Hello,
syzbot found the following crash on:
HEAD commit: 1d965c4d Merge branch 'Refactor-flower-classifier-to-remov..
git tree: net-next
console output: https://syzkaller.appspot.com/x/log.txt?x=14ff71df200000
kernel config: https://syzkaller.appspot.com/x/.config?x=f05902bca21d8935
dashboard link: https://syzkaller.appspot.com/bug?extid=aa9105f99c12b6abfe27
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
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: [email protected]
==================================================================
BUG: KASAN: use-after-free in atomic_read
include/asm-generic/atomic-instrumented.h:26 [inline]
BUG: KASAN: use-after-free in queued_spin_trylock
include/asm-generic/qspinlock.h:69 [inline]
BUG: KASAN: use-after-free in do_raw_spin_trylock+0x6a/0x180
kernel/locking/spinlock_debug.c:119
Read of size 4 at addr ffff88808a28ccd4 by task syz-executor.0/17585
CPU: 0 PID: 17585 Comm: syz-executor.0 Not tainted 5.0.0+ #105
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0x172/0x1f0 lib/dump_stack.c:113
print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
check_memory_region_inline mm/kasan/generic.c:185 [inline]
check_memory_region+0x123/0x190 mm/kasan/generic.c:191
kasan_check_read+0x11/0x20 mm/kasan/common.c:102
atomic_read include/asm-generic/atomic-instrumented.h:26 [inline]
queued_spin_trylock include/asm-generic/qspinlock.h:69 [inline]
do_raw_spin_trylock+0x6a/0x180 kernel/locking/spinlock_debug.c:119
__raw_spin_trylock include/linux/spinlock_api_smp.h:89 [inline]
_raw_spin_trylock+0x1c/0x80 kernel/locking/spinlock.c:128
spin_trylock include/linux/spinlock.h:339 [inline]
icmp_xmit_lock net/ipv4/icmp.c:219 [inline]
__icmp_send+0x553/0x1400 net/ipv4/icmp.c:666
icmp_send include/net/icmp.h:47 [inline]
ipv4_link_failure+0x31/0x210 net/ipv4/route.c:1190
dst_link_failure include/net/dst.h:416 [inline]
arp_error_report+0xd1/0x1c0 net/ipv4/arp.c:297
neigh_invalidate+0x24b/0x570 net/core/neighbour.c:995
neigh_timer_handler+0xc35/0xf30 net/core/neighbour.c:1081
call_timer_fn+0x190/0x720 kernel/time/timer.c:1325
expire_timers kernel/time/timer.c:1362 [inline]
__run_timers kernel/time/timer.c:1681 [inline]
__run_timers kernel/time/timer.c:1649 [inline]
run_timer_softirq+0x652/0x1700 kernel/time/timer.c:1694
__do_softirq+0x266/0x95a kernel/softirq.c:293
invoke_softirq kernel/softirq.c:374 [inline]
irq_exit+0x180/0x1d0 kernel/softirq.c:414
exiting_irq arch/x86/include/asm/apic.h:536 [inline]
smp_apic_timer_interrupt+0x14a/0x570 arch/x86/kernel/apic/apic.c:1062
apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
</IRQ>
RIP: 0010:filename_mountpoint+0x25d/0x3c0 fs/namei.c:2722
Code: 14 02 4c 89 e0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 1c 01 00 00
45 8b 24 24 31 ff 44 89 e6 e8 58 ea ba ff 45 85 e4 74 62 <e8> ce e8 ba ff
e8 49 2a fe ff 4c 89 f7 e8 81 f2 ff ff e8 bc e8 ba
RSP: 0018:ffff8880a857fc30 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: dffffc0000000000 RBX: 1ffff110150aff88 RCX: ffffffff81b57ad4
RDX: 1ffff1100bd8e54c RSI: ffffffff81b57ae2 RDI: ffff88805ec72a60
RBP: ffff8880a857fdc8 R08: ffff88805ec72300 R09: 0000000000000001
R10: 000000000000001c R11: ffff8880ae82de3b R12: 0000000000000000
R13: 0000000000000000 R14: ffff888097790e00 R15: ffff8880a857fe68
user_path_mountpoint_at+0x3a/0x50 fs/namei.c:2745
ksys_umount+0x167/0xf00 fs/namespace.c:1687
__do_sys_umount fs/namespace.c:1713 [inline]
__se_sys_umount fs/namespace.c:1711 [inline]
__x64_sys_umount+0x54/0x80 fs/namespace.c:1711
do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45ac57
