linux-kernel.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
* KMSAN: uninit-value in br_dev_xmit
@ 2020-02-24  8:38 syzbot
  2020-02-24  8:51 ` Nikolay Aleksandrov
  2020-02-24  9:47 ` syzbot
  0 siblings, 2 replies; 3+ messages in thread
From: syzbot @ 2020-02-24  8:38 UTC (permalink / raw)
  To: bridge, davem, glider, kuba, linux-kernel, netdev, nikolay,
	roopa, syzkaller-bugs

Hello,

syzbot found the following crash on:

HEAD commit:    8bbbc5cf kmsan: don't compile memmove
git tree:       https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=14d9a3d9e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=cd0e9a6b0e555cc3
dashboard link: https://syzkaller.appspot.com/bug?extid=18c8b623c66fc198c493
compiler:       clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
userspace arch: i386

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+18c8b623c66fc198c493@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in br_dev_xmit+0x99a/0x1730 net/bridge/br_device.c:64
CPU: 0 PID: 14704 Comm: syz-executor.1 Not tainted 5.6.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x220 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
 br_dev_xmit+0x99a/0x1730 net/bridge/br_device.c:64
 __netdev_start_xmit include/linux/netdevice.h:4524 [inline]
 netdev_start_xmit include/linux/netdevice.h:4538 [inline]
 xmit_one net/core/dev.c:3470 [inline]
 dev_hard_start_xmit+0x531/0xab0 net/core/dev.c:3486
 __dev_queue_xmit+0x37de/0x4220 net/core/dev.c:4063
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4096
 __bpf_tx_skb net/core/filter.c:2061 [inline]
 __bpf_redirect_common net/core/filter.c:2100 [inline]
 __bpf_redirect+0x11d5/0x1440 net/core/filter.c:2107
 ____bpf_clone_redirect net/core/filter.c:2140 [inline]
 bpf_clone_redirect+0x466/0x620 net/core/filter.c:2112
 bpf_prog_a481c1313990ee2c+0x5e0/0x1000
 bpf_dispatcher_nopfunc include/linux/bpf.h:521 [inline]
 bpf_test_run+0x60c/0xe50 net/bpf/test_run.c:48
 bpf_prog_test_run_skb+0xcab/0x24a0 net/bpf/test_run.c:388
 bpf_prog_test_run kernel/bpf/syscall.c:2572 [inline]
 __do_sys_bpf+0xa684/0x13510 kernel/bpf/syscall.c:3414
 __se_sys_bpf kernel/bpf/syscall.c:3355 [inline]
 __ia32_sys_bpf+0xdb/0x120 kernel/bpf/syscall.c:3355
 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline]
 do_fast_syscall_32+0x3c7/0x6e0 arch/x86/entry/common.c:410
 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f79d99
Code: 90 e8 0b 00 00 00 f3 90 0f ae e8 eb f9 8d 74 26 00 89 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f5d740cc EFLAGS: 00000296 ORIG_RAX: 0000000000000165
RAX: ffffffffffffffda RBX: 000000000000000a RCX: 0000000020000140
RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127
 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:82
 slab_alloc_node mm/slub.c:2793 [inline]
 __kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4401
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 pskb_expand_head+0x20b/0x1b00 net/core/skbuff.c:1629
 skb_ensure_writable+0x3ea/0x490 net/core/skbuff.c:5453
 __bpf_try_make_writable net/core/filter.c:1635 [inline]
 bpf_try_make_writable net/core/filter.c:1641 [inline]
 bpf_try_make_head_writable net/core/filter.c:1649 [inline]
 ____bpf_clone_redirect net/core/filter.c:2134 [inline]
 bpf_clone_redirect+0x251/0x620 net/core/filter.c:2112
 bpf_prog_a481c1313990ee2c+0x5e0/0x1000
 bpf_dispatcher_nopfunc include/linux/bpf.h:521 [inline]
 bpf_test_run+0x60c/0xe50 net/bpf/test_run.c:48
 bpf_prog_test_run_skb+0xcab/0x24a0 net/bpf/test_run.c:388
 bpf_prog_test_run kernel/bpf/syscall.c:2572 [inline]
 __do_sys_bpf+0xa684/0x13510 kernel/bpf/syscall.c:3414
 __se_sys_bpf kernel/bpf/syscall.c:3355 [inline]
 __ia32_sys_bpf+0xdb/0x120 kernel/bpf/syscall.c:3355
 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline]
 do_fast_syscall_32+0x3c7/0x6e0 arch/x86/entry/common.c:410
 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139
=====================================================


