KASAN: slab-out-of-bounds Read in lock_sock

KASAN: slab-out-of-bounds Read in lock_sock_nested
Status: upstream: reported on 2020/08/11 16:59
Reported-by: syzbot+9a0875bc1b2ca466b484@syzkaller.appspotmail.com
First crash: 105d, last: 11d

similar bugs (1):
Kernel	Title	Repro	Cause bisect	Fix bisect	Count	Last	Reported	Patched	Status
linux-4.19	KASAN: slab-out-of-bounds Read in lock_sock_nested				1	11d	11d	0/1	upstream: reported on 2020/11/12 16:53

Sample crash report:

==================================================================
BUG: KASAN: slab-out-of-bounds in __lock_acquire+0x3c85/0x5590 kernel/locking/lockdep.c:4701
Read of size 8 at addr ffff8880295aa0a0 by task kworker/1:2/3180

CPU: 1 PID: 3180 Comm: kworker/1:2 Not tainted 5.10.0-rc3-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: events l2cap_chan_timeout
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x107/0x163 lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xae/0x497 mm/kasan/report.c:385
 __kasan_report mm/kasan/report.c:545 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562
 __lock_acquire+0x3c85/0x5590 kernel/locking/lockdep.c:4701
 lock_acquire kernel/locking/lockdep.c:5436 [inline]
 lock_acquire+0x2a3/0x8c0 kernel/locking/lockdep.c:5401
 __raw_spin_lock_bh include/linux/spinlock_api_smp.h:135 [inline]
 _raw_spin_lock_bh+0x2f/0x40 kernel/locking/spinlock.c:175
 spin_lock_bh include/linux/spinlock.h:359 [inline]
 lock_sock_nested+0x3b/0x110 net/core/sock.c:3036
 l2cap_sock_teardown_cb+0xa1/0x660 net/bluetooth/l2cap_sock.c:1520
 l2cap_chan_del+0xbc/0xa80 net/bluetooth/l2cap_core.c:618
 l2cap_chan_close+0x1bc/0xaf0 net/bluetooth/l2cap_core.c:823
 l2cap_chan_timeout+0x17e/0x2f0 net/bluetooth/l2cap_core.c:436
 process_one_work+0x933/0x15a0 kernel/workqueue.c:2272
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2418
 kthread+0x3af/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Allocated by task 212:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:461
 __do_krealloc mm/slab_common.c:1076 [inline]
 krealloc+0x94/0xd0 mm/slab_common.c:1109
 nf_ct_ext_add+0x2d3/0x6b0 net/netfilter/nf_conntrack_extend.c:73
 nf_ct_ecache_ext_add include/net/netfilter/nf_conntrack_ecache.h:55 [inline]
 init_conntrack.constprop.0+0x5db/0x1150 net/netfilter/nf_conntrack_core.c:1597
 resolve_normal_ct net/netfilter/nf_conntrack_core.c:1674 [inline]
 nf_conntrack_in+0x9d2/0x1330 net/netfilter/nf_conntrack_core.c:1829
 ipv4_conntrack_local+0x11c/0x220 net/netfilter/nf_conntrack_proto.c:200
 nf_hook_entry_hookfn include/linux/netfilter.h:136 [inline]
 nf_hook_slow+0xc5/0x1e0 net/netfilter/core.c:589
 nf_hook+0x2cf/0x5a0 include/linux/netfilter.h:256
 __ip_local_out+0x26e/0x530 net/ipv4/ip_output.c:115
 ip_local_out net/ipv4/ip_output.c:124 [inline]
 __ip_queue_xmit+0x85d/0x1a00 net/ipv4/ip_output.c:532
 __tcp_transmit_skb+0x18cc/0x3760 net/ipv4/tcp_output.c:1404
 tcp_transmit_skb net/ipv4/tcp_output.c:1422 [inline]
 tcp_connect+0x322b/0x4950 net/ipv4/tcp_output.c:3849
 tcp_v4_connect+0x1522/0x1c40 net/ipv4/tcp_ipv4.c:312
 __inet_stream_connect+0x817/0xe30 net/ipv4/af_inet.c:661
 inet_stream_connect+0x53/0xa0 net/ipv4/af_inet.c:725
 rds_tcp_conn_path_connect+0x61c/0x880 net/rds/tcp_connect.c:172
 rds_connect_worker+0x1a5/0x2c0 net/rds/threads.c:176
 process_one_work+0x933/0x15a0 kernel/workqueue.c:2272
 worker_thread+0x64c/0x1120 kernel/workqueue.c:2418
 kthread+0x3af/0x4a0 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

