KASAN: use-after-free Read in sk_psock

[upstream] KASAN: use-after-free Read in sk_psock_unlink
Status: upstream: reported on 2018/10/26 07:37
Reported-by: syzbot+3acd9f67a6a15766686e@syzkaller.appspotmail.com
First crash: 144d, last: 57d

Sample crash report:

==================================================================
BUG: KASAN: use-after-free in sk_psock_unlink+0x4d3/0x6e0 net/core/sock_map.c:993
Read of size 4 at addr ffff88808a950298 by task syz-executor1/11557

CPU: 0 PID: 11557 Comm: syz-executor1 Not tainted 5.0.0-rc2+ #35
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+0x1db/0x2d0 lib/dump_stack.c:113
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
 kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/generic_report.c:134
 sk_psock_unlink+0x4d3/0x6e0 net/core/sock_map.c:993
 tcp_bpf_remove+0xcb/0x130 net/ipv4/tcp_bpf.c:534
 tcp_bpf_close+0x1c6/0x4a0 net/ipv4/tcp_bpf.c:574
 inet_release+0x105/0x1f0 net/ipv4/af_inet.c:428
 __sock_release+0xd3/0x250 net/socket.c:579
 sock_close+0x1b/0x30 net/socket.c:1141
 __fput+0x3c5/0xb10 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x1f4/0x2b0 kernel/task_work.c:113
 get_signal+0x168d/0x19b0 kernel/signal.c:2347
 do_signal+0x91/0x1ea0 arch/x86/kernel/signal.c:816
 exit_to_usermode_loop+0x2f7/0x3b0 arch/x86/entry/common.c:162
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x696/0x800 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458099
Code: 6d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007eff72ff5c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: 0000000000280000 RBX: 0000000000000006 RCX: 0000000000458099
RDX: fffffffffffffe6e RSI: 0000000020a88f88 RDI: 0000000000000003
RBP: 000000000073bf00 R08: 0000000020e68000 R09: 0000000000000010
R10: 0000000020000000 R11: 0000000000000246 R12: 00007eff72ff66d4
R13: 00000000004c5680 R14: 00000000004d9340 R15: 00000000ffffffff

Allocated by task 11559:
 save_stack+0x45/0xd0 mm/kasan/common.c:73
 set_track mm/kasan/common.c:85 [inline]
 __kasan_kmalloc mm/kasan/common.c:496 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:504
 kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3609
 kmalloc include/linux/slab.h:545 [inline]
 kzalloc include/linux/slab.h:740 [inline]
 sock_hash_alloc net/core/sock_map.c:802 [inline]
 sock_hash_alloc+0x1e3/0x5b0 net/core/sock_map.c:786
 find_and_alloc_map kernel/bpf/syscall.c:129 [inline]
 map_create kernel/bpf/syscall.c:510 [inline]
 __do_sys_bpf+0x6df/0x4410 kernel/bpf/syscall.c:2603
 __se_sys_bpf kernel/bpf/syscall.c:2580 [inline]
 __x64_sys_bpf+0x73/0xb0 kernel/bpf/syscall.c:2580
 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 9594:
 save_stack+0x45/0xd0 mm/kasan/common.c:73
 set_track mm/kasan/common.c:85 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:466
 __cache_free mm/slab.c:3487 [inline]
 kfree+0xcf/0x230 mm/slab.c:3806
 sock_hash_free+0x3eb/0x5a0 net/core/sock_map.c:865
 bpf_map_free_deferred+0xba/0xf0 kernel/bpf/syscall.c:290
 process_one_work+0xd0c/0x1ce0 kernel/workqueue.c:2153
 worker_thread+0x143/0x14a0 kernel/workqueue.c:2296
 kthread+0x357/0x430 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

The buggy address belongs to the object at ffff88808a950280
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
 512-byte region [ffff88808a950280, ffff88808a950480)
The buggy address belongs to the page:
page:ffffea00022a5400 count:1 mapcount:0 mapping:ffff88812c3f0940 index:0xffff88808a950500
flags: 0x1fffc0000000200(slab)
raw: 01fffc0000000200 ffffea0001adc648 ffffea000178b7c8 ffff88812c3f0940
raw: ffff88808a950500 ffff88808a950000 0000000100000004 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88808a950180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88808a950200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88808a950280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88808a950300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88808a950380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

All crashes (8):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Maintainers
ci-upstream-kasan-gce-selinux-root	2019/01/20 13:41	upstream	6e693b3f	353f32ea	.config	log	report	daniel@iogearbox.net, davem@davemloft.net, john.fastabend@gmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kasan-gce-smack-root	2018/12/14 10:51	upstream	65e08c5e	fe7127be	.config	log	report	daniel@iogearbox.net, davem@davemloft.net, john.fastabend@gmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kasan-gce-smack-root	2018/12/02 04:15	upstream	4b783176	5a581673	.config	log	report	daniel@iogearbox.net, davem@davemloft.net, john.fastabend@gmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kasan-gce-selinux-root	2018/11/27 00:56	upstream	6f8b52ba	ac912200	.config	log	report	daniel@iogearbox.net, davem@davemloft.net, john.fastabend@gmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kasan-gce-root	2018/11/14 12:30	upstream	ccda4af0	5f5f6d14	.config	log	report	daniel@iogearbox.net, davem@davemloft.net, john.fastabend@gmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-kasan-gce-root	2018/11/14 07:52	upstream	ccda4af0	5f5f6d14	.config	log	report	daniel@iogearbox.net, davem@davemloft.net, john.fastabend@gmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-linux-next-kasan-gce-root	2018/10/25 20:12	linux-next	8c60c36d	a8292de9	.config	log	report	daniel@iogearbox.net, davem@davemloft.net, john.fastabend@gmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org
ci-upstream-linux-next-kasan-gce-root	2018/12/08 09:08	linux-next	74c4a24d	65ed2472	.config	log	report	daniel@iogearbox.net, davem@davemloft.net, john.fastabend@gmail.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org