From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-pf0-f195.google.com ([209.85.192.195]:42066 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752375AbeEGJdy (ORCPT ); Mon, 7 May 2018 05:33:54 -0400 Received: by mail-pf0-f195.google.com with SMTP id p14so11029730pfh.9 for ; Mon, 07 May 2018 02:33:54 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <1525682589.6049.4.camel@sipsolutions.net> References: <0000000000000390eb056b77596d@google.com> <20180505164041.GD7746@kroah.com> <095bc684-0029-0b2e-5e28-23376174ca02@gmail.com> <20180505220721.GA10829@kroah.com> <1525682589.6049.4.camel@sipsolutions.net> From: Dmitry Vyukov Date: Mon, 7 May 2018 11:33:33 +0200 Message-ID: (sfid-20180507_113416_319080_383644FD) Subject: Re: WARNING in kernfs_add_one To: Johannes Berg Cc: Greg KH , linux-wireless@vger.kernel.org, Eric Dumazet , netdev , syzbot , LKML , syzkaller-bugs , Tejun Heo Content-Type: text/plain; charset="UTF-8" Sender: linux-wireless-owner@vger.kernel.org List-ID: On Mon, May 7, 2018 at 10:43 AM, Johannes Berg wrote: > On Sat, 2018-05-05 at 15:07 -0700, Greg KH wrote: > >> > > > syzbot found the following crash on: > > Maybe it should learn to differentiate warnings, if it's going to set > panic_on_warn :-) How? Note that this is not specific to syzbot. If you see WARNINGs in a subsystem that you have no idea about (or you just a normal user), what do you do? Right, you report it to maintainers. > I get why, but still, at least differentiating in the emails wouldn't be > bad. Well, the subject says "WARNING". But note there are _very_ bad WARNINGs too. Generally, a WARNING means a kernel bug just that kernel can tolerate without bringing the system down (as opposed to BUG). >> > > > kernfs: ns required in 'ieee80211' for 'phy3' > > Huh. What does that even mean? > >> > > > RIP: 0010:kernfs_add_one+0x406/0x4d0 fs/kernfs/dir.c:758 >> > > > RSP: 0018:ffff8801ca9eece0 EFLAGS: 00010286 >> > > > RAX: 000000000000002d RBX: ffffffff87d5cee0 RCX: ffffffff8160ba7d >> > > > RDX: 0000000000000000 RSI: ffffffff81610731 RDI: ffff8801ca9ee840 >> > > > RBP: ffff8801ca9eed20 R08: ffff8801d9538500 R09: 0000000000000006 >> > > > R10: ffff8801d9538500 R11: 0000000000000000 R12: ffff8801ad1cb6c0 >> > > > R13: ffffffff885da640 R14: 0000000000000020 R15: 0000000000000000 >> > > > kernfs_create_link+0x112/0x180 fs/kernfs/symlink.c:41 >> > > > sysfs_do_create_link_sd.isra.2+0x90/0x130 fs/sysfs/symlink.c:43 >> > > > sysfs_do_create_link fs/sysfs/symlink.c:79 [inline] >> > > > sysfs_create_link+0x65/0xc0 fs/sysfs/symlink.c:91 >> > > > device_add_class_symlinks drivers/base/core.c:1612 [inline] >> > > > device_add+0x7a0/0x16d0 drivers/base/core.c:1810 >> > > > wiphy_register+0x178a/0x2430 net/wireless/core.c:806 >> > > > ieee80211_register_hw+0x13cd/0x35d0 net/mac80211/main.c:1047 >> > > > mac80211_hwsim_new_radio+0x1d9b/0x3410 >> > > > drivers/net/wireless/mac80211_hwsim.c:2772 >> > > > hwsim_new_radio_nl+0x7a7/0xa60 drivers/net/wireless/mac80211_hwsim.c:3246 >> > > > genl_family_rcv_msg+0x889/0x1120 net/netlink/genetlink.c:599 > > Basically we're creating a new virtual radio, which in turn creates a > new device, which we have to register. > > Something is going on with the context here that makes sysfs unhappy, > but TBH I have no idea what. > > johannes > > -- > You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. > To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/1525682589.6049.4.camel%40sipsolutions.net. > For more options, visit https://groups.google.com/d/optout.