Code: 44 00 00 b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 4d 8e fb ff c3
66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff
ff 0f 83 2d 8e fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffe6359ff08 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000045ac57
RDX: 0000000000402ea0 RSI: 0000000000000002 RDI: 00007ffe6359ffb0
RBP: 00000000000019e0 R08: 0000000000000000 R09: 000000000000000d
R10: 0000000000000006 R11: 0000000000000202 R12: 00007ffe635a1040
R13: 0000000000bfa940 R14: 0000000000000000 R15: 00007ffe635a1040
Allocated by task 12478:
save_stack+0x45/0xd0 mm/kasan/common.c:75
set_track mm/kasan/common.c:87 [inline]
__kasan_kmalloc mm/kasan/common.c:497 [inline]
__kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:470
kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:505
slab_post_alloc_hook mm/slab.h:436 [inline]
slab_alloc mm/slab.c:3392 [inline]
kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3554
getname_flags fs/namei.c:138 [inline]
getname_flags+0xd6/0x5b0 fs/namei.c:128
getname+0x1a/0x20 fs/namei.c:209
do_sys_open+0x2c9/0x5d0 fs/open.c:1057
__do_sys_open fs/open.c:1081 [inline]
__se_sys_open fs/open.c:1076 [inline]
__x64_sys_open+0x7e/0xc0 fs/open.c:1076
do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
Freed by task 12478:
save_stack+0x45/0xd0 mm/kasan/common.c:75
set_track mm/kasan/common.c:87 [inline]
__kasan_slab_free+0x102/0x150 mm/kasan/common.c:459
kasan_slab_free+0xe/0x10 mm/kasan/common.c:467
__cache_free mm/slab.c:3498 [inline]
kmem_cache_free+0x86/0x260 mm/slab.c:3764
putname+0xef/0x130 fs/namei.c:259
do_sys_open+0x318/0x5d0 fs/open.c:1072
__do_sys_open fs/open.c:1081 [inline]
__se_sys_open fs/open.c:1076 [inline]
__x64_sys_open+0x7e/0xc0 fs/open.c:1076
do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x49/0xbe
The buggy address belongs to the object at ffff88808a28c780
which belongs to the cache names_cache of size 4096
The buggy address is located 1364 bytes inside of
4096-byte region [ffff88808a28c780, ffff88808a28d780)
The buggy address belongs to the page:
page:ffffea000228a300 count:1 mapcount:0 mapping:ffff88812c2d8dc0 index:0x0
compound_mapcount: 0
flags: 0x1fffc0000010200(slab|head)
raw: 01fffc0000010200 ffffea00025c8908 ffffea0001840a08 ffff88812c2d8dc0
raw: 0000000000000000 ffff88808a28c780 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88808a28cb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88808a28cc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff88808a28cc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff88808a28cd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff88808a28cd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
---
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 [email protected].
syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
On Wed, Mar 27, 2019 at 9:19 AM syzbot
<[email protected]> wrote:
>
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: 1d965c4d Merge branch 'Refactor-flower-classifier-to-remov..
> git tree: net-next
> console output: https://syzkaller.appspot.com/x/log.txt?x=14ff71df200000
> kernel config: https://syzkaller.appspot.com/x/.config?x=f05902bca21d8935
> dashboard link: https://syzkaller.appspot.com/bug?extid=aa9105f99c12b6abfe27
> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
>
> 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: [email protected]
Eric, do you think this is also fixed by "tun: properly test for
IFF_UP" as the bug in icmp6_send?
