Date: Fri, 11 Aug 2006 11:46:24 +0200 From: Jeremie Le Hen <jeremie@le-hen.org> To: Ulf Zimmermann <ulf@Alameda.net> Cc: hackers@freebsd.org Subject: Re: [fbsd] sshd throwing signal 6 (sigabrt) Message-ID: <20060811094623.GA39702@obiwan.tataz.chchile.org> In-Reply-To: <20060718221415.GI45191@evil.alameda.net> References: <20060718221415.GI45191@evil.alameda.net>
next in thread | previous in thread | raw e-mail | index | archive | help
Hi Ulf, On Tue, Jul 18, 2006 at 03:14:16PM -0700, Ulf Zimmermann wrote: > I have a FreeBSD server (was 5.4-prerelease, now 6-stable as of noon PDT). > On this server I got a problem with sshd throwing signal 6: > > Jul 18 15:04:03 log01 sshd[66161]: debug2: User child is on pid 66163 > Jul 18 15:04:03 log01 sshd[66163]: debug3: PAM: opening session > Jul 18 15:04:03 log01 sshd[66163]: debug1: PAM: reinitializing credentials > Jul 18 15:04:03 log01 sshd[66163]: debug2: set_newkeys: mode 0 > Jul 18 15:04:03 log01 sshd[66163]: debug2: set_newkeys: mode 1 > Jul 18 15:04:03 log01 sshd[66163]: debug1: Entering interactive session for SSH2. > Jul 18 15:04:03 log01 sshd[66163]: debug2: fd 5 setting O_NONBLOCK > Jul 18 15:04:03 log01 sshd[66163]: debug2: fd 6 setting O_NONBLOCK > Jul 18 15:04:03 log01 sshd[66163]: debug1: server_init_dispatch_20 > Jul 18 15:04:03 log01 sshd[66163]: debug1: server_input_channel_open: ctype session rchan 0 win 131072 max 32768 > Jul 18 15:04:03 log01 sshd[66163]: debug1: input_session_request > Jul 18 15:04:03 log01 sshd[66163]: debug1: channel 0: new [server-session] > Jul 18 15:04:03 log01 sshd[66163]: debug1: session_new: init > Jul 18 15:04:03 log01 sshd[66163]: debug1: session_new: session 0 > Jul 18 15:04:03 log01 sshd[66163]: debug1: session_open: channel 0 > Jul 18 15:04:03 log01 sshd[66163]: debug1: session_open: session 0: link with channel 0 > Jul 18 15:04:03 log01 sshd[66163]: debug1: server_input_channel_open: confirm session > Jul 18 15:04:03 log01 sshd[66163]: debug1: server_input_channel_req: channel 0 request exec reply 0 > Jul 18 15:04:03 log01 sshd[66163]: debug1: session_by_channel: session 0 channel 0 > Jul 18 15:04:03 log01 sshd[66163]: debug1: session_input_channel_req: session 0 req exec > Jul 18 15:04:03 log01 sshd[66163]: debug2: fd 8 setting O_NONBLOCK > Jul 18 15:04:03 log01 sshd[66163]: debug3: fd 8 is O_NONBLOCK > Jul 18 15:04:03 log01 sshd[66163]: debug2: fd 10 setting O_NONBLOCK > Jul 18 15:04:03 log01 sshd[66163]: debug2: channel 0: rcvd eof > Jul 18 15:04:03 log01 sshd[66163]: debug2: channel 0: output open -> drain > Jul 18 15:04:03 log01 sshd[66163]: debug2: channel 0: obuf empty > Jul 18 15:04:03 log01 sshd[66163]: debug2: channel 0: close_write > Jul 18 15:04:03 log01 sshd[66163]: debug2: channel 0: output drain -> closed > Jul 18 15:04:03 log01 pid 66163 (sshd), uid 10042: exited on signal 6 > > About 80 servers have two cronjobs each starting at the full hour. Each > cronjob has a random sleep of 0 to 900 seconds before it executes ssh/scp/rsync > to copy one or multiple files to that FreeBSD server. One cronjob copies > one file ranging in size 30KB to 300KB. The other cronjob copies 10-30 > RRD files, ranging in size from 200KB to 1MB. > > Of these about 160 ssh connections in a time range of 15 minutes, I get > 1 to 10 errors at the end of the connection. All files get copied as far > I can tell but when the connection closes I see the above signal 6. > > On the source side of the ssh connection I get error messages like > > "Connection to xxxx closed by remote host" > "ssh_exchange_identification: Connection closed by remote host lost connection" > > Anyone have an idea what the problem could be that sshd see sigabrt? % obiwan:openssh$ grep -rl SIGABRT . | wc -l % 0 This should come from one of the underlying librairies sshd(8) is linked to. Do you run by chance 6-STABLE with ProPolice/SSP patch ? If a stack-based buffer overflow is detected, SIGABRT (signal 6) will be sent to the faulty process. Regards, -- Jeremie Le Hen < jeremie at le-hen dot org >< ttz at chchile dot org >
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20060811094623.GA39702>