bisecting fixing commit since cb95712138ec5e480db5160b41172bbc6f6494cc building syzkaller on cef5ae6814696260ff58c538a1b6044af90c5979 testing commit cb95712138ec5e480db5160b41172bbc6f6494cc with gcc (GCC) 8.4.1 20210217 kernel signature: 9b18ca80919f5801857d441e22eb090b0b0b8a9a34d95381668c75c616aa0623 run #0: crashed: WARNING: locking bug in l2cap_sock_teardown_cb run #1: crashed: KASAN: use-after-free Read in lock_sock_nested run #2: crashed: KASAN: use-after-free Read in lock_sock_nested run #3: crashed: KASAN: slab-out-of-bounds Read in lock_sock_nested run #4: crashed: KASAN: use-after-free Read in lock_sock_nested run #5: crashed: KASAN: use-after-free Read in lock_sock_nested run #6: crashed: KASAN: use-after-free Read in lock_sock_nested run #7: crashed: KASAN: slab-out-of-bounds Read in lock_sock_nested run #8: crashed: KASAN: use-after-free Read in lock_sock_nested run #9: crashed: INFO: trying to register non-static key in l2cap_sock_teardown_cb run #10: crashed: KASAN: use-after-free Read in lock_sock_nested run #11: crashed: KASAN: use-after-free Read in lock_sock_nested run #12: crashed: KASAN: use-after-free Read in lock_sock_nested run #13: crashed: WARNING: locking bug in l2cap_sock_teardown_cb run #14: crashed: KASAN: use-after-free Read in lock_sock_nested run #15: crashed: KASAN: use-after-free Read in lock_sock_nested run #16: crashed: INFO: trying to register non-static key in l2cap_sock_teardown_cb run #17: crashed: KASAN: use-after-free Read in lock_sock_nested run #18: crashed: INFO: trying to register non-static key in l2cap_sock_teardown_cb run #19: crashed: KASAN: use-after-free Read in lock_sock_nested testing current HEAD c06a2ba62fc401b7aaefd23f5d0bc06d2457ccc1 testing commit c06a2ba62fc401b7aaefd23f5d0bc06d2457ccc1 with gcc (GCC) 10.2.1 20210217 kernel signature: 16bb3480f1140808373ba378311bad09dba101fbd09a5ceb870e5801274dd2c3 run #0: crashed: KASAN: use-after-free Read in lock_sock_nested run #1: crashed: KASAN: use-after-free Read in lock_sock_nested run #2: crashed: KASAN: use-after-free Read in lock_sock_nested run #3: crashed: KASAN: use-after-free Read in lock_sock_nested run #4: crashed: WARNING: locking bug in l2cap_sock_teardown_cb run #5: crashed: KASAN: use-after-free Read in lock_sock_nested run #6: crashed: KASAN: use-after-free Read in lock_sock_nested run #7: crashed: KASAN: use-after-free Read in lock_sock_nested run #8: crashed: INFO: trying to register non-static key in l2cap_sock_teardown_cb run #9: crashed: KASAN: slab-out-of-bounds Read in lock_sock_nested revisions tested: 2, total time: 21m13.660929547s (build: 12m36.618888359s, test: 7m48.524285327s) the crash still happens on HEAD commit msg: Merge tag 'docs-5.13-3' of git://git.lwn.net/linux crash: KASAN: slab-out-of-bounds Read in lock_sock_nested ================================================================== BUG: KASAN: slab-out-of-bounds in __lock_acquire+0x3ad2/0x5050 kernel/locking/lockdep.c:4772 Read of size 8 at addr ffff888110ce70a0 by task kworker/1:0/19 CPU: 1 PID: 19 Comm: kworker/1:0 Not tainted 5.13.0-rc1-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:233 __kasan_report mm/kasan/report.c:419 [inline] kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:436 __lock_acquire+0x3ad2/0x5050 kernel/locking/lockdep.c:4772 lock_acquire kernel/locking/lockdep.c:5512 [inline] lock_acquire+0x212/0x850 kernel/locking/lockdep.c:5477 __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:1528 l2cap_chan_del+0x96/0x1010 net/bluetooth/l2cap_core.c:622 l2cap_chan_close+0xe2/0x9d0 net/bluetooth/l2cap_core.c:825 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:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Allocated by task 8628: 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:428 [inline] ____kasan_kmalloc mm/kasan/common.c:507 [inline] __kasan_kmalloc+0x7a/0x90 mm/kasan/common.c:516 kasan_kmalloc include/linux/kasan.h:246 [inline] __do_kmalloc mm/slab.c:3702 [inline] __kmalloc+0x229/0x460 mm/slab.c:3711 kmalloc include/linux/slab.h:561 [inline] kzalloc include/linux/slab.h:686 [inline] tomoyo_get_name+0x1bc/0x400 security/tomoyo/memory.c:173 tomoyo_parse_name_union+0x81/0x130 security/tomoyo/util.c:260 tomoyo_update_path_acl security/tomoyo/file.c:395 [inline] tomoyo_write_file+0x35a/0x5a0 security/tomoyo/file.c:1022 tomoyo_write_domain2+0xb9/0x140 security/tomoyo/common.c:1152 