + * by accident. + */ + req->tid = 0; } if ((passlen > MAX_PASS_LEN) || (passlen >= req->buflen)) { -- 2.11.0 From 3a6b1baeb84ada35745109a11dacab328a1d6a5b Mon Sep 17 00:00:00 2001 From: Jeremy Allison Date: Wed, 20 Sep 2017 11:04:50 -0700 Subject: [PATCH 2/2] s3: smbd: Chain code can return uninitialized memory when talloc buffer is grown. Ensure we zero out unused grown area. CVE-2017-15275 BUG: https://bugzilla.samba.org/show_bug.cgi?id=13077 Signed-off-by: Jeremy Allison --- source3/smbd/srvstr.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/source3/smbd/srvstr.c b/source3/smbd/srvstr.c index 56dceba8c6c..c2d70b32c32 100644 --- a/source3/smbd/srvstr.c +++ b/source3/smbd/srvstr.c @@ -110,6 +110,20 @@ ssize_t message_push_string(uint8_t **outbuf, const char *str, int flags) DEBUG(0, ("srvstr_push failed\n")); return -1; } + + /* + * Ensure we clear out the extra data we have + * grown the buffer by, but not written to. + */ + if (buf_size + result < buf_size) { + return -1; + } + if (grow_size < result) { + return -1; + } + + memset(tmp + buf_size + result, '\0', grow_size - result); + set_message_bcc((char *)tmp, smb_buflen(tmp) + result); *outbuf = tmp; -- 2.11.0