> ==================================================================
> BUG: KASAN: use-after-free in atomic_read
> include/asm-generic/atomic-instrumented.h:26 [inline]
> BUG: KASAN: use-after-free in queued_spin_trylock
> include/asm-generic/qspinlock.h:69 [inline]
> BUG: KASAN: use-after-free in do_raw_spin_trylock+0x6a/0x180
> kernel/locking/spinlock_debug.c:119
> Read of size 4 at addr ffff88808a28ccd4 by task syz-executor.0/17585
>
> CPU: 0 PID: 17585 Comm: syz-executor.0 Not tainted 5.0.0+ #105
> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> Google 01/01/2011
> Call Trace:
> <IRQ>
> __dump_stack lib/dump_stack.c:77 [inline]
> dump_stack+0x172/0x1f0 lib/dump_stack.c:113
> print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
> kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
> check_memory_region_inline mm/kasan/generic.c:185 [inline]
> check_memory_region+0x123/0x190 mm/kasan/generic.c:191
> kasan_check_read+0x11/0x20 mm/kasan/common.c:102
> atomic_read include/asm-generic/atomic-instrumented.h:26 [inline]
> queued_spin_trylock include/asm-generic/qspinlock.h:69 [inline]
> do_raw_spin_trylock+0x6a/0x180 kernel/locking/spinlock_debug.c:119
> __raw_spin_trylock include/linux/spinlock_api_smp.h:89 [inline]
> _raw_spin_trylock+0x1c/0x80 kernel/locking/spinlock.c:128
> spin_trylock include/linux/spinlock.h:339 [inline]
> icmp_xmit_lock net/ipv4/icmp.c:219 [inline]
> __icmp_send+0x553/0x1400 net/ipv4/icmp.c:666
> icmp_send include/net/icmp.h:47 [inline]
> ipv4_link_failure+0x31/0x210 net/ipv4/route.c:1190
> dst_link_failure include/net/dst.h:416 [inline]
> arp_error_report+0xd1/0x1c0 net/ipv4/arp.c:297
> neigh_invalidate+0x24b/0x570 net/core/neighbour.c:995
> neigh_timer_handler+0xc35/0xf30 net/core/neighbour.c:1081
> call_timer_fn+0x190/0x720 kernel/time/timer.c:1325
> expire_timers kernel/time/timer.c:1362 [inline]
> __run_timers kernel/time/timer.c:1681 [inline]
> __run_timers kernel/time/timer.c:1649 [inline]
> run_timer_softirq+0x652/0x1700 kernel/time/timer.c:1694
> __do_softirq+0x266/0x95a kernel/softirq.c:293
> invoke_softirq kernel/softirq.c:374 [inline]
> irq_exit+0x180/0x1d0 kernel/softirq.c:414
> exiting_irq arch/x86/include/asm/apic.h:536 [inline]
> smp_apic_timer_interrupt+0x14a/0x570 arch/x86/kernel/apic/apic.c:1062
> apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
> </IRQ>
> RIP: 0010:filename_mountpoint+0x25d/0x3c0 fs/namei.c:2722
> Code: 14 02 4c 89 e0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 1c 01 00 00
> 45 8b 24 24 31 ff 44 89 e6 e8 58 ea ba ff 45 85 e4 74 62 <e8> ce e8 ba ff
> e8 49 2a fe ff 4c 89 f7 e8 81 f2 ff ff e8 bc e8 ba
> RSP: 0018:ffff8880a857fc30 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
> RAX: dffffc0000000000 RBX: 1ffff110150aff88 RCX: ffffffff81b57ad4
> RDX: 1ffff1100bd8e54c RSI: ffffffff81b57ae2 RDI: ffff88805ec72a60
> RBP: ffff8880a857fdc8 R08: ffff88805ec72300 R09: 0000000000000001
> R10: 000000000000001c R11: ffff8880ae82de3b R12: 0000000000000000
> R13: 0000000000000000 R14: ffff888097790e00 R15: ffff8880a857fe68
> user_path_mountpoint_at+0x3a/0x50 fs/namei.c:2745
> ksys_umount+0x167/0xf00 fs/namespace.c:1687
> __do_sys_umount fs/namespace.c:1713 [inline]
> __se_sys_umount fs/namespace.c:1711 [inline]
> __x64_sys_umount+0x54/0x80 fs/namespace.c:1711
> do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
> RIP: 0033:0x45ac57
> Code: 44 00 00 b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 4d 8e fb ff c3
> 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff
> ff 0f 83 2d 8e fb ff c3 66 2e 0f 1f 84 00 00 00 00
> RSP: 002b:00007ffe6359ff08 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
> RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000045ac57