tomoyo_add_entry security/tomoyo/common.c:2042 [inline] tomoyo_supervisor+0x97f/0xc00 security/tomoyo/common.c:2103 tomoyo_audit_path_log security/tomoyo/file.c:168 [inline] tomoyo_path_permission security/tomoyo/file.c:587 [inline] tomoyo_path_permission+0x23d/0x330 security/tomoyo/file.c:573 tomoyo_path_perm+0x2ed/0x340 security/tomoyo/file.c:838 tomoyo_path_symlink+0x7b/0xd0 security/tomoyo/tomoyo.c:200 security_path_symlink+0xbb/0x110 security/security.c:1163 do_symlinkat+0xe5/0x260 fs/namei.c:4197 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff888110ce7000 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 32 bytes to the right of 128-byte region [ffff888110ce7000, ffff888110ce7080) The buggy address belongs to the page: page:00000000d2ede989 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x110ce7 flags: 0x17ffe0000000200(slab|node=0|zone=2|lastcpupid=0x3fff) raw: 017ffe0000000200 ffffea00041111c8 ffffea00043c8c48 ffff888100040400 raw: 0000000000000000 ffff888110ce7000 0000000100000010 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888110ce6f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888110ce7000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888110ce7080: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888110ce7100: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888110ce7180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== INFO: trying to register non-static key. The code is fine but needs lockdep annotation, or maybe you didn't initialize this object before use? turning off the locking correctness validator. CPU: 1 PID: 19 Comm: kworker/1:0 Tainted: G B 5.13.0-rc1-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:937 [inline] register_lock_class+0x112a/0x1200 kernel/locking/lockdep.c:1249 __lock_acquire+0xfc/0x5050 kernel/locking/lockdep.c:4781 lock_acquire kernel/locking/lockdep.c:5512 [inline] lock_acquire+0x212/0x850 kernel/locking/lockdep.c:5477 __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:1528 l2cap_chan_del+0x96/0x1010 net/bluetooth/l2cap_core.c:622 l2cap_chan_close+0xe2/0x9d0 net/bluetooth/l2cap_core.c:825 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:313 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 kernel tried to execute NX-protected page - exploit attempt? (uid: 0) BUG: unable to handle page fault for address: ffff888110ce7458 #PF: supervisor instruction fetch in kernel mode #PF: error_code(0x0011) - permissions violation PGD c801067 P4D c801067 PUD 100b20063 PMD 8000000110c001e3 Oops: 0011 [#1] PREEMPT SMP KASAN CPU: 1 PID: 19 Comm: kworker/1:0 Tainted: G B 5.13.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events l2cap_chan_timeout RIP: 0010:0xffff888110ce7458 Code: 00 00 00 00 00 00 00 00 00 00 20 67 da 87 ff ff ff ff 00 02 00 00 00 00 00 00 48 74 ce 10 81 88 ff ff 48 74 ce 10 81 88 ff ff <58> 74 ce 10 81 88 ff ff 58 74 ce 10 81 88 ff ff 00 00 00 00 00 00 RSP: 0018:ffffc9000015fb88 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff888110ce7000 RCX: ffffffff8699449c RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888110ce7000 RBP: 000000000000006f R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff8b8d4057 R11: 0000000000000001 R12: 0000000000000000 R13: ffff88811f947000 R14: ffff88811f947110 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881f6500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff888110ce7458 CR3: 000000011cfc2005 CR4: 00000000001706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: Modules linked in: CR2: ffff888110ce7458 ---[ end trace c0f5efd10efaa49e ]--- RIP: 0010:0xffff888110ce7458 Code: 00 00 00 00 00 00 00 00 00 00 20 67 da 87 ff ff ff ff 00 02 00 00 00 00 00 00 48 74 ce 10 81 88 ff ff 48 74 ce 10 81 88 ff ff <58> 74 ce 10 81 88 ff ff 58 74 ce 10 81 88 ff ff 00 00 00 00 00 00 RSP: 0018:ffffc9000015fb88 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff888110ce7000 RCX: ffffffff8699449c RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888110ce7000 RBP: 000000000000006f R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff8b8d4057 R11: 0000000000000001 R12: 0000000000000000 R13: ffff88811f947000 R14: ffff88811f947110 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881f6500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff888110ce7458 CR3: 000000011cfc2005 CR4: 00000000001706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400