The buggy address belongs to the object at ffff8880295aa000
 which belongs to the cache kmalloc-128 of size 128
The buggy address is located 32 bytes to the right of
 128-byte region [ffff8880295aa000, ffff8880295aa080)
The buggy address belongs to the page:
page:00000000428fe119 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x295aa
flags: 0xfff00000000200(slab)
raw: 00fff00000000200 ffffea00004d0d08 ffffea0000ca75c8 ffff888010040400
raw: 0000000000000000 ffff8880295aa000 0000000100000010 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8880295a9f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880295aa000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8880295aa080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                               ^
 ffff8880295aa100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880295aa180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

Crashes (8):
Manager	Time	Kernel	Commit	Syzkaller	Config	Log	Report	VM info	Maintainers
ci-upstream-kasan-gce-selinux-root	2020/11/12 04:31	upstream	3d5e28bf	cca87986	.config	log	report	info	davem@davemloft.net, johan.hedberg@gmail.com, kuba@kernel.org, linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org, marcel@holtmann.org, netdev@vger.kernel.org
ci-upstream-net-this-kasan-gce	2020/08/31 16:01	net	c8146fe2	d5a3ae1f	.config	log	report		davem@davemloft.net, johan.hedberg@gmail.com, kuba@kernel.org, linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org, marcel@holtmann.org, netdev@vger.kernel.org
ci-upstream-net-this-kasan-gce	2020/08/13 09:44	net	06a7a37b	bc15f7db	.config	log	report		davem@davemloft.net, johan.hedberg@gmail.com, kuba@kernel.org, linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org, marcel@holtmann.org, netdev@vger.kernel.org
ci-upstream-net-this-kasan-gce	2020/08/12 02:33	net	633f5b6b	bb3e5fe6	.config	log	report		davem@davemloft.net, johan.hedberg@gmail.com, kuba@kernel.org, linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org, marcel@holtmann.org, netdev@vger.kernel.org
ci-upstream-net-kasan-gce	2020/09/27 14:41	net-next	435be28b	5dd8aee8	.config	log	report	info	davem@davemloft.net, johan.hedberg@gmail.com, kuba@kernel.org, linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org, marcel@holtmann.org, netdev@vger.kernel.org
ci-upstream-net-kasan-gce	2020/09/11 08:09	net-next	9984c0bb	adfb8b4e	.config	log	report		davem@davemloft.net, johan.hedberg@gmail.com, kuba@kernel.org, linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org, marcel@holtmann.org, netdev@vger.kernel.org
ci-upstream-net-kasan-gce	2020/08/13 02:48	net-next	bfdd5aaa	bc15f7db	.config	log	report		davem@davemloft.net, johan.hedberg@gmail.com, kuba@kernel.org, linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org, marcel@holtmann.org, netdev@vger.kernel.org
ci-upstream-net-kasan-gce	2020/08/10 18:04	net-next	bfdd5aaa	7adc7b65	.config	log	report		davem@davemloft.net, johan.hedberg@gmail.com, kuba@kernel.org, linux-bluetooth@vger.kernel.org, linux-kernel@vger.kernel.org, marcel@holtmann.org, netdev@vger.kernel.org