Re: WARNING in kobject_add_internal

[Dmitry Vyukov]

On Tue, Oct 31, 2017 at 3:54 PM, syzbot
<bot+e204ced820ef739d71ef5438f5e1976a874abc8d@xxxxxxxxxxxxxxxxxxxxxxxxx>
wrote:
> Hello,
>
> syzkaller hit the following crash on
> 833e0e2f24fd0525090878f71e129a8a4cb8bf78
> git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git/master
> compiler: gcc (GCC) 7.1.1 20170620
> .config is attached
> Raw console output is attached.
>
>
>
>
> kobject_add_internal failed for brport (error: -12 parent: syz6)
> ------------[ cut here ]------------
> WARNING: CPU: 1 PID: 3485 at lib/kobject.c:244
> kobject_add_internal+0x3f6/0xbc0 lib/kobject.c:242
> Kernel panic - not syncing: panic_on_warn set ...
>
> CPU: 1 PID: 3485 Comm: syz-executor6 Not tainted 4.14.0-rc4+ #80
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> Call Trace:
>  __dump_stack lib/dump_stack.c:16 [inline]
>  dump_stack+0x194/0x257 lib/dump_stack.c:52
>  panic+0x1e4/0x417 kernel/panic.c:181
>  __warn+0x1c4/0x1d9 kernel/panic.c:542
>  report_bug+0x211/0x2d0 lib/bug.c:183
>  fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:178
>  do_trap_no_signal arch/x86/kernel/traps.c:212 [inline]
>  do_trap+0x260/0x390 arch/x86/kernel/traps.c:261
>  do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:298
>  do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:311
>  invalid_op+0x18/0x20 arch/x86/entry/entry_64.S:905
> RIP: 0010:kobject_add_internal+0x3f6/0xbc0 lib/kobject.c:242
> RSP: 0018:ffff8801bf816900 EFLAGS: 00010282
> RAX: 0000000000000040 RBX: ffff8801c09b4620 RCX: 0000000000000000
> RDX: 0000000000000040 RSI: ffffffff8158d38e RDI: ffffed0037f02d14
> RBP: ffff8801bf8169f8 R08: ffff8801bf816070 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000000 R12: 1ffff10037f02d26
> R13: 00000000fffffff4 R14: ffff8801cb9b0b30 R15: ffff8801cd01c000
>  kobject_add_varg lib/kobject.c:366 [inline]
>  kobject_init_and_add+0xf9/0x150 lib/kobject.c:438
>  br_add_if+0x786/0x1990 net/bridge/br_if.c:533
>  br_add_slave+0x29/0x30 net/bridge/br_device.c:349
>  do_set_master+0x19c/0x1f0 net/core/rtnetlink.c:1986
>  do_setlink+0xa98/0x38e0 net/core/rtnetlink.c:2119
>  rtnl_newlink+0xf0d/0x1a40 net/core/rtnetlink.c:2661
>  rtnetlink_rcv_msg+0x733/0x1090 net/core/rtnetlink.c:4301
>  netlink_rcv_skb+0x216/0x440 net/netlink/af_netlink.c:2409
>  rtnetlink_rcv+0x1c/0x20 net/core/rtnetlink.c:4313
>  netlink_unicast_kernel net/netlink/af_netlink.c:1273 [inline]
>  netlink_unicast+0x4e8/0x6f0 net/netlink/af_netlink.c:1299
>  netlink_sendmsg+0xa4a/0xe70 net/netlink/af_netlink.c:1862
>  sock_sendmsg_nosec net/socket.c:633 [inline]
>  sock_sendmsg+0xca/0x110 net/socket.c:643
>  sock_write_iter+0x320/0x5e0 net/socket.c:912
>  call_write_iter include/linux/fs.h:1770 [inline]
>  do_iter_readv_writev+0x531/0x7f0 fs/read_write.c:673
>  do_iter_write+0x15a/0x540 fs/read_write.c:952
>  vfs_writev+0x18a/0x340 fs/read_write.c:997
>  do_writev+0xfc/0x2a0 fs/read_write.c:1032
>  SYSC_writev fs/read_write.c:1105 [inline]
>  SyS_writev+0x27/0x30 fs/read_write.c:1102
>  entry_SYSCALL_64_fastpath+0x1f/0xbe
> RIP: 0033:0x4520a9
> RSP: 002b:00007f4633db3c08 EFLAGS: 00000216 ORIG_RAX: 0000000000000014
> RAX: ffffffffffffffda RBX: 0000000000718000 RCX: 00000000004520a9
> RDX: 0000000000000001 RSI: 00000000205d9000 RDI: 0000000000000005
> RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000216 R12: 00000000004b6c37
> R13: 00007f4633db3b48 R14: 00000000004b6c47 R15: 0000000000000000
> Dumping ftrace buffer:
>    (ftrace buffer empty)
> Kernel Offset: disabled
> Rebooting in 86400 seconds..

Seems to be related to the preceding kmalloc failure.

> ---
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