From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: WARNING: kobject bug in netdev_queue_update_kobjects Date: Mon, 05 Mar 2018 10:21:41 -0800 Message-ID: <1520274101.109662.7.camel@gmail.com> References: <001a113ac54eb1617d0566ae146d@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit To: syzbot , adobriyan@gmail.com, davem@davemloft.net, decot@googlers.com, dwindsor@gmail.com, elena.reshetova@intel.com, fw@strlen.de, ktkhai@virtuozzo.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, roopa@cumulusnetworks.com, stephen@networkplumber.org, syzkaller-bugs@googlegroups.com, xiyou.wangcong@gmail.com Return-path: In-Reply-To: <001a113ac54eb1617d0566ae146d@google.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Mon, 2018-03-05 at 09:59 -0800, syzbot wrote: > Hello, > > syzbot hit the following crash on upstream commit > 661e50bc853209e41a5c14a290ca4decc43cbfd1 (Sun Mar 4 22:54:11 2018 > +0000) > Linux 4.16-rc4 > > So far this crash happened 2 times on upstream. > C reproducer is attached. > syzkaller reproducer is attached. > Raw console output is attached. > compiler: gcc (GCC) 7.1.1 20170620 > .config is attached. > > IMPORTANT: if you fix the bug, please add the following tag to the > commit: > Reported-by: syzbot+7fb6d9525a4528104e05@syzkaller.appspotmail.com > It will help syzbot understand when the bug is fixed. See footer > for   > details. > If you forward the report, please keep this part and the footer. > > RBP: 00007ffd67c73e10 R08: 0000000000000001 R09: 00007ffd67c70032 > R10: 0000000000000000 R11: 0000000000000246 R12: 74656e2f7665642f > R13: ffffffffffffffff R14: 0000000000000008 R15: 0000000000000000 > ------------[ cut here ]------------ > kobject_add_internal failed for tx-3 (error: -12 parent: queues) > WARNING: CPU: 1 PID: 4119 at lib/kobject.c:242   > kobject_add_internal+0x3f6/0xbc0 lib/kobject.c:240 > Kernel panic - not syncing: panic_on_warn set ... > > CPU: 1 PID: 4119 Comm: syzkaller952529 Not tainted 4.16.0-rc4+ #341 > Hardware name: Google Google Compute Engine/Google Compute Engine, > BIOS   > Google 01/01/2011 > Call Trace: >   __dump_stack lib/dump_stack.c:17 [inline] >   dump_stack+0x194/0x24d lib/dump_stack.c:53 >   panic+0x1e4/0x41c kernel/panic.c:183 >   __warn+0x1dc/0x200 kernel/panic.c:547 >   report_bug+0x211/0x2d0 lib/bug.c:184 >   fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:178 >   fixup_bug arch/x86/kernel/traps.c:247 [inline] >   do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:296 >   do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:315 >   invalid_op+0x1b/0x40 arch/x86/entry/entry_64.S:986 > RIP: 0010:kobject_add_internal+0x3f6/0xbc0 lib/kobject.c:240 > RSP: 0018:ffff8801d2d9f488 EFLAGS: 00010286 > RAX: dffffc0000000008 RBX: ffff8801d1ec0618 RCX: ffffffff815abb7e > RDX: 0000000000000000 RSI: 1ffff1003a5b3e41 RDI: 1ffff1003a5b3e16 > RBP: ffff8801d2d9f580 R08: 1ffff1003a5b3dd8 R09: 0000000000000000 > R10: ffff8801d2d9f248 R11: 0000000000000000 R12: 1ffff1003a5b3e97 > R13: 00000000fffffff4 R14: ffff8801d0ce8d48 R15: ffffffff8684c720 >   kobject_add_varg lib/kobject.c:364 [inline] >   kobject_init_and_add+0xf9/0x150 lib/kobject.c:436 >   netdev_queue_add_kobject net/core/net-sysfs.c:1332 [inline] >   netdev_queue_update_kobjects+0x148/0x480 net/core/net-sysfs.c:1360 >   netif_set_real_num_tx_queues+0x185/0x790 net/core/dev.c:2397 >   tun_set_real_num_queues drivers/net/tun.c:638 [inline] >   tun_attach+0x7bd/0x1220 drivers/net/tun.c:863 >   tun_set_queue drivers/net/tun.c:2750 [inline] >   __tun_chr_ioctl+0x8f5/0x40d0 drivers/net/tun.c:2814 >   tun_chr_ioctl+0x2a/0x40 drivers/net/tun.c:3084 >   vfs_ioctl fs/ioctl.c:46 [inline] >   do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:686 >   SYSC_ioctl fs/ioctl.c:701 [inline] >   SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 >   do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 >   entry_SYSCALL_64_after_hwframe+0x42/0xb7 > RIP: 0033:0x444229 > RSP: 002b:00007ffd67c73e08 EFLAGS: 00000246 ORIG_RAX: > 0000000000000010 > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000444229 > RDX: 0000000020000200 RSI: 00000000400454d9 RDI: 0000000000000006 > RBP: 00007ffd67c73e10 R08: 0000000000000001 R09: 00007ffd67c70032 > R10: 0000000000000000 R11: 0000000000000246 R12: 74656e2f7665642f > R13: ffffffffffffffff R14: 0000000000000008 R15: 0000000000000000 > Dumping ftrace buffer: >     (ftrace buffer empty) > Kernel Offset: disabled > Rebooting in 86400 seconds.. > > > --- > This bug is generated by a dumb bot. It may contain errors. > See https://goo.gl/tpsmEJ for details. > Direct all questions to syzkaller@googlegroups.com. > > syzbot will keep track of this bug report. > If you forgot to add the Reported-by tag, once the fix for this bug > is   > merged > into any tree, please reply to this email with: > #syz fix: exact-commit-title > If you want to test a patch for this bug, please reply with: > #syz test: git://repo/address.git branch > and provide the patch inline or as an attachment. > To mark this as a duplicate of another syzbot report, please reply > with: > #syz dup: exact-subject-of-another-report > If it's a one-off invalid bug report, please reply with: > #syz invalid > Note: if the crash happens again, it will cause creation of a new > bug   > report. > Note: all commands must start from beginning of the line in the email > body. kobject_init_internal() simply is noisy when an error happen (in this case a memory allocation error was injected) It seems it is intended. commit 282029c005e65ffdce3aa9f8220f88a8bbbc4dae Author: Dan Williams Date:   Fri Apr 6 13:41:15 2012 -0700     kobject: provide more diagnostic info for kobject_add_internal() failures          1/ convert open-coded KERN_ERR+dump_stack() to WARN(), so that automated        tools pick up this warning.          2/ include the 'child' and 'parent' kobject names.  This information was        useful for tracking down the case where scsi invoked device_del() on a        parent object and subsequently invoked device_add() on a child.  Now the        warning looks like:               kobject_add_internal failed for target8:0:16 (error: -2 parent: end_device-8:0:24)          Pid: 2942, comm: scsi_scan_8 Not tainted 3.3.0-rc7-isci+ #2          Call Trace:           [] kobject_add_internal+0x1c1/0x1f3           [] ? trace_hardirqs_on+0xd/0xf           [] kobject_add_varg+0x41/0x50           [] kobject_add+0x64/0x66           [] device_add+0x12d/0x63a           [] ? kobject_put+0x4c/0x50           [] scsi_sysfs_add_sdev+0x4e/0x28a           [] do_scan_async+0x9c/0x145          Cc: Greg Kroah-Hartman     Cc: James Bottomley     Signed-off-by: Dan Williams     Signed-off-by: Greg Kroah-Hartman