syzbot


KASAN: use-after-free Read in tls_sk_proto_close

Status: fixed on 2018/01/22 13:19
Subsystems: net
[Documentation on labels]
Reported-by: syzbot+904e7cd6c5c741609228@syzkaller.appspotmail.com
Fix commit: d91c3e17f75f net/tls: Only attach to sockets in ESTABLISHED state
First crash: 2299d, last: 2292d
Discussions (4)
Title Replies (including bot) Last reply
[PATCH 4.14 00/71] 4.14.16-stable review 77 (77) 2018/01/30 14:52
[PATCH v2 net 1/1] net/tls: Only attach to sockets in ESTABLISHED state 2 (2) 2018/01/17 21:06
[PATCH net 1/1] net/tls: Only attach to sockets in ESTABLISHED state 2 (2) 2018/01/16 11:10
KASAN: use-after-free Read in tls_sk_proto_close 0 (2) 2018/01/16 00:01
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream KASAN: use-after-free Read in tls_sk_proto_close (2) net C 297 2177d 2183d 5/26 fixed on 2018/05/17 10:02

Sample crash report:
TCP: request_sock_TCP: Possible SYN flooding on port 20000. Sending cookies.  Check SNMP counters.
==================================================================
BUG: KASAN: use-after-free in tls_sk_proto_close+0x7a0/0x800 net/tls/tls_main.c:229
Read of size 8 at addr ffff8801d1c99788 by task syzkaller779455/3660

CPU: 1 PID: 3660 Comm: syzkaller779455 Not tainted 4.15.0-rc8+ #263
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_load8_noabort+0x14/0x20 mm/kasan/report.c:430
 tls_sk_proto_close+0x7a0/0x800 net/tls/tls_main.c:229
 inet_release+0xed/0x1c0 net/ipv4/af_inet.c:426
 sock_release+0x8d/0x1e0 net/socket.c:602
 sock_close+0x16/0x20 net/socket.c:1131
 __fput+0x327/0x7e0 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/0x1ad0 kernel/exit.c:865
 do_group_exit+0x149/0x400 kernel/exit.c:968
 get_signal+0x73f/0x16c0 kernel/signal.c:2335
 do_signal+0x90/0x1eb0 arch/x86/kernel/signal.c:809
 exit_to_usermode_loop+0x214/0x310 arch/x86/entry/common.c:158
 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+0x9e/0xa0
RIP: 0033:0x4457a9
RSP: 002b:00007f9379be4db8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00000000006dac3c RCX: 00000000004457a9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000006dac3c
RBP: 00000000006dac38 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ffeda932daf R14: 00007f9379be59c0 R15: 0000000000000001

Allocated by task 3659:
 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
 kmem_cache_alloc_trace+0x136/0x750 mm/slab.c:3610
 kmalloc include/linux/slab.h:499 [inline]
 kzalloc include/linux/slab.h:688 [inline]
 tls_init+0x4b/0x240 net/tls/tls_main.c:458
 tcp_set_ulp+0x159/0x3e0 net/ipv4/tcp_ulp.c:127
 do_tcp_setsockopt.isra.38+0x316/0x2130 net/ipv4/tcp.c:2571
 tcp_setsockopt+0xb0/0xd0 net/ipv4/tcp.c:2874
 sock_common_setsockopt+0x95/0xd0 net/core/sock.c:2968
 SYSC_setsockopt net/socket.c:1831 [inline]
 SyS_setsockopt+0x189/0x360 net/socket.c:1810
 entry_SYSCALL_64_fastpath+0x29/0xa0

Freed by task 3660:
 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:3488 [inline]
 kfree+0xd6/0x260 mm/slab.c:3803
 tls_sk_proto_close+0x4bf/0x800 net/tls/tls_main.c:232
 inet_release+0xed/0x1c0 net/ipv4/af_inet.c:426
 sock_release+0x8d/0x1e0 net/socket.c:602
 sock_close+0x16/0x20 net/socket.c:1131
 __fput+0x327/0x7e0 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/0x1ad0 kernel/exit.c:865
 do_group_exit+0x149/0x400 kernel/exit.c:968
 get_signal+0x73f/0x16c0 kernel/signal.c:2335
 do_signal+0x90/0x1eb0 arch/x86/kernel/signal.c:809
 exit_to_usermode_loop+0x214/0x310 arch/x86/entry/common.c:158
 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+0x9e/0xa0

The buggy address belongs to the object at ffff8801d1c99700
 which belongs to the cache kmalloc-192 of size 192
The buggy address is located 136 bytes inside of
 192-byte region [ffff8801d1c99700, ffff8801d1c997c0)
The buggy address belongs to the page:
page:ffffea0007472640 count:1 mapcount:0 mapping:ffff8801d1c99000 index:0xffff8801d1c99000
flags: 0x2fffc0000000100(slab)
raw: 02fffc0000000100 ffff8801d1c99000 ffff8801d1c99000 000000010000000d
raw: ffffea0007661ae0 ffffea00075741e0 ffff8801dac00040 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801d1c99680: 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801d1c99700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8801d1c99780: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
                      ^
 ffff8801d1c99800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801d1c99880: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
==================================================================

Crashes (9):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/01/16 01:40 upstream a8750ddca918 e17f4a5d .config console log report syz C ci-upstream-kasan-gce
2018/01/16 03:18 upstream a8750ddca918 e17f4a5d .config console log report syz C ci-upstream-kasan-gce-386
2018/01/16 00:00 net-next-old 594831a8aba3 e17f4a5d .config console log report syz C ci-upstream-net-kasan-gce
2018/01/16 02:12 linux-next b625c1ff8227 e17f4a5d .config console log report syz C ci-upstream-next-kasan-gce
2018/01/16 01:58 mmots ce3c209f6733 e17f4a5d .config console log report syz C ci-upstream-mmots-kasan-gce
2018/01/17 08:22 net-next-old e02f08a07098 a46e5318 .config console log report ci-upstream-net-kasan-gce
2018/01/16 10:42 net-next-old 79d891c1bbb6 4198e588 .config console log report ci-upstream-net-kasan-gce
2018/01/15 23:27 net-next-old 594831a8aba3 e17f4a5d .config console log report ci-upstream-net-kasan-gce
2018/01/09 15:15 net-next-old f4803f1b73f8 11dc42f6 .config console log report ci-upstream-net-kasan-gce
* Struck through repros no longer work on HEAD.