> RDX: 0000000000402ea0 RSI: 0000000000000002 RDI: 00007ffe6359ffb0
> RBP: 00000000000019e0 R08: 0000000000000000 R09: 000000000000000d
> R10: 0000000000000006 R11: 0000000000000202 R12: 00007ffe635a1040
> R13: 0000000000bfa940 R14: 0000000000000000 R15: 00007ffe635a1040
>
> Allocated by task 12478:
> save_stack+0x45/0xd0 mm/kasan/common.c:75
> set_track mm/kasan/common.c:87 [inline]
> __kasan_kmalloc mm/kasan/common.c:497 [inline]
> __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:470
> kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:505
> slab_post_alloc_hook mm/slab.h:436 [inline]
> slab_alloc mm/slab.c:3392 [inline]
> kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3554
> getname_flags fs/namei.c:138 [inline]
> getname_flags+0xd6/0x5b0 fs/namei.c:128
> getname+0x1a/0x20 fs/namei.c:209
> do_sys_open+0x2c9/0x5d0 fs/open.c:1057
> __do_sys_open fs/open.c:1081 [inline]
> __se_sys_open fs/open.c:1076 [inline]
> __x64_sys_open+0x7e/0xc0 fs/open.c:1076
> do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> Freed by task 12478:
> save_stack+0x45/0xd0 mm/kasan/common.c:75
> set_track mm/kasan/common.c:87 [inline]
> __kasan_slab_free+0x102/0x150 mm/kasan/common.c:459
> kasan_slab_free+0xe/0x10 mm/kasan/common.c:467
> __cache_free mm/slab.c:3498 [inline]
> kmem_cache_free+0x86/0x260 mm/slab.c:3764
> putname+0xef/0x130 fs/namei.c:259
> do_sys_open+0x318/0x5d0 fs/open.c:1072
> __do_sys_open fs/open.c:1081 [inline]
> __se_sys_open fs/open.c:1076 [inline]
> __x64_sys_open+0x7e/0xc0 fs/open.c:1076
> do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
> entry_SYSCALL_64_after_hwframe+0x49/0xbe
>
> The buggy address belongs to the object at ffff88808a28c780
> which belongs to the cache names_cache of size 4096
> The buggy address is located 1364 bytes inside of
> 4096-byte region [ffff88808a28c780, ffff88808a28d780)
> The buggy address belongs to the page:
> page:ffffea000228a300 count:1 mapcount:0 mapping:ffff88812c2d8dc0 index:0x0
> compound_mapcount: 0
> flags: 0x1fffc0000010200(slab|head)
> raw: 01fffc0000010200 ffffea00025c8908 ffffea0001840a08 ffff88812c2d8dc0
> raw: 0000000000000000 ffff88808a28c780 0000000100000001 0000000000000000
> page dumped because: kasan: bad access detected
>
> Memory state around the buggy address:
> ffff88808a28cb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff88808a28cc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > ffff88808a28cc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ^
> ffff88808a28cd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff88808a28cd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==================================================================
>
>
> ---
> 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 [email protected].
>
> syzbot will keep track of this bug report. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
>
> --
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On Wed, Mar 27, 2019 at 1:22 AM Dmitry Vyukov <[email protected]> wrote:
>
> On Wed, Mar 27, 2019 at 9:19 AM syzbot
> <[email protected]> wrote:
> >
> > Hello,
> >
> > syzbot found the following crash on:
> >
> > HEAD commit: 1d965c4d Merge branch 'Refactor-flower-classifier-to-remov..
> > git tree: net-next
> > console output: https://syzkaller.appspot.com/x/log.txt?x=14ff71df200000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=f05902bca21d8935
> > dashboard link: https://syzkaller.appspot.com/bug?extid=aa9105f99c12b6abfe27
> > compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> >
> > 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: [email protected]
>
> Eric, do you think this is also fixed by "tun: properly test for
> IFF_UP" as the bug in icmp6_send?
Very possibly.
