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BUG: KASAN: use-after-free in ip_icmp_error+0x52a/0x5a0 net/ipv4/ip_sockglue.c:404
Read of size 1 at addr ffff8880945b67ff by task swapper/1/0

CPU: 1 PID: 0 Comm: swapper/1 Not tainted 5.7.0-rc7-next-20200526-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+0x18f/0x20d lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd3/0x413 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 ip_icmp_error+0x52a/0x5a0 net/ipv4/ip_sockglue.c:404
 tcp_v4_err+0x99e/0x1ce0 net/ipv4/tcp_ipv4.c:576
 icmp_socket_deliver+0x1e1/0x360 net/ipv4/icmp.c:803
 icmp_unreach+0x33b/0xab0 net/ipv4/icmp.c:920
 icmp_rcv+0xee6/0x15f0 net/ipv4/icmp.c:1102
 ip_protocol_deliver_rcu+0x57/0x880 net/ipv4/ip_input.c:204
 ip_local_deliver_finish+0x220/0x360 net/ipv4/ip_input.c:231
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ip_local_deliver+0x1c8/0x4e0 net/ipv4/ip_input.c:252
 dst_input include/net/dst.h:441 [inline]
 ip_rcv_finish+0x1da/0x2f0 net/ipv4/ip_input.c:428
 NF_HOOK include/linux/netfilter.h:307 [inline]
 NF_HOOK include/linux/netfilter.h:301 [inline]
 ip_rcv+0xd0/0x3c0 net/ipv4/ip_input.c:539
 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5268
 __netif_receive_skb+0x27/0x1c0 net/core/dev.c:5382
 process_backlog+0x21e/0x7a0 net/core/dev.c:6214
 napi_poll net/core/dev.c:6659 [inline]
 net_rx_action+0x4e1/0x10d0 net/core/dev.c:6727
 __do_softirq+0x268/0x9ee kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x192/0x1d0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:546 [inline]
 smp_apic_timer_interrupt+0x19e/0x600 arch/x86/kernel/apic/apic.c:1107
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:1030
 </IRQ>
RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61
Code: cc cc cc cc cc cc cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d 44 b9 4a 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d 34 b9 4a 00 fb f4 <c3> cc 41 56 41 55 41 54 55 53 e8 b3 eb 82 f9 e8 5e 66 fd ff 0f 1f
RSP: 0018:ffffc90000d3fc70 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
RAX: ffff8880a95f4340 RBX: 0000000000000000 RCX: 1ffffffff1519a2e
RDX: 0000000000000000 RSI: ffffffff87ddf958 RDI: ffff8880a95f4bc8
RBP: ffff8880a766b064 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: ffff8880a766b064
R13: 1ffff920001a7f99 R14: ffff8880a766b065 R15: 0000000000000001
 arch_safe_halt arch/x86/include/asm/paravirt.h:150 [inline]
 acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline]
 acpi_safe_halt+0x8d/0x110 drivers/acpi/processor_idle.c:108
 acpi_idle_do_entry+0xa9/0xe0 drivers/acpi/processor_idle.c:525
 acpi_idle_enter+0x437/0xb20 drivers/acpi/processor_idle.c:651
 cpuidle_enter_state+0xdb/0xd50 drivers/cpuidle/cpuidle.c:234
 cpuidle_enter+0x4a/0xa0 drivers/cpuidle/cpuidle.c:345
 call_cpuidle kernel/sched/idle.c:117 [inline]
 cpuidle_idle_call kernel/sched/idle.c:207 [inline]
 do_idle+0x42f/0x690 kernel/sched/idle.c:269
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:361
 start_secondary+0x2f8/0x410 arch/x86/kernel/smpboot.c:268
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242

Allocated by task 1:
 save_stack+0x1b/0x40 mm/kasan/common.c:48
 set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc mm/kasan/common.c:494 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:467
 __do_kmalloc mm/slab.c:3656 [inline]
 __kmalloc+0x161/0x7a0 mm/slab.c:3665
 kmalloc include/linux/slab.h:560 [inline]
 tomoyo_realpath_from_path+0xc2/0x620 security/tomoyo/realpath.c:254
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x214/0x400 security/tomoyo/file.c:822
 security_inode_getattr+0xeb/0x150 security/security.c:1278
 vfs_getattr+0x22/0x60 fs/stat.c:121
 vfs_statx+0x177/0x370 fs/stat.c:205
 vfs_lstat include/linux/fs.h:3320 [inline]
 __do_sys_newlstat+0x91/0x110 fs/stat.c:373
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:353
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Freed by task 1:
 save_stack+0x1b/0x40 mm/kasan/common.c:48
 set_track mm/kasan/common.c:56 [inline]
 kasan_set_free_info mm/kasan/common.c:316 [inline]
 __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:455
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x109/0x2b0 mm/slab.c:3757
 tomoyo_realpath_from_path+0x18f/0x620 security/tomoyo/realpath.c:291
 tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
 tomoyo_path_perm+0x214/0x400 security/tomoyo/file.c:822
 security_inode_getattr+0xeb/0x150 security/security.c:1278
 vfs_getattr+0x22/0x60 fs/stat.c:121
 vfs_statx+0x177/0x370 fs/stat.c:205
 vfs_lstat include/linux/fs.h:3320 [inline]
 __do_sys_newlstat+0x91/0x110 fs/stat.c:373
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:353
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

The buggy address belongs to the object at ffff8880945b6000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 2047 bytes inside of
 4096-byte region [ffff8880945b6000, ffff8880945b7000)
The buggy address belongs to the page:
page:ffffea0002516d80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 head:ffffea0002516d80 order:1 compound_mapcount:0
flags: 0xfffe0000010200(slab|head)
raw: 00fffe0000010200 ffffea0002576c88 ffffea000292ea08 ffff8880aa002000
raw: 0000000000000000 ffff8880945b6000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880945b6680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880945b6700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8880945b6780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                                ^
 ffff8880945b6800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880945b6880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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