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BUG: KASAN: slab-out-of-bounds in __xfrm6_tunnel_alloc_spi net/ipv6/xfrm6_tunnel.c:124 [inline]
BUG: KASAN: slab-out-of-bounds in xfrm6_tunnel_alloc_spi+0x779/0x8a0 net/ipv6/xfrm6_tunnel.c:174
Read of size 4 at addr ffff88808f16d000 by task syz-executor.3/11823
CPU: 0 PID: 11823 Comm: syz-executor.3 Not tainted 5.8.0-rc5-next-20200716-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+0xae/0x497 mm/kasan/report.c:383
 __kasan_report mm/kasan/report.c:513 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:530
 __xfrm6_tunnel_alloc_spi net/ipv6/xfrm6_tunnel.c:124 [inline]
 xfrm6_tunnel_alloc_spi+0x779/0x8a0 net/ipv6/xfrm6_tunnel.c:174
 ipcomp6_tunnel_create net/ipv6/ipcomp6.c:84 [inline]
 ipcomp6_tunnel_attach net/ipv6/ipcomp6.c:124 [inline]
 ipcomp6_init_state net/ipv6/ipcomp6.c:159 [inline]
 ipcomp6_init_state+0x2af/0x700 net/ipv6/ipcomp6.c:139
 __xfrm_init_state+0x9a6/0x14b0 net/xfrm/xfrm_state.c:2498
 xfrm_init_state+0x1a/0x70 net/xfrm/xfrm_state.c:2525
 pfkey_msg2xfrm_state net/key/af_key.c:1291 [inline]
 pfkey_add+0x1a10/0x2b70 net/key/af_key.c:1508
 pfkey_process+0x66d/0x7a0 net/key/af_key.c:2834
 pfkey_sendmsg+0x42d/0x800 net/key/af_key.c:3673
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:671
 ____sys_sendmsg+0x331/0x810 net/socket.c:2362
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2416
 __sys_sendmmsg+0x195/0x480 net/socket.c:2506
 __do_sys_sendmmsg net/socket.c:2535 [inline]
 __se_sys_sendmmsg net/socket.c:2532 [inline]
 __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2532
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45c1d9
Code: Bad RIP value.
RSP: 002b:00007f1842da4c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 0000000000025a40 RCX: 000000000045c1d9
RDX: 0400000000000282 RSI: 0000000020000180 RDI: 0000000000000003
RBP: 000000000078bf48 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000078bf0c
R13: 00007fffa6846fcf R14: 00007f1842da59c0 R15: 000000000078bf0c
Allocated by task 7184:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
 slab_post_alloc_hook mm/slab.h:535 [inline]
 slab_alloc mm/slab.c:3312 [inline]
 kmem_cache_alloc+0x138/0x3a0 mm/slab.c:3482
 kmem_cache_zalloc include/linux/slab.h:656 [inline]
 __kernfs_new_node+0xd4/0x880 fs/kernfs/dir.c:627
 kernfs_new_node+0x93/0x120 fs/kernfs/dir.c:689
 __kernfs_create_file+0x51/0x350 fs/kernfs/file.c:1001
 sysfs_add_file_mode_ns+0x226/0x540 fs/sysfs/file.c:305
 create_files fs/sysfs/group.c:64 [inline]
 internal_create_group+0x328/0xb20 fs/sysfs/group.c:149
 internal_create_groups.part.0+0x90/0x140 fs/sysfs/group.c:189
 internal_create_groups fs/sysfs/group.c:185 [inline]
 sysfs_create_groups+0x25/0x50 fs/sysfs/group.c:215
 device_add_groups drivers/base/core.c:2015 [inline]
 device_add_attrs drivers/base/core.c:2163 [inline]
 device_add+0x7a5/0x1c40 drivers/base/core.c:2872
 netdev_register_kobject+0x17d/0x3b0 net/core/net-sysfs.c:1888
 register_netdevice+0xd29/0x1540 net/core/dev.c:9523
 __tun_chr_ioctl.isra.0+0x2c09/0x41b0 drivers/net/tun.c:2819
 vfs_ioctl fs/ioctl.c:48 [inline]
 ksys_ioctl+0x11a/0x180 fs/ioctl.c:753
 __do_sys_ioctl fs/ioctl.c:762 [inline]
 __se_sys_ioctl fs/ioctl.c:760 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:760
 do_syscall_64+0x60/0xe0 arch/x86/entry/common.c:384
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
The buggy address belongs to the object at ffff88808f16d040
 which belongs to the cache kernfs_node_cache of size 168
The buggy address is located 64 bytes to the left of
 168-byte region [ffff88808f16d040, ffff88808f16d0e8)
The buggy address belongs to the page:
page:00000000c1090d41 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x8f16d
flags: 0xfffe0000000200(slab)
raw: 00fffe0000000200 ffffea000274f088 ffffea00029c45c8 ffff8880aa203b00
raw: 0000000000000000 ffff88808f16d040 0000000100000011 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
 ffff88808f16cf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88808f16cf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88808f16d000: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
                   ^
 ffff88808f16d080: 00 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc
 ffff88808f16d100: fc fc fc fc fc 00 00 00 00 00 00 00 00 00 00 00
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