KASAN: use-after-free Read in __lock

KASAN: use-after-free Read in __lock_sock (2)
Status: upstream: reported on 2020/02/02 06:17
Reported-by: syzbot+b69cf7012e8ec83a07bf@syzkaller.appspotmail.com
First crash: 55d, last: 55d

similar bugs (3):
Kernel	Title	Repro	Bisected	Count	Last	Reported	Patched	Status
linux-4.19	KASAN: use-after-free Read in __lock_sock	syz	fix	2	152d	152d	1/1	fixed on 2019/12/18 04:11
upstream	KASAN: use-after-free Read in __lock_sock	syz	cause+fix	25	16d	497d	0/17	upstream: reported syz repro on 2018/11/17 07:18
linux-4.14	KASAN: use-after-free Read in __lock_sock	syz		1	16d	46d	0/1	upstream: reported syz repro on 2020/02/11 04:34

Sample crash report:

==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x34ac/0x49c0 kernel/locking/lockdep.c:3290
Read of size 8 at addr ffff8880528a4f60 by task syz-executor.3/6756

CPU: 0 PID: 6756 Comm: syz-executor.3 Not tainted 4.19.101-syzkaller #0
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+0x197/0x210 lib/dump_stack.c:118
 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report mm/kasan/report.c:412 [inline]
 kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:396
 __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433
 __lock_acquire+0x34ac/0x49c0 kernel/locking/lockdep.c:3290
 lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3903
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
 _raw_spin_lock_bh+0x33/0x50 kernel/locking/spinlock.c:168
 spin_lock_bh include/linux/spinlock.h:334 [inline]
 __lock_sock+0x16d/0x290 net/core/sock.c:2316
ipt_CLUSTERIP: unknown mode 3
 lock_sock_nested+0xfe/0x120 net/core/sock.c:2840
 lock_sock include/net/sock.h:1506 [inline]
 sctp_sock_dump+0x122/0xb20 net/sctp/diag.c:325
 sctp_for_each_transport+0x2b4/0x350 net/sctp/socket.c:5062
 sctp_diag_dump+0x33e/0x450 net/sctp/diag.c:528
ipt_CLUSTERIP: unknown mode 3
 __inet_diag_dump+0x9e/0x130 net/ipv4/inet_diag.c:1060
 inet_diag_dump+0x9b/0x110 net/ipv4/inet_diag.c:1076
 netlink_dump+0x427/0xbb0 net/netlink/af_netlink.c:2233
 __netlink_dump_start+0x50d/0x710 net/netlink/af_netlink.c:2329
 netlink_dump_start include/linux/netlink.h:213 [inline]
 inet_diag_handler_cmd+0x262/0x320 net/ipv4/inet_diag.c:1181
 __sock_diag_cmd net/core/sock_diag.c:232 [inline]
 sock_diag_rcv_msg+0x319/0x410 net/core/sock_diag.c:263
 netlink_rcv_skb+0x17d/0x460 net/netlink/af_netlink.c:2454
 sock_diag_rcv+0x2b/0x40 net/core/sock_diag.c:274
 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline]
 netlink_unicast+0x53a/0x730 net/netlink/af_netlink.c:1343
ipt_CLUSTERIP: unknown mode 3
 netlink_sendmsg+0x8ae/0xd70 net/netlink/af_netlink.c:1908
 sock_sendmsg_nosec net/socket.c:622 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:632
 sock_write_iter+0x2cb/0x400 net/socket.c:901
 call_write_iter include/linux/fs.h:1820 [inline]
 do_iter_readv_writev+0x558/0x830 fs/read_write.c:681
ipt_CLUSTERIP: unknown mode 3
 do_iter_write fs/read_write.c:960 [inline]
 do_iter_write+0x184/0x5f0 fs/read_write.c:941
 vfs_writev+0x1b3/0x2f0 fs/read_write.c:1005
[U] 
 do_writev+0x15e/0x370 fs/read_write.c:1040
 __do_sys_writev fs/read_write.c:1113 [inline]
 __se_sys_writev fs/read_write.c:1110 [inline]
 __x64_sys_writev+0x75/0xb0 fs/read_write.c:1110
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45b399
Code: ad b6 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 7b b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ff3c5745c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 00007ff3c57466d4 RCX: 000000000045b399
RDX: 0000000000000001 RSI: 0000000020000000 RDI: 0000000000000007
RBP: 000000000075c070 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000cdc R14: 00000000004c9ca0 R15: 000000000075c07c

