[patch] alignment trap in hcid

Frédéric Dalleau <[email protected]>
Newsgroups gmane.linux.bluez.devel
Message-ID <[email protected]>
Dear all,

I recently met an alignment trap in hcid.
Some device sent me an sdp request and the answer had to be fragmented 
because the device reception buffer was very small.
After that i saw alignment trap.
The last trace I saw was : Continuation state size: 8
The trace is located at sdpd/request.c : static sdp_cont_state_t 
*sdp_cstate_get(uint8_t *buffer)
This function returns an unaligned pointer.

I think this patch is ok, but it has never been tested, and possibly 
other problems are hidden behind.
Instead of returning an unaligned pointer, the patch allocates a buffer.

To test it, i could build a bluez with small sdp reception buffer and 
ask an arm to give me fragmented reply.
This would save me some time if someone could tell me where to change 
this value...

BR,
Frederic

-------------------------------------------------------------------------
This SF.net email is sponsored by: Microsoft
Defy all challenges. Microsoft(R) Visual Studio 2008.
http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/

_______________________________________________
Bluez-devel mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/bluez-devel
upf_hcid_align.patch (text/x-patch, 1.1 KB)
diff --git a/sdpd/request.c b/sdpd/request.c
index 20e68b6..f7952f5 100644
--- a/sdpd/request.c
+++ b/sdpd/request.c
@@ -179,7 +179,8 @@ static sdp_cont_state_t *sdp_cstate_get(uint8_t *buffer)
 
 	pdata += sizeof(uint8_t);
 	if (cStateSize != 0) {
-		sdp_cont_state_t *cstate = (sdp_cont_state_t *)pdata;
+		sdp_cont_state_t *cstate = malloc(sizeof(sdp_cont_state_t));
+		memcpy(cstate, (sdp_cont_state_t *)pdata, sizeof(sdp_cont_state_t));
 		debug("Cstate TS : 0x%lx", cstate->timestamp);
 		debug("Bytes sent : %d", cstate->cStateValue.maxBytesSent);
 		return cstate;
@@ -408,6 +409,8 @@ static int service_search_req(sdp_req_t *req, sdp_buf_t *buf)
 	}
 
 done:	
+	if(cstate)
+		free(cstate);
 	if (pattern)
 		sdp_list_free(pattern, free);
 
@@ -593,6 +596,8 @@ static int service_attr_req(sdp_req_t *req, sdp_buf_t *buf)
 	buf->buf_size += sizeof(uint16_t);
 
 done:
+	if(cstate)
+		free(cstate);
 	if (seq)
                 sdp_list_free(seq, free);
 	if (status)
@@ -754,6 +759,8 @@ static int service_search_attr_req(sdp_req_t *req, sdp_buf_t *buf)
 	}
 
 done:
+	if(cstate)
+		free(cstate);
 	if (tmpbuf.data)
 		free(tmpbuf.data);
 	if (pattern)
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.