---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: KMSAN: uninit-value in br_dev_xmit
  2020-02-24  8:38 KMSAN: uninit-value in br_dev_xmit syzbot
@ 2020-02-24  8:51 ` Nikolay Aleksandrov
  2020-02-24  9:47 ` syzbot
  1 sibling, 0 replies; 3+ messages in thread
From: Nikolay Aleksandrov @ 2020-02-24  8:51 UTC (permalink / raw)
  To: syzbot, bridge, davem, glider, kuba, linux-kernel, netdev, roopa,
	syzkaller-bugs

On 24/02/2020 10:38, syzbot wrote:
> Hello,
> 
> syzbot found the following crash on:
> 
> HEAD commit:    8bbbc5cf kmsan: don't compile memmove
> git tree:       https://github.com/google/kmsan.git master
> console output: https://syzkaller.appspot.com/x/log.txt?x=14d9a3d9e00000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=cd0e9a6b0e555cc3
> dashboard link: https://syzkaller.appspot.com/bug?extid=18c8b623c66fc198c493
> compiler:       clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
> userspace arch: i386
> 
> Unfortunately, I don't have any reproducer for this crash yet.
> 
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+18c8b623c66fc198c493@syzkaller.appspotmail.com
> 

br_allowed_ingress() can call skb_vlan_untag() which does pskb_may_pull() and so
the cached eth header can become invalid.
I'll prepare a fix.

