Re: Memory modified after free, seemingly geli related

On Wed, Aug 05, 2015 at 03:24:26AM +0000, Ed Maste wrote:
> I've encountered a few memory modified after free panics recently,
> which seem to be from geli. I don't yet have any debugging to
> completely confirm it's geli, but it has not happened on my other test
> laptop which configured similarly but without geli.
> 
> This has a few local patches from my to-commit-to-HEAD queue.
> FreeBSD volta 11.0-CURRENT FreeBSD 11.0-CURRENT #10
> r284409+6a002d9(staging): Tue Jul  7 17:57:01 EDT 2015
> 
> panic: Memory modified after free 0xfffff80009d504d8(248) val=0 _at_
> 0xfffff80009d50518

I'm seeing it too. I tracked it down to ZFS. The bio was last owned by
the ZFS::VDEV GEOM class, which is modyfing bio_error on freed bio. I'm
investigating further and will let you know here once I find the
cause.

> cpuid = 1
> KDB: stack backtrace:
> db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame 0xfffffe011414a880
> vpanic() at vpanic+0x189/frame 0xfffffe011414a900
> panic() at panic+0x43/frame 0xfffffe011414a960
> trash_ctor() at trash_ctor+0x48/frame 0xfffffe011414a970
> uma_zalloc_arg() at uma_zalloc_arg+0x573/frame 0xfffffe011414a9e0
> g_clone_bio() at g_clone_bio+0x1d/frame 0xfffffe011414aa00
> g_eli_start() at g_eli_start+0xbd/frame 0xfffffe011414aa30
> g_io_schedule_down() at g_io_schedule_down+0xe6/frame 0xfffffe011414aa60
> g_down_procbody() at g_down_procbody+0x7d/frame 0xfffffe011414aa70
> fork_exit() at fork_exit+0x84/frame 0xfffffe011414aab0
> fork_trampoline() at fork_trampoline+0xe/frame 0xfffffe011414aab0
> --- trap 0, rip = 0, rsp = 0xfffffe011414ab70, rbp = 0 ---

-- 
Pawel Jakub Dawidek                       http://www.wheelsystems.com
FreeBSD committer                         http://www.FreeBSD.org
Am I Evil? Yes, I Am!                     http://mobter.com