>
> > ==================================================================
> > BUG: KASAN: use-after-free in atomic_read
> > include/asm-generic/atomic-instrumented.h:26 [inline]
> > BUG: KASAN: use-after-free in queued_spin_trylock
> > include/asm-generic/qspinlock.h:69 [inline]
> > BUG: KASAN: use-after-free in do_raw_spin_trylock+0x6a/0x180
> > kernel/locking/spinlock_debug.c:119
> > Read of size 4 at addr ffff88808a28ccd4 by task syz-executor.0/17585
> >
> > CPU: 0 PID: 17585 Comm: syz-executor.0 Not tainted 5.0.0+ #105
> > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> > Google 01/01/2011
> > Call Trace:
> > <IRQ>
> > __dump_stack lib/dump_stack.c:77 [inline]
> > dump_stack+0x172/0x1f0 lib/dump_stack.c:113
> > print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
> > kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
> > check_memory_region_inline mm/kasan/generic.c:185 [inline]
> > check_memory_region+0x123/0x190 mm/kasan/generic.c:191
> > kasan_check_read+0x11/0x20 mm/kasan/common.c:102
> > atomic_read include/asm-generic/atomic-instrumented.h:26 [inline]
> > queued_spin_trylock include/asm-generic/qspinlock.h:69 [inline]
> > do_raw_spin_trylock+0x6a/0x180 kernel/locking/spinlock_debug.c:119
> > __raw_spin_trylock include/linux/spinlock_api_smp.h:89 [inline]
> > _raw_spin_trylock+0x1c/0x80 kernel/locking/spinlock.c:128
> > spin_trylock include/linux/spinlock.h:339 [inline]
> > icmp_xmit_lock net/ipv4/icmp.c:219 [inline]
> > __icmp_send+0x553/0x1400 net/ipv4/icmp.c:666
> > icmp_send include/net/icmp.h:47 [inline]
> > ipv4_link_failure+0x31/0x210 net/ipv4/route.c:1190
> > dst_link_failure include/net/dst.h:416 [inline]
> > arp_error_report+0xd1/0x1c0 net/ipv4/arp.c:297
> > neigh_invalidate+0x24b/0x570 net/core/neighbour.c:995
> > neigh_timer_handler+0xc35/0xf30 net/core/neighbour.c:1081
> > call_timer_fn+0x190/0x720 kernel/time/timer.c:1325
> > expire_timers kernel/time/timer.c:1362 [inline]
> > __run_timers kernel/time/timer.c:1681 [inline]
> > __run_timers kernel/time/timer.c:1649 [inline]
> > run_timer_softirq+0x652/0x1700 kernel/time/timer.c:1694
> > __do_softirq+0x266/0x95a kernel/softirq.c:293
> > invoke_softirq kernel/softirq.c:374 [inline]
> > irq_exit+0x180/0x1d0 kernel/softirq.c:414
> > exiting_irq arch/x86/include/asm/apic.h:536 [inline]
> > smp_apic_timer_interrupt+0x14a/0x570 arch/x86/kernel/apic/apic.c:1062
> > apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
> > </IRQ>
> > RIP: 0010:filename_mountpoint+0x25d/0x3c0 fs/namei.c:2722
> > Code: 14 02 4c 89 e0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 1c 01 00 00
> > 45 8b 24 24 31 ff 44 89 e6 e8 58 ea ba ff 45 85 e4 74 62 <e8> ce e8 ba ff
> > e8 49 2a fe ff 4c 89 f7 e8 81 f2 ff ff e8 bc e8 ba
> > RSP: 0018:ffff8880a857fc30 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
> > RAX: dffffc0000000000 RBX: 1ffff110150aff88 RCX: ffffffff81b57ad4
> > RDX: 1ffff1100bd8e54c RSI: ffffffff81b57ae2 RDI: ffff88805ec72a60
> > RBP: ffff8880a857fdc8 R08: ffff88805ec72300 R09: 0000000000000001
> > R10: 000000000000001c R11: ffff8880ae82de3b R12: 0000000000000000
> > R13: 0000000000000000 R14: ffff888097790e00 R15: ffff8880a857fe68
> > user_path_mountpoint_at+0x3a/0x50 fs/namei.c:2745
> > ksys_umount+0x167/0xf00 fs/namespace.c:1687
> > __do_sys_umount fs/namespace.c:1713 [inline]
> > __se_sys_umount fs/namespace.c:1711 [inline]
> > __x64_sys_umount+0x54/0x80 fs/namespace.c:1711
> > do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
> > entry_SYSCALL_64_after_hwframe+0x49/0xbe
> > RIP: 0033:0x45ac57
> > Code: 44 00 00 b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 4d 8e fb ff c3
> > 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff
> > ff 0f 83 2d 8e fb ff c3 66 2e 0f 1f 84 00 00 00 00
> > RSP: 002b:00007ffe6359ff08 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
> > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000045ac57
> > RDX: 0000000000402ea0 RSI: 0000000000000002 RDI: 00007ffe6359ffb0
> > RBP: 00000000000019e0 R08: 0000000000000000 R09: 000000000000000d
> > R10: 0000000000000006 R11: 0000000000000202 R12: 00007ffe635a1040
