On Wed, Feb 14, 2018 at 06:49:19PM +0200, Denys Fedoryshchenko wrote: > On 2018-02-14 18:47, Guillaume Nault wrote: > > On Wed, Feb 14, 2018 at 06:29:34PM +0200, Denys Fedoryshchenko wrote: > > > On 2018-02-14 18:07, Guillaume Nault wrote: > > > > On Wed, Feb 14, 2018 at 03:17:23PM +0200, Denys Fedoryshchenko wrote: > > > > > Hi, > > > > > > > > > > Upgraded kernel to 4.15.3, still it crashes after while (several > > > > > hours, > > > > > cannot do bisect, as it is production server). > > > > > > > > > > dev ppp # gdb ppp_generic.o > > > > > GNU gdb (Gentoo 7.12.1 vanilla) 7.12.1 > > > > > <<skipped>> > > > > > Reading symbols from ppp_generic.o...done. > > > > > (gdb) list *ppp_push+0x73 > > > > > 0x681 is in ppp_push (drivers/net/ppp/ppp_generic.c:1663). > > > > > 1658 list = list->next; > > > > > 1659 pch = list_entry(list, struct channel, clist); > > > > > 1660 > > > > > 1661 spin_lock(&pch->downl); > > > > > 1662 if (pch->chan) { > > > > > 1663 if > > > > > (pch->chan->ops->start_xmit(pch->chan, skb)) > > > > > 1664 ppp->xmit_pending = NULL; > > > > > 1665 } else { > > > > > 1666 /* channel got unregistered */ > > > > > 1667 kfree_skb(skb); > > > > > > > > > > > > > > I expect a memory corruption. Do you have the possibility to run with > > > > KASAN by any chance? > > > I will try to enable it tonight. For now i reverted "drivers, net, > > > ppp: > > > convert ppp_file.refcnt from atomic_t to refcount_t" for test. > > > > > This commit looks good to me. Do you have doubts about it because it's > > new in 4.15? Does it mean that your last known-good kernel is 4.14? > > I am just doing "manual" bisect, checking all possibilities, and picking > patch to revert randomly. > Must be a painful process. Are all of your networking modules required? With luck, you might be able to isolate a faulty module in fewer steps.
> Yes, correct, my known-good is 4.14.2. > Good to know. Let me know if you can get a KASAN trace.