================================================================== BUG: unable to handle kernel NULL pointer dereference at (null) IP: (null) PGD 1cb5c9067 P4D 1cb5c9067 PUD 1ca471067 PMD 0 Oops: 0010 [#1] SMP KASAN Dumping ftrace buffer: (ftrace buffer empty) Modules linked in: CPU: 0 PID: 3636 Comm: syzkaller687795 Not tainted 4.15.0-rc1+ #197 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801c91c42c0 task.stack: ffff8801bf000000 RIP: 0010: (null) RSP: 0018:ffff8801bf007960 EFLAGS: 00010292 RAX: ffff8801cabcfd80 RBX: 1ffff10037e00f2d RCX: ffffffff823a6c31 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff8801bf007968 RBP: ffff8801bf007b00 R08: 0000000000000000 R09: ffff8801c91f2c90 R10: 0000000000000008 R11: ffffed003923e599 R12: dffffc0000000000 R13: ffff8801cabcfda8 R14: ffff8801c9351400 R15: ffff8801c91f2c80 FS: 00007f7ab2d65700(0000) GS:ffff8801db400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 00000001ccbe8000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: 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: 0033:0x446439 RSP: 002b:00007f7ab2d64d08 EFLAGS: 00000246 ORIG_RAX: 000000000000002f RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446439 RDX: 0000000000000040 RSI: 00000000207e0000 RDI: 0000000000000004 RBP: 0000000000000000 R08: 00007f7ab2d65700 R09: 00007f7ab2d65700 R10: 00007f7ab2d65700 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc4419186f R14: 00007f7ab2d659c0 R15: 0000000000000000 Code: Bad RIP value. RIP: (null) RSP: ffff8801bf007960 CR2: 0000000000000000 ---[ end trace 1d6cf58a48d5320c ]--- Kernel panic - not syncing: Fatal exception BUG: KASAN: use-after-free in skcipher_request_set_tfm include/crypto/skcipher.h:499 [inline] BUG: KASAN: use-after-free in crypto_aead_copy_sgl crypto/algif_aead.c:85 [inline] BUG: KASAN: use-after-free in _aead_recvmsg crypto/algif_aead.c:210 [inline] BUG: KASAN: use-after-free in aead_recvmsg+0x1552/0x1970 crypto/algif_aead.c:313 Read of size 4 at addr ffff8801cabcfd9c by task syzkaller687795/3634 CPU: 1 PID: 3634 Comm: syzkaller687795 Tainted: G D 4.15.0-rc1+ #197 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 skcipher_request_set_tfm include/crypto/skcipher.h:499 [inline] crypto_aead_copy_sgl crypto/algif_aead.c:85 [inline] _aead_recvmsg crypto/algif_aead.c:210 [inline] aead_recvmsg+0x1552/0x1970 crypto/algif_aead.c:313 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: 0033:0x446439 RSP: 002b:00007f7ab2d64d08 EFLAGS: 00000246 ORIG_RAX: 000000000000002f RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000446439 RDX: 0000000000000040 RSI: 00000000207e0000 RDI: 0000000000000004 RBP: 0000000000000000 R08: 00007f7ab2d65700 R09: 00007f7ab2d65700 R10: 00007f7ab2d65700 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc4419186f R14: 00007f7ab2d659c0 R15: 0000000000000000 Allocated by task 3442: 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:3711 [inline] __kmalloc+0x162/0x760 mm/slab.c:3720 kmalloc include/linux/slab.h:504 [inline] kzalloc include/linux/slab.h:688 [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:926 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:472 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 3522: 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:3491 [inline] kfree+0xca/0x250 mm/slab.c:3806 kzfree+0x28/0x30 mm/slab_common.c:1482 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_sock_destruct+0x13c/0x220 crypto/algif_aead.c:522 __sk_destruct+0xfd/0x910 net/core/sock.c:1558 sk_destruct+0x47/0x80 net/core/sock.c:1593 __sk_free+0x57/0x230 net/core/sock.c:1601 sk_free+0x2a/0x40 net/core/sock.c:1612 sock_put include/net/sock.h:1655 [inline] af_alg_release+0x5d/0x70 crypto/af_alg.c:126 sock_release+0x8d/0x1e0 net/socket.c:596 sock_close+0x16/0x20 net/socket.c:1125 __fput+0x333/0x7f0 fs/file_table.c:210 ____fput+0x15/0x20 fs/file_table.c:244 task_work_run+0x199/0x270 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x9bb/0x1ae0 kernel/exit.c:865 do_group_exit+0x149/0x400 kernel/exit.c:968 SYSC_exit_group kernel/exit.c:979 [inline] SyS_exit_group+0x1d/0x20 kernel/exit.c:977 entry_SYSCALL_64_fastpath+0x1f/0x96 The buggy address belongs to the object at ffff8801cabcfd80 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 28 bytes inside of 128-byte region [ffff8801cabcfd80, ffff8801cabcfe00) The buggy address belongs to the page: page:ffffea00072af3c0 count:1 mapcount:0 mapping:ffff8801cabcf000 index:0x0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffff8801cabcf000 0000000000000000 0000000100000015 raw: ffffea00072a6ba0 ffffea0007291c20 ffff8801db000640 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801cabcfc80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff8801cabcfd00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8801cabcfd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8801cabcfe00: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff8801cabcfe80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ================================================================== Dumping ftrace buffer: (ftrace buffer empty) Kernel Offset: disabled Rebooting in 86400 seconds..