================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x3ad2/0x5050 kernel/locking/lockdep.c:4770 Read of size 8 at addr ffff888101bf50a0 by task kworker/0:6/7392 CPU: 0 PID: 7392 Comm: kworker/0:6 Not tainted 5.12.0-rc6-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:79 [inline] dump_stack+0x10c/0x14b lib/dump_stack.c:120 print_address_description.constprop.0.cold+0x5b/0x2c6 mm/kasan/report.c:232 __kasan_report mm/kasan/report.c:399 [inline] kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:416 __lock_acquire+0x3ad2/0x5050 kernel/locking/lockdep.c:4770 lock_acquire kernel/locking/lockdep.c:5510 [inline] lock_acquire+0x212/0x850 kernel/locking/lockdep.c:5475 __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+0x39/0xf0 net/core/sock.c:3057 l2cap_sock_teardown_cb+0x83/0x3a0 net/bluetooth/l2cap_sock.c:1520 l2cap_chan_del+0x96/0x1010 net/bluetooth/l2cap_core.c:618 l2cap_chan_close+0xe2/0x9d0 net/bluetooth/l2cap_core.c:823 l2cap_chan_timeout+0x122/0x3a0 net/bluetooth/l2cap_core.c:436 process_one_work+0x84c/0x13b0 kernel/workqueue.c:2275 worker_thread+0x598/0xf80 kernel/workqueue.c:2421 kthread+0x36f/0x450 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Allocated by task 6091: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:427 [inline] ____kasan_kmalloc mm/kasan/common.c:506 [inline] __kasan_kmalloc+0x78/0x90 mm/kasan/common.c:515 kvmalloc include/linux/mm.h:785 [inline] xt_alloc_table_info+0x26/0x70 net/netfilter/x_tables.c:1178 do_replace net/ipv6/netfilter/ip6_tables.c:1141 [inline] do_ip6t_set_ctl+0x411/0xbe0 net/ipv6/netfilter/ip6_tables.c:1636 nf_setsockopt+0x6a/0xc0 net/netfilter/nf_sockopt.c:101 tcp_setsockopt+0x10d/0x1ff0 net/ipv4/tcp.c:3643 __sys_setsockopt+0x1fd/0x4e0 net/socket.c:2117 __do_sys_setsockopt net/socket.c:2128 [inline] __se_sys_setsockopt net/socket.c:2125 [inline] __x64_sys_setsockopt+0xb5/0x150 net/socket.c:2125 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 6091: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357 ____kasan_slab_free mm/kasan/common.c:360 [inline] ____kasan_slab_free mm/kasan/common.c:325 [inline] __kasan_slab_free+0xac/0xe0 mm/kasan/common.c:367 kasan_slab_free include/linux/kasan.h:199 [inline] __cache_free mm/slab.c:3440 [inline] kfree+0x10f/0x2d0 mm/slab.c:3796 __do_replace+0x5b5/0x8d0 net/ipv6/netfilter/ip6_tables.c:1103 do_replace net/ipv6/netfilter/ip6_tables.c:1156 [inline] do_ip6t_set_ctl+0x791/0xbe0 net/ipv6/netfilter/ip6_tables.c:1636 nf_setsockopt+0x6a/0xc0 net/netfilter/nf_sockopt.c:101 tcp_setsockopt+0x10d/0x1ff0 net/ipv4/tcp.c:3643 __sys_setsockopt+0x1fd/0x4e0 net/socket.c:2117 __do_sys_setsockopt net/socket.c:2128 [inline] __se_sys_setsockopt net/socket.c:2125 [inline] __x64_sys_setsockopt+0xb5/0x150 net/socket.c:2125 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff888101bf5000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 160 bytes inside of 2048-byte region [ffff888101bf5000, ffff888101bf5800) The buggy address belongs to the page: page:000000006af249cc refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x101bf5 flags: 0x17ffe0000000200(slab) raw: 017ffe0000000200 ffffea000405ce88 ffffea00049eaf48 ffff888100040800 raw: 0000000000000000 ffff888101bf5000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888101bf4f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888101bf5000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888101bf5080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888101bf5100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888101bf5180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== INFO: trying to register non-static key. the code is fine but needs lockdep annotation. turning off the locking correctness validator. CPU: 0 PID: 7392 Comm: kworker/0:6 Tainted: G B 5.12.0-rc6-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:79 [inline] dump_stack+0x10c/0x14b lib/dump_stack.c:120 assign_lock_key kernel/locking/lockdep.c:935 [inline] register_lock_class+0x111e/0x11f0 kernel/locking/lockdep.c:1247 __lock_acquire+0xfc/0x5050 kernel/locking/lockdep.c:4779 lock_acquire kernel/locking/lockdep.c:5510 [inline] lock_acquire+0x212/0x850 kernel/locking/lockdep.c:5475 __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+0x39/0xf0 net/core/sock.c:3057 l2cap_sock_teardown_cb+0x83/0x3a0 net/bluetooth/l2cap_sock.c:1520 l2cap_chan_del+0x96/0x1010 net/bluetooth/l2cap_core.c:618 l2cap_chan_close+0xe2/0x9d0 net/bluetooth/l2cap_core.c:823 l2cap_chan_timeout+0x122/0x3a0 net/bluetooth/l2cap_core.c:436 process_one_work+0x84c/0x13b0 kernel/workqueue.c:2275 worker_thread+0x598/0xf80 kernel/workqueue.c:2421 kthread+0x36f/0x450 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 BUG: kernel NULL pointer dereference, address: 0000000000000000 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0010) - not-present page PGD 122de5067 P4D 122de5067 PUD 1193d2067 PMD 0 Oops: 0010 [#1] PREEMPT SMP KASAN CPU: 0 PID: 7392 Comm: kworker/0:6 Tainted: G B 5.12.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events l2cap_chan_timeout RIP: 0010:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 0018:ffffc90004c77b88 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff888101bf5000 RCX: ffffffff86909f2c RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888101bf5000 RBP: 000000000000006f R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff8b895017 R11: 0000000000000001 R12: 0000000000000000 R13: ffff88810fbb4000 R14: ffff88810fbb4110 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881f6400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 0000000122de4002 CR4: 00000000001706f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: l2cap_sock_teardown_cb+0x316/0x3a0 net/bluetooth/l2cap_sock.c:1545 l2cap_chan_del+0x96/0x1010 net/bluetooth/l2cap_core.c:618 l2cap_chan_close+0xe2/0x9d0 net/bluetooth/l2cap_core.c:823 l2cap_chan_timeout+0x122/0x3a0 net/bluetooth/l2cap_core.c:436 process_one_work+0x84c/0x13b0 kernel/workqueue.c:2275 worker_thread+0x598/0xf80 kernel/workqueue.c:2421 kthread+0x36f/0x450 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Modules linked in: CR2: 0000000000000000 ---[ end trace 77b6ed110b3f8658 ]--- RIP: 0010:0x0 Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6. RSP: 0018:ffffc90004c77b88 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff888101bf5000 RCX: ffffffff86909f2c RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888101bf5000 RBP: 000000000000006f R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff8b895017 R11: 0000000000000001 R12: 0000000000000000 R13: ffff88810fbb4000 R14: ffff88810fbb4110 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881f6400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffffffffd6 CR3: 0000000122de4002 CR4: 00000000001706f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400