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BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:344 [inline]
BUG: KASAN: slab-out-of-bounds in sha3_update+0xdf/0x2e0 crypto/sha3_generic.c:161
Write of size 192 at addr ffff8801d2056b7c by task syz-executor4/8381
binder: 8370 RLIMIT_NICE not set
binder: 8357:8370 transaction failed 29189/-22, size 40-0 line 2845

CPU: 1 PID: 8381 Comm: syz-executor4 Not tainted 4.15.0-rc4-mm1+ #49
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:53
 print_address_description+0x73/0x250 mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:355 [inline]
 kasan_report+0x23b/0x360 mm/kasan/report.c:413
 check_memory_region_inline mm/kasan/kasan.c:260 [inline]
 check_memory_region+0x137/0x190 mm/kasan/kasan.c:267
 memcpy+0x37/0x50 mm/kasan/kasan.c:303
 memcpy include/linux/string.h:344 [inline]
 sha3_update+0xdf/0x2e0 crypto/sha3_generic.c:161
 crypto_shash_update+0xda/0x240 crypto/shash.c:110
 hmac_update+0x7e/0xa0 crypto/hmac.c:122
 crypto_shash_update+0xda/0x240 crypto/shash.c:110
 kdf_ctr security/keys/dh.c:181 [inline]
 keyctl_dh_compute_kdf security/keys/dh.c:226 [inline]
 __keyctl_dh_compute+0x160f/0x1990 security/keys/dh.c:398
 keyctl_dh_compute+0xac/0xf3 security/keys/dh.c:434
 SYSC_keyctl security/keys/keyctl.c:1741 [inline]
 SyS_keyctl+0x72/0x2c0 security/keys/keyctl.c:1637
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452ac9
RSP: 002b:00007f6e599fbc58 EFLAGS: 00000212 ORIG_RAX: 00000000000000fa
RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452ac9
RDX: 00000000205cd000 RSI: 0000000020ab2ff4 RDI: 0000000000000017
RBP: 000000000000039b R08: 0000000020550000 R09: 0000000000000000
R10: 0000000000000030 R11: 0000000000000212 R12: 00000000006f2728
R13: 00000000ffffffff R14: 00007f6e599fc6d4 R15: 0000000000000000

Allocated by task 8381:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
 __do_kmalloc mm/slab.c:3705 [inline]
 __kmalloc+0x162/0x760 mm/slab.c:3714
 kmalloc include/linux/slab.h:521 [inline]
 kdf_alloc security/keys/dh.c:111 [inline]
 __keyctl_dh_compute+0x2b0/0x1990 security/keys/dh.c:288
 keyctl_dh_compute+0xac/0xf3 security/keys/dh.c:434
 SYSC_keyctl security/keys/keyctl.c:1741 [inline]
 SyS_keyctl+0x72/0x2c0 security/keys/keyctl.c:1637
 entry_SYSCALL_64_fastpath+0x1f/0x96

Freed by task 5135:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:447
 set_track mm/kasan/kasan.c:459 [inline]
 kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
 __cache_free mm/slab.c:3485 [inline]
 kfree+0xd6/0x260 mm/slab.c:3800
 skb_free_head+0x74/0xb0 net/core/skbuff.c:550
 skb_release_data+0x58c/0x790 net/core/skbuff.c:570
 skb_release_all+0x4a/0x60 net/core/skbuff.c:627
 __kfree_skb net/core/skbuff.c:641 [inline]
 kfree_skb+0x15d/0x4c0 net/core/skbuff.c:659
 tun_queue_purge+0x13e/0x410 drivers/net/tun.c:638
 __tun_detach+0xcad/0x1550 drivers/net/tun.c:675
 tun_detach drivers/net/tun.c:699 [inline]
 tun_chr_close+0x44/0x60 drivers/net/tun.c:2955
 __fput+0x327/0x7e0 fs/file_table.c:209
 ____fput+0x15/0x20 fs/file_table.c:243
 task_work_run+0x199/0x270 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x9bb/0x1ad0 kernel/exit.c:869
 do_group_exit+0x149/0x400 kernel/exit.c:972
 get_signal+0x73f/0x16c0 kernel/signal.c:2337
 do_signal+0x94/0x1ee0 arch/x86/kernel/signal.c:809
 exit_to_usermode_loop+0x258/0x2f0 arch/x86/entry/common.c:161
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath+0x490/0x550 arch/x86/entry/common.c:264
 entry_SYSCALL_64_fastpath+0x94/0x96

The buggy address belongs to the object at ffff8801d2056a80
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 252 bytes inside of
 512-byte region [ffff8801d2056a80, ffff8801d2056c80)
The buggy address belongs to the page:
page:ffffea0007481580 count:1 mapcount:0 mapping:ffff8801d2056080 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801d2056080 0000000000000000 0000000100000006
raw: ffffea0007377de0 ffffea0007355be0 ffff8801dac00940 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d2056b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8801d2056b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8801d2056c00: 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                      ^
 ffff8801d2056c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801d2056d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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