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BUG: KASAN: use-after-free in crypto_aead_alg include/crypto/aead.h:198 [inline]
BUG: KASAN: use-after-free in crypto_aead_encrypt include/crypto/aead.h:330 [inline]
BUG: KASAN: use-after-free in _aead_recvmsg crypto/algif_aead.c:308 [inline]
BUG: KASAN: use-after-free in aead_recvmsg+0x1758/0x1bc0 crypto/algif_aead.c:329
Read of size 4 at addr ffff8801bf05d85c by task syz-executor7/10173

CPU: 1 PID: 10173 Comm: syz-executor7 Not tainted 4.14.0-next-20171127+ #52
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:252
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report+0x25b/0x340 mm/kasan/report.c:409
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429
 crypto_aead_alg include/crypto/aead.h:198 [inline]
 crypto_aead_encrypt include/crypto/aead.h:330 [inline]
 _aead_recvmsg crypto/algif_aead.c:308 [inline]
 aead_recvmsg+0x1758/0x1bc0 crypto/algif_aead.c:329
 sock_recvmsg_nosec net/socket.c:805 [inline]
 sock_recvmsg+0xc9/0x110 net/socket.c:812
 ___sys_recvmsg+0x29b/0x630 net/socket.c:2207
 __sys_recvmsg+0xe2/0x210 net/socket.c:2252
 SYSC_recvmsg net/socket.c:2264 [inline]
 SyS_recvmsg+0x2d/0x50 net/socket.c:2259
 entry_SYSCALL_64_fastpath+0x1f/0x96
RIP: 0033:0x452879
RSP: 002b:00007ff01d36ebe8 EFLAGS: 00000212 ORIG_RAX: 000000000000002f
RAX: ffffffffffffffda RBX: 00000000007580d8 RCX: 0000000000452879
RDX: 0000000000000020 RSI: 0000000020c9c000 RDI: 0000000000000015
RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000212 R12: 0000000000000000
R13: 0000000000a6f7ff R14: 00007ff01d36f9c0 R15: 0000000000000003

Allocated by task 10168:
 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:3712 [inline]
 __kmalloc+0x162/0x760 mm/slab.c:3721
 kmalloc include/linux/slab.h:519 [inline]
 kzalloc include/linux/slab.h:703 [inline]
 crypto_create_tfm+0x82/0x2e0 crypto/api.c:455
 crypto_alloc_tfm+0x10e/0x2f0 crypto/api.c:540
 crypto_alloc_skcipher+0x2c/0x40 crypto/skcipher.c:929
 crypto_get_default_null_skcipher+0x5f/0x80 crypto/crypto_null.c:164
 crypto_get_default_null_skcipher2 include/crypto/null.h:17 [inline]
 aead_bind+0x89/0x140 crypto/algif_aead.c:488
 alg_bind+0x1ab/0x440 crypto/af_alg.c:179
 SYSC_bind+0x1b4/0x3f0 net/socket.c:1475
 SyS_bind+0x24/0x30 net/socket.c:1461
 entry_SYSCALL_64_fastpath+0x1f/0x96

Freed by task 10173:
 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
 kzfree+0x28/0x30 mm/slab_common.c:1514
 crypto_destroy_tfm+0x140/0x2e0 crypto/api.c:581
 crypto_free_skcipher include/crypto/skcipher.h:212 [inline]
 crypto_put_default_null_skcipher+0x35/0x60 crypto/crypto_null.c:185
 crypto_put_default_null_skcipher2 include/crypto/null.h:22 [inline]
 aead_exit_geniv+0x40/0x50 crypto/aead.c:328
 crypto_aead_exit_tfm+0x53/0x70 crypto/aead.c:88
 crypto_exit_ops crypto/api.c:315 [inline]
 crypto_destroy_tfm+0xb9/0x2e0 crypto/api.c:579
 crypto_free_aead include/crypto/aead.h:193 [inline]
 aead_release+0x30/0x50 crypto/algif_aead.c:505
 alg_do_release crypto/af_alg.c:119 [inline]
 alg_bind+0x27b/0x440 crypto/af_alg.c:200
 SYSC_bind+0x1b4/0x3f0 net/socket.c:1475
 SyS_bind+0x24/0x30 net/socket.c:1461
 entry_SYSCALL_64_fastpath+0x1f/0x96

The buggy address belongs to the object at ffff8801bf05d840
 which belongs to the cache kmalloc-128 of size 128
The buggy address is located 28 bytes inside of
 128-byte region [ffff8801bf05d840, ffff8801bf05d8c0)
The buggy address belongs to the page:
page:ffffea0006fc1740 count:1 mapcount:0 mapping:ffff8801bf05d000 index:0x0
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801bf05d000 0000000000000000 0000000100000015
raw: ffffea000700d3a0 ffffea0007378f20 ffff8801db000640 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801bf05d700: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8801bf05d780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8801bf05d800: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
                                                    ^
 ffff8801bf05d880: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff8801bf05d900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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