bisecting cause commit starting from 06a7a37be55e29961c9ba2abec4d07c8e0e21861 building syzkaller on bc15f7dbbc1c6e2042a7115b3fdacc0ada8c35e7 testing commit 06a7a37be55e29961c9ba2abec4d07c8e0e21861 with gcc (GCC) 8.4.1 20210217 kernel signature: c1a01bb8a89a1db1e66babf084771f7f9491dd15dad740d090c1360e6a072016 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: KASAN: use-after-free Read in lock_sock_nested run #5: crashed: KASAN: use-after-free Read in lock_sock_nested run #6: crashed: INFO: trying to register non-static key in l2cap_sock_teardown_cb run #7: crashed: KASAN: use-after-free Read in lock_sock_nested run #8: crashed: KASAN: use-after-free Read in lock_sock_nested run #9: crashed: KASAN: use-after-free Read in lock_sock_nested 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: WARNING: locking bug in l2cap_sock_teardown_cb run #13: crashed: KASAN: use-after-free Read in lock_sock_nested 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: WARNING: locking bug in l2cap_sock_teardown_cb run #17: crashed: KASAN: slab-out-of-bounds Read in lock_sock_nested run #18: crashed: KASAN: use-after-free Read in lock_sock_nested run #19: crashed: KASAN: use-after-free Read in lock_sock_nested testing release v5.8 testing commit bcf876870b95592b52519ed4aafcf9d95999bc9c with gcc (GCC) 8.4.1 20210217 kernel signature: bebd589cce272efea9cd0e0e9393f57f72dd7d5d639464d04e8d290694cd083c 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: 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: use-after-free Read in lock_sock_nested run #8: crashed: KASAN: use-after-free Read in lock_sock_nested run #9: crashed: KASAN: slab-out-of-bounds Read in lock_sock_nested testing release v5.7 testing commit 3d77e6a8804abcc0504c904bd6e5cdf3a5cf8162 with gcc (GCC) 8.4.1 20210217 kernel signature: 19c8147c5da3790d039e2c57f0be886403d25f13c9e42b935b3dc50477ca11e5 run #0: crashed: KASAN: use-after-free Read in lock_sock_nested run #1: crashed: KASAN: slab-out-of-bounds Read in lock_sock_nested run #2: crashed: WARNING: locking bug in l2cap_sock_teardown_cb 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: slab-out-of-bounds Read in lock_sock_nested run #7: crashed: KASAN: use-after-free Read in lock_sock_nested run #8: crashed: KASAN: use-after-free Read in lock_sock_nested run #9: crashed: KASAN: slab-out-of-bounds Read in lock_sock_nested testing release v5.6 testing commit 7111951b8d4973bda27ff663f2cf18b663d15b48 with gcc (GCC) 8.4.1 20210217 kernel signature: 2cf406f3147891051f65903f634171f0434533d5c4b73f2d3314407796dd5f8e all runs: crashed: KASAN: use-after-free Read in lock_sock_nested testing release v5.5 testing commit d5226fa6dbae0569ee43ecfc08bdcd6770fc4755 with gcc (GCC) 8.4.1 20210217 kernel signature: 5bb942a3f419cf715fb1b352ca9e73ca0c970e8d421a35fdf0cc0f198902f09e run #0: crashed: KASAN: use-after-free Read in lock_sock_nested run #1: crashed: KASAN: slab-out-of-bounds Read in lock_sock_nested run #2: crashed: KASAN: slab-out-of-bounds Read in lock_sock_nested run #3: crashed: KASAN: use-after-free Read in lock_sock_nested run #4: crashed: KASAN: use-after-free Read in lock_sock_nested run #5: crashed: WARNING: locking bug in l2cap_sock_teardown_cb 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: KASAN: use-after-free Read in lock_sock_nested run #9: crashed: INFO: trying to register non-static key in l2cap_sock_teardown_cb testing release v5.4 testing commit 219d54332a09e8d8741c1e1982f5eae56099de85 with gcc (GCC) 8.4.1 20210217 kernel signature: 2fa6b670244fbbbebbaec1ec0cbbf33c27d34dd569e3b395b5804f2b2956ee26 all runs: crashed: KASAN: use-after-free Read in lock_sock_nested testing release v5.3 