Date: Tue, 28 Nov 2000 15:59:26 -0800 (PST) From: FengYue <fengyue@bluerose.windmoon.nu> To: Alfred Perlstein <bright@wintelcom.net> Cc: Bosko Milekic <bmilekic@technokratis.com>, hackers@FreeBSD.ORG Subject: Re: crash on 4.2-stable (sendto() system call) Message-ID: <Pine.BSF.4.21.0011281504180.54354-100000@shell.unixbox.com> In-Reply-To: <Pine.BSF.4.21.0011231515050.12930-100000@shell.unixbox.com>
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On Thu, 23 Nov 2000, FengYue wrote: ->dmesg: kvm_read: ->--- ->#6 0xc01882dd in fr_makefrip (hlen=20, ip=0xc0a48fe4, fin=0xd892fb0c) -> at ../../netinet/fil.c:258 ->#7 0xc018e20c in fr_checkicmpmatchingstate (ip=0xc0a48fc8, ->fin=0xd892fc1c) -> at ../../netinet/ip_state.c:1081 Hi, I'm looking at ip_state.c and fr_makefrip.c, there is one thing I don't quiet understand and see if any of you could explain a bit to me: in ip_state.c:973, it declares fr_info_t ofin on the function stack -- apearly uninit'ed, then at line 1081 it calls fr_makefrip(...,...,&ofin); (ofin is not init'ed in anyway before calling fr_makefrip() at line 1081) in fil.c:202, fr_makefrip(), it does some assignments to elements in *fin which points to &ofin in ip_state.c:1081, anyway, fin is not init'ed and later in fr_makefrip():227 it checks for fin->fin_v which contains the IP version, obviously I think fin->fin_v is some garbage at this point and if it happened to have value '6' in fin_v, then V6 code will be executed and thus would cause a panic at line fil.c:258 just like what shows in the GDB trace. Did I find the bug causing the panic or did I miss something? As I mentioned in my previous E-mail, a machine of mine crashed 10 hours after upgrading to 4.2-stable. After the crash I commented out an IPFW ruleset which basically allows icmp type 0 & 11 to be in, until now the machine has not experienced a panic. Thanks To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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