Allocated by task 6705:
 save_stack+0x45/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc mm/kasan/kasan.c:553 [inline]
 kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:531
 kasan_slab_alloc+0xf/0x20 mm/kasan/kasan.c:490
 kmem_cache_alloc+0x12e/0x700 mm/slab.c:3559
 sk_prot_alloc+0x67/0x2e0 net/core/sock.c:1460
 sk_alloc+0x39/0xf70 net/core/sock.c:1520
 inet6_create net/ipv6/af_inet6.c:183 [inline]
 inet6_create+0x360/0xf70 net/ipv6/af_inet6.c:110
 __sock_create+0x3d8/0x730 net/socket.c:1276
 sock_create net/socket.c:1316 [inline]
 __sys_socket+0x103/0x220 net/socket.c:1346
 __do_sys_socket net/socket.c:1355 [inline]
 __se_sys_socket net/socket.c:1353 [inline]
 __x64_sys_socket+0x73/0xb0 net/socket.c:1353
 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 6755:
 save_stack+0x45/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3503 [inline]
 kmem_cache_free+0x86/0x260 mm/slab.c:3765
 sk_prot_free net/core/sock.c:1501 [inline]
 __sk_destruct+0x490/0x780 net/core/sock.c:1583
 sk_destruct+0xc8/0x100 net/core/sock.c:1598
 __sk_free+0xce/0x300 net/core/sock.c:1609
 sk_free+0x45/0x50 net/core/sock.c:1620
 sock_put include/net/sock.h:1707 [inline]
 sctp_close+0x715/0x860 net/sctp/socket.c:1572
 inet_release+0xe0/0x1f0 net/ipv4/af_inet.c:427
 inet6_release+0x53/0x80 net/ipv6/af_inet6.c:472
 __sock_release+0xce/0x2a0 net/socket.c:579
 sock_close+0x1b/0x30 net/socket.c:1140
 __fput+0x2dd/0x8b0 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 get_signal+0x1baa/0x1fc0 kernel/signal.c:2394
 do_signal+0x95/0x1960 arch/x86/kernel/signal.c:821
 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:163
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:271 [inline]
 do_syscall_64+0x53d/0x620 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8880528a4ec0
 which belongs to the cache SCTPv6(65:syz3) of size 1928
The buggy address is located 160 bytes inside of
 1928-byte region [ffff8880528a4ec0, ffff8880528a5648)
The buggy address belongs to the page:
page:ffffea00014a2900 count:1 mapcount:0 mapping:ffff888096593300 index:0x0 compound_mapcount: 0
flags: 0xfffe0000008100(slab|head)
raw: 00fffe0000008100 ffffea0002484e08 ffffea0001384388 ffff888096593300
raw: 0000000000000000 ffff8880528a4680 0000000100000003 ffff8880983be7c0
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff8880983be7c0

Memory state around the buggy address:
 ffff8880528a4e00: fb fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880528a4e80: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>ffff8880528a4f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                       ^
 ffff8880528a4f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880528a5000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (1):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	Syz repro	C repro	Maintainers
ci2-linux-4-19	2020/02/02 06:16	linux-4.19.y	32ee7492	2274ad39	.config	log	report			davem@davemloft.net, linux-kernel@vger.kernel.org, linux-sctp@vger.kernel.org, marcelo.leitner@gmail.com, netdev@vger.kernel.org, nhorman@tuxdriver.com, vyasevich@gmail.com