testing commit 4d856f72c10ecb060868ed10ff1b1453943fc6c8 with gcc (GCC) 8.4.1 20210217 kernel signature: 3566c40e97ab84a5cb68fa392f3f2844d09e59c1fc7f994e3bb2196856f3bd99 all runs: boot failed: BUG: spinlock bad magic in nf_connlabels_get testing release v5.2 testing commit 0ecfebd2b52404ae0c54a878c872bb93363ada36 with gcc (GCC) 8.4.1 20210217 kernel signature: 9fee743c9649c7178fbedadf6f979c470644b8508a09606b53debbe9b2658146 all runs: boot failed: can't ssh into the instance testing release v5.1 testing commit e93c9c99a629c61837d5a7fc2120cd2b6c70dbdd with gcc (GCC) 8.4.1 20210217 kernel signature: 2732f4dded466d9f530cc609f17ac8694d7ecfdd0bdedbaa86ebf44b589c4dc2 all runs: boot failed: can't ssh into the instance testing release v5.0 testing commit 1c163f4c7b3f621efff9b28a47abb36f7378d783 with gcc (GCC) 8.4.1 20210217 kernel signature: 31fb3d9689fc679100fc42dd7ed57556a270365194411f598dd772235c3e5290 all runs: boot failed: can't ssh into the instance testing release v4.20 testing commit 8fe28cb58bcb235034b64cbbb7550a8a43fd88be with gcc (GCC) 8.4.1 20210217 kernel signature: b98ab94ad24d620f6eef8ae4776c7dcbe84a4195bb391e6111a7e9a82709f4d3 all runs: boot failed: can't ssh into the instance testing release v4.19 testing commit 84df9525b0c27f3ebc2ebb1864fa62a97fdedb7d with gcc (GCC) 8.4.1 20210217 kernel signature: 359d0be4600171e0e0bba392a34a961a10a7a351089e04446aa7fe9512ac6434 all runs: boot failed: can't ssh into the instance testing release v4.18 testing commit 94710cac0ef4ee177a63b5227664b38c95bbf703 with gcc (GCC) 8.4.1 20210217 kernel signature: 8e51f25c1577fd53e655edea5f80409f3cb235e5bdfa20d4d46d8cf2291655ad all runs: boot failed: can't ssh into the instance testing release v4.17 testing commit 29dcea88779c856c7dc92040a0c01233263101d4 with gcc (GCC) 8.4.1 20210217 ./security/selinux/include/classmap.h:247:2: error: #error New address family defined, please update secclass_map. testing release v4.16 testing commit 0adb32858b0bddf4ada5f364a84ed60b196dbcda with gcc (GCC) 8.4.1 20210217 ./security/selinux/include/classmap.h:247:2: error: #error New address family defined, please update secclass_map. orc_dump.c:106:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations] orc_dump.c:111:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations] elf.c:135:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations] elf.c:140:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations] testing release v4.15 testing commit d8a5b80568a9cb66810e75b182018e9edb68e8ff with gcc (GCC) 8.4.1 20210217 orc_dump.c:106:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations] orc_dump.c:111:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations] pager.c:36:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict] elf.c:135:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations] elf.c:140:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations] ./security/selinux/include/classmap.h:247:2: error: #error New address family defined, please update secclass_map. testing release v4.14 testing commit bebc6082da0a9f5d47a1ea2edc099bf671058bd4 with gcc (GCC) 8.4.1 20210217 orc_dump.c:105:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations] orc_dump.c:110:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations] pager.c:36:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict] elf.c:134:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations] elf.c:139:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations] ./security/selinux/include/classmap.h:245:2: error: #error New address family defined, please update secclass_map. testing release v4.13 testing commit 569dbb88e80deb68974ef6fdd6a13edb9d686261 