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BUG: KASAN: use-after-free in memset include/linux/string.h:365 [inline]
BUG: KASAN: use-after-free in __alloc_skb+0x37b/0x5e0 net/core/skbuff.c:238
Write of size 32 at addr ffff88815913efc0 by task udevd/9321

CPU: 1 PID: 9321 Comm: udevd Not tainted 5.5.0-rc1-syzkaller #0
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+0x197/0x210 lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374
 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506
 kasan_report+0x12/0x20 mm/kasan/common.c:639
 check_memory_region_inline mm/kasan/generic.c:185 [inline]
 check_memory_region+0x134/0x1a0 mm/kasan/generic.c:192
 memset+0x24/0x40 mm/kasan/common.c:108
 memset include/linux/string.h:365 [inline]
 __alloc_skb+0x37b/0x5e0 net/core/skbuff.c:238
 alloc_skb include/linux/skbuff.h:1049 [inline]
 igmpv3_newpack+0x1b9/0x1110 net/ipv4/igmp.c:361
 add_grhead.isra.0+0x235/0x300 net/ipv4/igmp.c:442
 add_grec+0x842/0x1230 net/ipv4/igmp.c:575
 igmpv3_send_cr net/ipv4/igmp.c:712 [inline]
 igmp_ifc_timer_expire+0x4af/0xab0 net/ipv4/igmp.c:809
 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1404
 expire_timers kernel/time/timer.c:1449 [inline]
 __run_timers kernel/time/timer.c:1773 [inline]
 __run_timers kernel/time/timer.c:1740 [inline]
 run_timer_softirq+0x6c3/0x1790 kernel/time/timer.c:1786
 __do_softirq+0x262/0x98c kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x19b/0x1e0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1137
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
RIP: 0010:compound_head include/linux/page-flags.h:177 [inline]
RIP: 0010:virt_to_head_page include/linux/mm.h:733 [inline]
RIP: 0010:virt_to_cache mm/slab.h:472 [inline]
RIP: 0010:cache_from_obj mm/slab.h:520 [inline]
RIP: 0010:cache_from_obj mm/slab.h:504 [inline]
RIP: 0010:kmem_cache_free+0x1f0/0x320 mm/slab.c:3686
Code: d7 ea 4d ff e9 0a ff ff ff 48 89 df e8 69 ad 82 ff 48 bf 00 00 00 00 00 ea ff ff 48 c1 e8 0c 48 c1 e0 06 48 01 c7 48 8b 47 08 <48> 8d 50 ff a8 01 48 0f 45 fa 48 8b 57 08 48 8d 42 ff 83 e2 01 48
RSP: 0018:ffffc900041a7d70 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: ffffea00029f9bc8 RBX: ffff8880989c2888 RCX: ffffffff81352aca
RDX: 0000000000000000 RSI: ffffffff81352ad4 RDI: ffffea0002627080
RBP: ffffc900041a7d90 R08: ffff88809860e140 R09: ffff88809860e9d0
R10: fffffbfff14f3330 R11: ffffffff8a799987 R12: ffff8880a6836a80
R13: ffff88809fae70c0 R14: 0000000000000001 R15: 0000000000000000
 ep_unregister_pollwait.isra.0+0x11b/0x3d0 fs/eventpoll.c:614
 ep_remove+0xef/0x6f0 fs/eventpoll.c:762
 __do_sys_epoll_ctl fs/eventpoll.c:2204 [inline]
 __se_sys_epoll_ctl fs/eventpoll.c:2082 [inline]
 __x64_sys_epoll_ctl+0xae2/0xe40 fs/eventpoll.c:2082
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f5e7938990a
Code: 48 8b 0d 31 85 2a 00 31 d2 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 90 90 90 90 90 90 90 90 90 49 89 ca b8 e9 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d fe 84 2a 00 31 d2 48 29 c2 64
RSP: 002b:00007ffdc77758a8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e9
RAX: ffffffffffffffda RBX: 0000000001444250 RCX: 00007f5e7938990a
RDX: 0000000000000005 RSI: 0000000000000002 RDI: 0000000000000007
RBP: 0000000000625500 R08: 00007ffdc77a4090 R09: 0000000000056ce6
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdc7775974
R13: 0000000000000000 R14: 00007ffdc7775914 R15: 0000000001444250

The buggy address belongs to the page:
page:ffffea0005644f80 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0
raw: 057ffe0000000000 ffffea0005644f88 ffffea0005644f88 0000000000000000
raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88815913ee80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88815913ef00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88815913ef80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                           ^
 ffff88815913f000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88815913f080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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