From: Marcel Holtmann <marcel@holtmann.org>
To: BlueZ development <bluez-devel@lists.sourceforge.net>
In-Reply-To: <44E0F288.2000107@pracucci.com>
References: <44E0F288.2000107@pracucci.com>
Date: Tue, 15 Aug 2006 02:01:25 +0200
Message-Id: <1155600085.4075.36.camel@aeonflux.holtmann.net>
Mime-Version: 1.0
Subject: Re: [Bluez-devel] hcidump-1.30 segmentation fault
Reply-To: BlueZ development <bluez-devel@lists.sourceforge.net>
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Sender: bluez-devel-bounces@lists.sourceforge.net
Errors-To: bluez-devel-bounces@lists.sourceforge.net

Hi Marco,

> I get a segmentation fault when I dump an OBEX connection with hcidump
> 1.30 (I have not tried with 1.31). I have compiled hcidump with
> --enable-debug and debugged it with gdb. I have got the following backtrace:
> 
> 2006-08-14 21:59:11.118487 > ACL data: handle 8 flags 0x02 dlen 12
>     L2CAP(d): cid 0x0040 len 8 [psm 3]
>       RFCOMM(d): UIH: cr 0 dlci 6 pf 1 ilen 3 fcs 0x49 credits 2
>         OBEX: Connect rsp(f): status 100 len 3 version 11.7 flags 136
> mtu 18681
>         Status 100 = Continue
> 
> (gdb) bt
> #0  parse_headers (level=3, frm=0x8066e78) at parser.h:157
> #1  0x080562f4 in obex_dump (level=3, frm=0x8066e78) at obex.c:323
> #2  0x08052d83 in rfcomm_dump (level=2, frm=0xbf85ae50) at rfcomm.c:325
> #3  0x08049285 in process_frames (dev=0, sock=6, fd=-1, flags=4864) at
> parser.h:245
> #4  0x0804a565 in main (argc=-1, argv=0xbf85af9c) at hcidump.c:850
> 
> The problem seems to be in obex_dump() function at row 273:
> 
> case 0x00:    /* Connect */
>             version = get_u8(frm);
>             flags   = get_u8(frm);
>             pktlen  = get_u16(frm);
>             printf(" version %d.%d flags %d mtu %d\n",
>                 version >> 4, version & 0xf, flags, pktlen);
>             break;
> 
> Before to enter the "case" above, frm->len is set to 0... so, get_u*
> calls decrease the frm->len to 4294967292 and the next call to
> parse_headers() fails.

this should not happen, because the connect header must include these
parameters. However we should not segfault. It is better to simple stop
processing. Added patch to the CVS repository.

Regards

Marcel


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