with gcc (GCC) 8.4.1 20210217 pager.c:35:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict] elf.c:144:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations] elf.c:149:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations] ./security/selinux/include/classmap.h:242:2: error: #error New address family defined, please update secclass_map. testing release v4.12 testing commit 6f7da290413ba713f0cdd9ff1a2a9bb129ef4f6c with gcc (GCC) 8.4.1 20210217 pager.c:35:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict] elf.c:141:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations] elf.c:146:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations] ./security/selinux/include/classmap.h:238:2: error: #error New address family defined, please update secclass_map. testing release v4.11 testing commit a351e9b9fc24e982ec2f0e76379a49826036da12 with gcc (GCC) 7.5.0 elf.c:141:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations] elf.c:146:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations] pager.c:35:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict] testing release v4.10 testing commit c470abd4fde40ea6a0846a2beab642a578c0b8cd with gcc (GCC) 5.5.0 tools/include/linux/log2.h:19:1: error: ignoring attribute 'noreturn' because it conflicts with attribute 'const' [-Werror=attributes] elf.c:129:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations] elf.c:134:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations] pager.c:35:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict] testing release v4.9 testing commit 69973b830859bc6529a7a0468ba0d80ee5117826 with gcc (GCC) 5.5.0 tools/include/linux/log2.h:19:1: error: ignoring attribute 'noreturn' because it conflicts with attribute 'const' [-Werror=attributes] elf.c:129:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations] elf.c:134:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations] pager.c:35:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict] testing release v4.8 testing commit c8d2bc9bc39ebea8437fd974fdbc21847bb897a3 with gcc (GCC) 5.5.0 tools/include/linux/log2.h:19:1: error: ignoring attribute 'noreturn' because it conflicts with attribute 'const' [-Werror=attributes] elf.c:129:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations] elf.c:134:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations] pager.c:33:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict] testing release v4.7 testing commit 523d939ef98fd712632d93a5a2b588e477a7565e with gcc (GCC) 5.5.0 tools/include/linux/log2.h:19:1: error: ignoring attribute 'noreturn' because it conflicts with attribute 'const' [-Werror=attributes] elf.c:122:2: error: 'elf_getshnum' is deprecated [-Werror=deprecated-declarations] elf.c:127:2: error: 'elf_getshstrndx' is deprecated [-Werror=deprecated-declarations] pager.c:33:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict] testing release v4.6 testing commit 2dcd0af568b0cf583645c8a317dd12e344b1c72a with gcc (GCC) 5.5.0 tools/include/linux/log2.h:19:1: error: ignoring attribute 'noreturn' because it conflicts with attribute 'const' [-Werror=attributes] pager.c:33:12: error: passing argument 2 to 'restrict'-qualified parameter aliases with argument 4 [-Werror=restrict] revisions tested: 13, total time: 3h2m26.209497907s (build: 1h23m47.410052874s, test: 1h34m51.970714139s) the crash already happened on the oldest tested release commit msg: Linux 5.4 crash: KASAN: use-after-free Read in lock_sock_nested ================================================================== BUG: KASAN: use-after-free in __lock_acquire+0x3671/0x4370 kernel/locking/lockdep.c:3828 Read of size 