> > R13: 0000000000bfa940 R14: 0000000000000000 R15: 00007ffe635a1040
> >
> > Allocated by task 12478:
> > save_stack+0x45/0xd0 mm/kasan/common.c:75
> > set_track mm/kasan/common.c:87 [inline]
> > __kasan_kmalloc mm/kasan/common.c:497 [inline]
> > __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:470
> > kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:505
> > slab_post_alloc_hook mm/slab.h:436 [inline]
> > slab_alloc mm/slab.c:3392 [inline]
> > kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3554
> > getname_flags fs/namei.c:138 [inline]
> > getname_flags+0xd6/0x5b0 fs/namei.c:128
> > getname+0x1a/0x20 fs/namei.c:209
> > do_sys_open+0x2c9/0x5d0 fs/open.c:1057
> > __do_sys_open fs/open.c:1081 [inline]
> > __se_sys_open fs/open.c:1076 [inline]
> > __x64_sys_open+0x7e/0xc0 fs/open.c:1076
> > do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
> > entry_SYSCALL_64_after_hwframe+0x49/0xbe
> >
> > Freed by task 12478:
> > save_stack+0x45/0xd0 mm/kasan/common.c:75
> > set_track mm/kasan/common.c:87 [inline]
> > __kasan_slab_free+0x102/0x150 mm/kasan/common.c:459
> > kasan_slab_free+0xe/0x10 mm/kasan/common.c:467
> > __cache_free mm/slab.c:3498 [inline]
> > kmem_cache_free+0x86/0x260 mm/slab.c:3764
> > putname+0xef/0x130 fs/namei.c:259
> > do_sys_open+0x318/0x5d0 fs/open.c:1072
> > __do_sys_open fs/open.c:1081 [inline]
> > __se_sys_open fs/open.c:1076 [inline]
> > __x64_sys_open+0x7e/0xc0 fs/open.c:1076
> > do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
> > entry_SYSCALL_64_after_hwframe+0x49/0xbe
> >
> > The buggy address belongs to the object at ffff88808a28c780
> > which belongs to the cache names_cache of size 4096
> > The buggy address is located 1364 bytes inside of
> > 4096-byte region [ffff88808a28c780, ffff88808a28d780)
> > The buggy address belongs to the page:
> > page:ffffea000228a300 count:1 mapcount:0 mapping:ffff88812c2d8dc0 index:0x0
> > compound_mapcount: 0
> > flags: 0x1fffc0000010200(slab|head)
> > raw: 01fffc0000010200 ffffea00025c8908 ffffea0001840a08 ffff88812c2d8dc0
> > raw: 0000000000000000 ffff88808a28c780 0000000100000001 0000000000000000
> > page dumped because: kasan: bad access detected
> >
> > Memory state around the buggy address:
> > ffff88808a28cb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > ffff88808a28cc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > > ffff88808a28cc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > ^
> > ffff88808a28cd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > ffff88808a28cd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > ==================================================================
> >
> >
> > ---
> > 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 [email protected].
> >
> > syzbot will keep track of this bug report. See:
> > https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> >
> > --
> > 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 [email protected].
> > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/0000000000004cd71f05850f17c2%40google.com.
> > For more options, visit https://groups.google.com/d/optout.
On Wed, Mar 27, 2019 at 10:20 AM Eric Dumazet <[email protected]> wrote:
>
> On Wed, Mar 27, 2019 at 1:22 AM Dmitry Vyukov <[email protected]> wrote:
> >
> > On Wed, Mar 27, 2019 at 9:19 AM syzbot
> > <[email protected]> wrote:
> > >
> > > Hello,
> > >
> > > syzbot found the following crash on:
> > >
> > > HEAD commit: 1d965c4d Merge branch 'Refactor-flower-classifier-to-remov..
> > > git tree: net-next
> > > console output: https://syzkaller.appspot.com/x/log.txt?x=14ff71df200000
> > > kernel config: https://syzkaller.appspot.com/x/.config?x=f05902bca21d8935
> > > dashboard link: https://syzkaller.appspot.com/bug?extid=aa9105f99c12b6abfe27
> > > compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> > >
> > > 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: [email protected]
> >
> > Eric, do you think this is also fixed by "tun: properly test for
> > IFF_UP" as the bug in icmp6_send?
>
> Very possibly.
I will mark it as fixed then. There does not seem to be lots of info
to debug this otherwise.