Cheers,
 Nik

> =====================================================
> BUG: KMSAN: uninit-value in br_dev_xmit+0x99a/0x1730 net/bridge/br_device.c:64
> CPU: 0 PID: 14704 Comm: syz-executor.1 Not tainted 5.6.0-rc2-syzkaller #0
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
> Call Trace:
>  __dump_stack lib/dump_stack.c:77 [inline]
>  dump_stack+0x1c9/0x220 lib/dump_stack.c:118
>  kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
>  __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
>  br_dev_xmit+0x99a/0x1730 net/bridge/br_device.c:64
>  __netdev_start_xmit include/linux/netdevice.h:4524 [inline]
>  netdev_start_xmit include/linux/netdevice.h:4538 [inline]
>  xmit_one net/core/dev.c:3470 [inline]
>  dev_hard_start_xmit+0x531/0xab0 net/core/dev.c:3486
>  __dev_queue_xmit+0x37de/0x4220 net/core/dev.c:4063
>  dev_queue_xmit+0x4b/0x60 net/core/dev.c:4096
>  __bpf_tx_skb net/core/filter.c:2061 [inline]
>  __bpf_redirect_common net/core/filter.c:2100 [inline]
>  __bpf_redirect+0x11d5/0x1440 net/core/filter.c:2107
>  ____bpf_clone_redirect net/core/filter.c:2140 [inline]
>  bpf_clone_redirect+0x466/0x620 net/core/filter.c:2112
>  bpf_prog_a481c1313990ee2c+0x5e0/0x1000
>  bpf_dispatcher_nopfunc include/linux/bpf.h:521 [inline]
>  bpf_test_run+0x60c/0xe50 net/bpf/test_run.c:48
>  bpf_prog_test_run_skb+0xcab/0x24a0 net/bpf/test_run.c:388
>  bpf_prog_test_run kernel/bpf/syscall.c:2572 [inline]
>  __do_sys_bpf+0xa684/0x13510 kernel/bpf/syscall.c:3414
>  __se_sys_bpf kernel/bpf/syscall.c:3355 [inline]
>  __ia32_sys_bpf+0xdb/0x120 kernel/bpf/syscall.c:3355
>  do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline]
>  do_fast_syscall_32+0x3c7/0x6e0 arch/x86/entry/common.c:410
>  entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139
> RIP: 0023:0xf7f79d99
> Code: 90 e8 0b 00 00 00 f3 90 0f ae e8 eb f9 8d 74 26 00 89 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
> RSP: 002b:00000000f5d740cc EFLAGS: 00000296 ORIG_RAX: 0000000000000165
> RAX: ffffffffffffffda RBX: 000000000000000a RCX: 0000000020000140
> RDX: 0000000000000040 RSI: 0000000000000000 RDI: 0000000000000000
> RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
> R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
> 
> Uninit was created at:
>  kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
>  kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127
>  kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:82
>  slab_alloc_node mm/slub.c:2793 [inline]
>  __kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4401
>  __kmalloc_reserve net/core/skbuff.c:142 [inline]
>  pskb_expand_head+0x20b/0x1b00 net/core/skbuff.c:1629
>  skb_ensure_writable+0x3ea/0x490 net/core/skbuff.c:5453
>  __bpf_try_make_writable net/core/filter.c:1635 [inline]
>  bpf_try_make_writable net/core/filter.c:1641 [inline]
>  bpf_try_make_head_writable net/core/filter.c:1649 [inline]
>  ____bpf_clone_redirect net/core/filter.c:2134 [inline]
>  bpf_clone_redirect+0x251/0x620 net/core/filter.c:2112
>  bpf_prog_a481c1313990ee2c+0x5e0/0x1000
>  bpf_dispatcher_nopfunc include/linux/bpf.h:521 [inline]
>  bpf_test_run+0x60c/0xe50 net/bpf/test_run.c:48
>  bpf_prog_test_run_skb+0xcab/0x24a0 net/bpf/test_run.c:388
>  bpf_prog_test_run kernel/bpf/syscall.c:2572 [inline]
>  __do_sys_bpf+0xa684/0x13510 kernel/bpf/syscall.c:3414
>  __se_sys_bpf kernel/bpf/syscall.c:3355 [inline]
>  __ia32_sys_bpf+0xdb/0x120 kernel/bpf/syscall.c:3355
>  do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline]
>  do_fast_syscall_32+0x3c7/0x6e0 arch/x86/entry/common.c:410
>  entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139
> =====================================================
> 
> 
> ---
> This bug is generated by a bot. It may contain errors.
> See https://goo.gl/tpsmEJ for more information about syzbot.
> syzbot engineers can be reached at syzkaller@googlegroups.com.
> 
> syzbot will keep track of this bug report. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> 


^ permalink raw reply	[flat|nested] 3+ messages in thread

* Re: KMSAN: uninit-value in br_dev_xmit
  2020-02-24  8:38 KMSAN: uninit-value in br_dev_xmit syzbot
  2020-02-24  8:51 ` Nikolay Aleksandrov
@ 2020-02-24  9:47 ` syzbot
  1 sibling, 0 replies; 3+ messages in thread
From: syzbot @ 2020-02-24  9:47 UTC (permalink / raw)
  To: bridge, davem, glider, kuba, linux-kernel, netdev, nikolay,
	roopa, syzkaller-bugs

syzbot has found a reproducer for the following crash on:

HEAD commit:    8bbbc5cf kmsan: don't compile memmove
git tree:       https://github.com/google/kmsan.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=1508df95e00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=cd0e9a6b0e555cc3
dashboard link: https://syzkaller.appspot.com/bug?extid=18c8b623c66fc198c493
compiler:       clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81)
userspace arch: i386
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=166ecc81e00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16b103ede00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+18c8b623c66fc198c493@syzkaller.appspotmail.com

