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BUG: KASAN: slab-out-of-bounds in asn1_ber_decoder+0x1436/0x1c20 lib/asn1_decoder.c:233
Read of size 1 at addr ffff8801c55b9b02 by task syz-executor1/18142

CPU: 1 PID: 18142 Comm: syz-executor1 Not tainted 4.14.0-rc5-mm1+ #20
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:16 [inline]
 dump_stack+0x194/0x257 lib/dump_stack.c:52
 print_address_description+0x73/0x250 mm/kasan/report.c:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report+0x25b/0x340 mm/kasan/report.c:409
 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:427
 asn1_ber_decoder+0x1436/0x1c20 lib/asn1_decoder.c:233
 x509_cert_parse+0x1dd/0x680 crypto/asymmetric_keys/x509_cert_parser.c:89
 x509_key_preparse+0x64/0x8b0 crypto/asymmetric_keys/x509_public_key.c:174
 asymmetric_key_preparse+0xa8/0x110 crypto/asymmetric_keys/asymmetric_type.c:386
 key_create_or_update+0x4c6/0xe20 security/keys/key.c:846
 SYSC_add_key security/keys/keyctl.c:122 [inline]
 SyS_add_key+0x18a/0x340 security/keys/keyctl.c:62
 entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x452869
RSP: 002b:00007ff75b218be8 EFLAGS: 00000212 ORIG_RAX: 00000000000000f8
RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452869
RDX: 00000000201d9000 RSI: 00000000205ceffb RDI: 0000000020825ff5
RBP: 0000000000000082 R08: ffffffffffffffff R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000212 R12: 00000000006f3d58
R13: 00000000ffffffff R14: 00007ff75b2196d4 R15: 0000000000000000

Allocated by task 18142:
 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_node mm/slab.c:3676 [inline]
 __kmalloc_node+0x47/0x70 mm/slab.c:3683
 kmalloc_node include/linux/slab.h:541 [inline]
 kvmalloc_node+0x99/0xd0 mm/util.c:397
 kvmalloc include/linux/mm.h:538 [inline]
 SYSC_add_key security/keys/keyctl.c:104 [inline]
 SyS_add_key+0x279/0x340 security/keys/keyctl.c:62
 entry_SYSCALL_64_fastpath+0x1f/0xbe

Freed by task 15715:
 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:3492 [inline]
 kfree+0xca/0x250 mm/slab.c:3807
 sctp_auth_shkey_free+0x113/0x180 net/sctp/auth.c:115
 sctp_auth_destroy_keys+0x25a/0x3d0 net/sctp/auth.c:131
 sctp_endpoint_destroy net/sctp/endpointola.c:259 [inline]
 sctp_endpoint_put+0x9f/0x280 net/sctp/endpointola.c:297
 sctp_endpoint_free+0x97/0xc0 net/sctp/endpointola.c:240
 sctp_destroy_sock+0xd6/0x4c0 net/sctp/socket.c:4493
 sk_common_release+0x6b/0x2f0 net/core/sock.c:2986
 sctp_close+0x45e/0x980 net/sctp/socket.c:1555
 inet_release+0xed/0x1c0 net/ipv4/af_inet.c:426
 sock_release+0x8d/0x1e0 net/socket.c:596
 SYSC_socketpair net/socket.c:1446 [inline]
 SyS_socketpair+0x4ae/0x640 net/socket.c:1352
 entry_SYSCALL_64_fastpath+0x1f/0xbe

The buggy address belongs to the object at ffff8801c55b9b00
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 2 bytes inside of
 32-byte region [ffff8801c55b9b00, ffff8801c55b9b20)
The buggy address belongs to the page:
page:ffffea0007156e40 count:1 mapcount:0 mapping:ffff8801c55b9000 index:0xffff8801c55b9fc1
flags: 0x200000000000100(slab)
raw: 0200000000000100 ffff8801c55b9000 ffff8801c55b9fc1 000000010000003f
raw: ffffea0007159de0 ffffea0007169aa0 ffff8801dac001c0 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801c55b9a00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801c55b9a80: 05 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc
>ffff8801c55b9b00: 02 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc
                   ^
 ffff8801c55b9b80: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8801c55b9c00: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
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