Date: Fri, 20 Dec 2002 00:48:33 +0000 (GMT) From: Gavin Atkinson <gavin@ury.york.ac.uk> To: current@FreeBSD.ORG Subject: Re: Panic: memory modified after free Message-ID: <20021220004330.J83600-100000@ury.york.ac.uk> In-Reply-To: <20021219151949.Y54430-100000@ury.york.ac.uk> References: <20021219151949.Y54430-100000@ury.york.ac.uk>
next in thread | previous in thread | raw e-mail | index | archive | help
On Thu, 19 Dec 2002, Gavin Atkinson wrote: > Running 5.0-RC as of yesterday on i386. background fsck was in progress, > but other than that system was idle. Logged in as root on the console, had > cd'd to a ports directory. (note that it panics almost instantly when > using the console, but lasts upto 10 minutes when in use over ssh) > Running "make deinstall" triggered this panic: > > Memory modified after free 0xc1891c00(1020) > panic: Most recently used by none >[snip backtrace] > The machine seems perfectly stable in single user mode. It also seems > pretty stable at the moment with linux emulation, usbd, sendmail, ipv6, > nfs server and moused enables commented out of rc.conf. I will try to add > one at a time tonight to determine which is at fault. Update: I re-cvsupped (to 19 Dec 14:00 GMT) , and recompiled world and kernel. I can no longer cause the panic. I then (out of interest) dropped back to the old kernel that was panicing (18 Dec 12:00 GMT), but run with the new world, and could not recreate the panic. I therefore believe that one of the userland binaries that I replaced was tickling the bug, and now I have replaced that binary, the problem no longer occurs. So, unless anyone can think of a better reason for this, I suspect there is a kernel use-after-free bug laying dormant. Gavin To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20021220004330.J83600-100000>