#syz fix: tun: properly test for IFF_UP
Thanks
> > > ==================================================================
> > > BUG: KASAN: use-after-free in atomic_read
> > > include/asm-generic/atomic-instrumented.h:26 [inline]
> > > BUG: KASAN: use-after-free in queued_spin_trylock
> > > include/asm-generic/qspinlock.h:69 [inline]
> > > BUG: KASAN: use-after-free in do_raw_spin_trylock+0x6a/0x180
> > > kernel/locking/spinlock_debug.c:119
> > > Read of size 4 at addr ffff88808a28ccd4 by task syz-executor.0/17585
> > >
> > > CPU: 0 PID: 17585 Comm: syz-executor.0 Not tainted 5.0.0+ #105
> > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
> > > Google 01/01/2011
> > > Call Trace:
> > > <IRQ>
> > > __dump_stack lib/dump_stack.c:77 [inline]
> > > dump_stack+0x172/0x1f0 lib/dump_stack.c:113
> > > print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
> > > kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
> > > check_memory_region_inline mm/kasan/generic.c:185 [inline]
> > > check_memory_region+0x123/0x190 mm/kasan/generic.c:191
> > > kasan_check_read+0x11/0x20 mm/kasan/common.c:102
> > > atomic_read include/asm-generic/atomic-instrumented.h:26 [inline]
> > > queued_spin_trylock include/asm-generic/qspinlock.h:69 [inline]
> > > do_raw_spin_trylock+0x6a/0x180 kernel/locking/spinlock_debug.c:119
> > > __raw_spin_trylock include/linux/spinlock_api_smp.h:89 [inline]
> > > _raw_spin_trylock+0x1c/0x80 kernel/locking/spinlock.c:128
> > > spin_trylock include/linux/spinlock.h:339 [inline]
> > > icmp_xmit_lock net/ipv4/icmp.c:219 [inline]
> > > __icmp_send+0x553/0x1400 net/ipv4/icmp.c:666
> > > icmp_send include/net/icmp.h:47 [inline]
> > > ipv4_link_failure+0x31/0x210 net/ipv4/route.c:1190
> > > dst_link_failure include/net/dst.h:416 [inline]
> > > arp_error_report+0xd1/0x1c0 net/ipv4/arp.c:297
> > > neigh_invalidate+0x24b/0x570 net/core/neighbour.c:995
> > > neigh_timer_handler+0xc35/0xf30 net/core/neighbour.c:1081
> > > call_timer_fn+0x190/0x720 kernel/time/timer.c:1325
> > > expire_timers kernel/time/timer.c:1362 [inline]
> > > __run_timers kernel/time/timer.c:1681 [inline]
> > > __run_timers kernel/time/timer.c:1649 [inline]
> > > run_timer_softirq+0x652/0x1700 kernel/time/timer.c:1694
> > > __do_softirq+0x266/0x95a kernel/softirq.c:293
> > > invoke_softirq kernel/softirq.c:374 [inline]
> > > irq_exit+0x180/0x1d0 kernel/softirq.c:414
> > > exiting_irq arch/x86/include/asm/apic.h:536 [inline]
> > > smp_apic_timer_interrupt+0x14a/0x570 arch/x86/kernel/apic/apic.c:1062
> > > apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
> > > </IRQ>
> > > RIP: 0010:filename_mountpoint+0x25d/0x3c0 fs/namei.c:2722
> > > Code: 14 02 4c 89 e0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 1c 01 00 00
> > > 45 8b 24 24 31 ff 44 89 e6 e8 58 ea ba ff 45 85 e4 74 62 <e8> ce e8 ba ff
> > > e8 49 2a fe ff 4c 89 f7 e8 81 f2 ff ff e8 bc e8 ba
> > > RSP: 0018:ffff8880a857fc30 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
> > > RAX: dffffc0000000000 RBX: 1ffff110150aff88 RCX: ffffffff81b57ad4
> > > RDX: 1ffff1100bd8e54c RSI: ffffffff81b57ae2 RDI: ffff88805ec72a60
> > > RBP: ffff8880a857fdc8 R08: ffff88805ec72300 R09: 0000000000000001
> > > R10: 000000000000001c R11: ffff8880ae82de3b R12: 0000000000000000
> > > R13: 0000000000000000 R14: ffff888097790e00 R15: ffff8880a857fe68
> > > user_path_mountpoint_at+0x3a/0x50 fs/namei.c:2745
> > > ksys_umount+0x167/0xf00 fs/namespace.c:1687
> > > __do_sys_umount fs/namespace.c:1713 [inline]
> > > __se_sys_umount fs/namespace.c:1711 [inline]
> > > __x64_sys_umount+0x54/0x80 fs/namespace.c:1711
> > > do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
> > > entry_SYSCALL_64_after_hwframe+0x49/0xbe
> > > RIP: 0033:0x45ac57
> > > Code: 44 00 00 b8 08 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 4d 8e fb ff c3