8 at addr ffff8881def540a0 by task kworker/0:2/3093 CPU: 0 PID: 3093 Comm: kworker/0:2 Not tainted 5.4.0-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+0x128/0x182 lib/dump_stack.c:118 print_address_description.constprop.8.cold.10+0x9/0x317 mm/kasan/report.c:374 __kasan_report.cold.11+0x1c/0x37 mm/kasan/report.c:506 kasan_report+0xe/0x20 mm/kasan/common.c:634 __lock_acquire+0x3671/0x4370 kernel/locking/lockdep.c:3828 lock_acquire+0x19b/0x420 kernel/locking/lockdep.c:4487 __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:343 [inline] lock_sock_nested+0x35/0xf0 net/core/sock.c:2938 l2cap_sock_teardown_cb+0x7f/0x380 net/bluetooth/l2cap_sock.c:1331 l2cap_chan_del+0x9a/0x7e0 net/bluetooth/l2cap_core.c:603 l2cap_chan_close+0x34a/0x7d0 net/bluetooth/l2cap_core.c:761 l2cap_chan_timeout+0x115/0x1d0 net/bluetooth/l2cap_core.c:432 process_one_work+0x8d1/0x15c0 kernel/workqueue.c:2269 worker_thread+0x82/0xb50 kernel/workqueue.c:2415 kthread+0x31d/0x3e0 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Allocated by task 9548: save_stack+0x19/0x80 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_kmalloc mm/kasan/common.c:510 [inline] __kasan_kmalloc.constprop.13+0xc1/0xd0 mm/kasan/common.c:483 __do_kmalloc mm/slab.c:3655 [inline] __kmalloc+0x164/0x7b0 mm/slab.c:3664 kmalloc include/linux/slab.h:561 [inline] sk_prot_alloc+0x14d/0x260 net/core/sock.c:1605 sk_alloc+0x30/0xc80 net/core/sock.c:1659 l2cap_sock_alloc.constprop.8+0x23/0x1f0 net/bluetooth/l2cap_sock.c:1593 l2cap_sock_create+0xb1/0x190 net/bluetooth/l2cap_sock.c:1639 bt_sock_create+0x120/0x250 net/bluetooth/af_bluetooth.c:130 __sock_create+0x267/0x540 net/socket.c:1418 sock_create net/socket.c:1469 [inline] __sys_socket+0xd1/0x1a0 net/socket.c:1511 __do_sys_socket net/socket.c:1520 [inline] __se_sys_socket net/socket.c:1518 [inline] __x64_sys_socket+0x6a/0xb0 net/socket.c:1518 do_syscall_64+0xc6/0x5d0 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 9548: save_stack+0x19/0x80 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] kasan_set_free_info mm/kasan/common.c:332 [inline] __kasan_slab_free+0xf7/0x140 mm/kasan/common.c:471 __cache_free mm/slab.c:3425 [inline] kfree+0x107/0x2b0 mm/slab.c:3756 sk_prot_free net/core/sock.c:1642 [inline] __sk_destruct+0x451/0x600 net/core/sock.c:1726 l2cap_sock_release+0x104/0x130 net/bluetooth/l2cap_sock.c:1207 __sock_release+0xbb/0x270 net/socket.c:590 sock_close+0xf/0x20 net/socket.c:1268 __fput+0x256/0x780 fs/file_table.c:280 task_work_run+0x103/0x180 kernel/task_work.c:113 get_signal+0x16da/0x1d90 kernel/signal.c:2528 do_signal+0x81/0x13f0 arch/x86/kernel/signal.c:815 exit_to_usermode_loop+0x10f/0x2d0 arch/x86/entry/common.c:159 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] syscall_return_slowpath arch/x86/entry/common.c:274 [inline] do_syscall_64+0x4e2/0x5d0 arch/x86/entry/common.c:300 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8881def54000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 160 bytes inside of 2048-byte region [ffff8881def54000, ffff8881def54800) The buggy address belongs to the page: page:ffffea00077bd500 refcount:1 mapcount:0 mapping:ffff8881f5400e00 index:0x0 raw: 017ffe0000000200 ffffea00077c52c8 ffffea00077bc508 ffff8881f5400e00 raw: 0000000000000000 ffff8881def54000 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881def53f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8881def54000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8881def54080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881def54100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8881def54180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================