=====================================================
BUG: KMSAN: uninit-value in br_dev_xmit+0x99a/0x1730 net/bridge/br_device.c:64
CPU: 0 PID: 11855 Comm: syz-executor414 Not tainted 5.6.0-rc2-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1c9/0x220 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
 br_dev_xmit+0x99a/0x1730 net/bridge/br_device.c:64
 __netdev_start_xmit include/linux/netdevice.h:4524 [inline]
 netdev_start_xmit include/linux/netdevice.h:4538 [inline]
 xmit_one net/core/dev.c:3470 [inline]
 dev_hard_start_xmit+0x531/0xab0 net/core/dev.c:3486
 __dev_queue_xmit+0x37de/0x4220 net/core/dev.c:4063
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4096
 __bpf_tx_skb net/core/filter.c:2061 [inline]
 __bpf_redirect_common net/core/filter.c:2100 [inline]
 __bpf_redirect+0x11d5/0x1440 net/core/filter.c:2107
 ____bpf_clone_redirect net/core/filter.c:2140 [inline]
 bpf_clone_redirect+0x466/0x620 net/core/filter.c:2112
 bpf_prog_a481c1313990ee2c+0x554/0x1000
 bpf_dispatcher_nopfunc include/linux/bpf.h:521 [inline]
 bpf_test_run+0x60c/0xe50 net/bpf/test_run.c:48
 bpf_prog_test_run_skb+0xcab/0x24a0 net/bpf/test_run.c:388
 bpf_prog_test_run kernel/bpf/syscall.c:2572 [inline]
 __do_sys_bpf+0xa684/0x13510 kernel/bpf/syscall.c:3414
 __se_sys_bpf kernel/bpf/syscall.c:3355 [inline]
 __ia32_sys_bpf+0xdb/0x120 kernel/bpf/syscall.c:3355
 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline]
 do_fast_syscall_32+0x3c7/0x6e0 arch/x86/entry/common.c:410
 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f39d99
Code: 90 e8 0b 00 00 00 f3 90 0f ae e8 eb f9 8d 74 26 00 89 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000ff88460c EFLAGS: 00000246 ORIG_RAX: 0000000000000165
RAX: ffffffffffffffda RBX: 000000000000000a RCX: 0000000020000040
RDX: 0000000000000040 RSI: 0000000000000000 RDI: 000000000000005b
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127
 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:82
 slab_alloc_node mm/slub.c:2793 [inline]
 __kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4401
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 pskb_expand_head+0x20b/0x1b00 net/core/skbuff.c:1629
 skb_ensure_writable+0x3ea/0x490 net/core/skbuff.c:5453
 __bpf_try_make_writable net/core/filter.c:1635 [inline]
 bpf_try_make_writable net/core/filter.c:1641 [inline]
 bpf_try_make_head_writable net/core/filter.c:1649 [inline]
 ____bpf_clone_redirect net/core/filter.c:2134 [inline]
 bpf_clone_redirect+0x251/0x620 net/core/filter.c:2112
 bpf_prog_a481c1313990ee2c+0x554/0x1000
 bpf_dispatcher_nopfunc include/linux/bpf.h:521 [inline]
 bpf_test_run+0x60c/0xe50 net/bpf/test_run.c:48
 bpf_prog_test_run_skb+0xcab/0x24a0 net/bpf/test_run.c:388
 bpf_prog_test_run kernel/bpf/syscall.c:2572 [inline]
 __do_sys_bpf+0xa684/0x13510 kernel/bpf/syscall.c:3414
 __se_sys_bpf kernel/bpf/syscall.c:3355 [inline]
 __ia32_sys_bpf+0xdb/0x120 kernel/bpf/syscall.c:3355
 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline]
 do_fast_syscall_32+0x3c7/0x6e0 arch/x86/entry/common.c:410
 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139
=====================================================


^ permalink raw reply	[flat|nested] 3+ messages in thread

end of thread, other threads:[~2020-02-24  9:47 UTC | newest]

Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-02-24  8:38 KMSAN: uninit-value in br_dev_xmit syzbot
2020-02-24  8:51 ` Nikolay Aleksandrov
2020-02-24  9:47 ` syzbot

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).