> > > 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 a6 00 00 00 0f 05 <48> 3d 01 f0 ff
> > > ff 0f 83 2d 8e fb ff c3 66 2e 0f 1f 84 00 00 00 00
> > > RSP: 002b:00007ffe6359ff08 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6
> > > RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000045ac57
> > > RDX: 0000000000402ea0 RSI: 0000000000000002 RDI: 00007ffe6359ffb0
> > > RBP: 00000000000019e0 R08: 0000000000000000 R09: 000000000000000d
> > > R10: 0000000000000006 R11: 0000000000000202 R12: 00007ffe635a1040
> > > R13: 0000000000bfa940 R14: 0000000000000000 R15: 00007ffe635a1040
> > >
> > > Allocated by task 12478:
> > > save_stack+0x45/0xd0 mm/kasan/common.c:75
> > > set_track mm/kasan/common.c:87 [inline]
> > > __kasan_kmalloc mm/kasan/common.c:497 [inline]
> > > __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:470
> > > kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:505
> > > slab_post_alloc_hook mm/slab.h:436 [inline]
> > > slab_alloc mm/slab.c:3392 [inline]
> > > kmem_cache_alloc+0x11a/0x6f0 mm/slab.c:3554
> > > getname_flags fs/namei.c:138 [inline]
> > > getname_flags+0xd6/0x5b0 fs/namei.c:128
> > > getname+0x1a/0x20 fs/namei.c:209
> > > do_sys_open+0x2c9/0x5d0 fs/open.c:1057
> > > __do_sys_open fs/open.c:1081 [inline]
> > > __se_sys_open fs/open.c:1076 [inline]
> > > __x64_sys_open+0x7e/0xc0 fs/open.c:1076
> > > do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
> > > entry_SYSCALL_64_after_hwframe+0x49/0xbe
> > >
> > > Freed by task 12478:
> > > save_stack+0x45/0xd0 mm/kasan/common.c:75
> > > set_track mm/kasan/common.c:87 [inline]
> > > __kasan_slab_free+0x102/0x150 mm/kasan/common.c:459
> > > kasan_slab_free+0xe/0x10 mm/kasan/common.c:467
> > > __cache_free mm/slab.c:3498 [inline]
> > > kmem_cache_free+0x86/0x260 mm/slab.c:3764
> > > putname+0xef/0x130 fs/namei.c:259
> > > do_sys_open+0x318/0x5d0 fs/open.c:1072
> > > __do_sys_open fs/open.c:1081 [inline]
> > > __se_sys_open fs/open.c:1076 [inline]
> > > __x64_sys_open+0x7e/0xc0 fs/open.c:1076
> > > do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
> > > entry_SYSCALL_64_after_hwframe+0x49/0xbe
> > >
> > > The buggy address belongs to the object at ffff88808a28c780
> > > which belongs to the cache names_cache of size 4096
> > > The buggy address is located 1364 bytes inside of
> > > 4096-byte region [ffff88808a28c780, ffff88808a28d780)
> > > The buggy address belongs to the page:
> > > page:ffffea000228a300 count:1 mapcount:0 mapping:ffff88812c2d8dc0 index:0x0
> > > compound_mapcount: 0
> > > flags: 0x1fffc0000010200(slab|head)
> > > raw: 01fffc0000010200 ffffea00025c8908 ffffea0001840a08 ffff88812c2d8dc0
> > > raw: 0000000000000000 ffff88808a28c780 0000000100000001 0000000000000000
> > > page dumped because: kasan: bad access detected
> > >
> > > Memory state around the buggy address:
> > > ffff88808a28cb80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > > ffff88808a28cc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > > > ffff88808a28cc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > > ^
> > > ffff88808a28cd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > > ffff88808a28cd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > > ==================================================================
> > >
> > >
> > > ---
> > > 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 [email protected].
> > >
> > > syzbot will keep track of this bug report. See:
> > > https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
> > >
> > > --
> > > 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 [email protected].
> > > To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/0000000000004cd71f05850f17c2%40google.com.
> > > For more options, visit https://groups.google.com/d/optout.