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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 ffff88809f932fff by task ksoftirqd/1/16

CPU: 1 PID: 16 Comm: ksoftirqd/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:
 __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
 run_ksoftirqd kernel/softirq.c:604 [inline]
 run_ksoftirqd+0x89/0x100 kernel/softirq.c:596
 smpboot_thread_fn+0x653/0x9e0 kernel/smpboot.c:165
 kthread+0x3b5/0x4a0 kernel/kthread.c:291
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:350

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 ffff88809f932000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 4095 bytes inside of
 4096-byte region [ffff88809f932000, ffff88809f933000)
The buggy address belongs to the page:
page:ffffea00027e4c80 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 head:ffffea00027e4c80 order:1 compound_mapcount:0
flags: 0xfffe0000010200(slab|head)
raw: 00fffe0000010200 ffffea00024f3288 ffffea0002498508 ffff8880aa002000
raw: 0000000000000000 ffff88809f932000 0000000100000001 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809f932e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88809f932f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88809f932f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                                ^
 ffff88809f933000: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88809f933080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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