bisecting fixing commit since d7e78d08fa77acdea351c8f628f49ca9a0e1029a building syzkaller on 318430cbb3b2ceefe51518ecccabbdabb32ffe3b testing commit d7e78d08fa77acdea351c8f628f49ca9a0e1029a with gcc (GCC) 8.1.0 kernel signature: 5057aef9b474dcdf69557560a4facd408fffaf0613e61e28eb5a924e79470bb9 all runs: crashed: KASAN: slab-out-of-bounds Read in hci_le_meta_evt testing current HEAD ca87c82811906f4fc5e936705564ba8176ba497f testing commit ca87c82811906f4fc5e936705564ba8176ba497f with gcc (GCC) 8.1.0 kernel signature: 15e71101337d32f53ee8d3041d64fb85b03aba2b6f6f4c80bca3725c14d0818b all runs: crashed: KASAN: slab-out-of-bounds Read in hci_le_meta_evt revisions tested: 2, total time: 23m44.137703988s (build: 17m9.95196854s, test: 5m52.360570941s) the crash still happens on HEAD commit msg: Linux 4.14.199 crash: KASAN: slab-out-of-bounds Read in hci_le_meta_evt IPv6: ADDRCONF(NETDEV_UP): batadv_slave_1: link is not ready batman_adv: batadv0: Interface activated: batadv_slave_1 IPv6: ADDRCONF(NETDEV_CHANGE): batadv_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_batadv: link becomes ready ================================================================== BUG: KASAN: slab-out-of-bounds in hci_le_direct_adv_report_evt net/bluetooth/hci_event.c:5152 [inline] BUG: KASAN: slab-out-of-bounds in hci_le_meta_evt+0x35a8/0x42c0 net/bluetooth/hci_event.c:5192 Read of size 1 at addr ffff8880a0e97c0c by task kworker/u5:7/6524 CPU: 1 PID: 6524 Comm: kworker/u5:7 Not tainted 4.14.199-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: hci3 hci_rx_work Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x14b/0x1f1 lib/dump_stack.c:58 print_address_description.cold.6+0x9/0x1ca mm/kasan/report.c:252 kasan_report_error mm/kasan/report.c:351 [inline] kasan_report.cold.7+0x11a/0x2d4 mm/kasan/report.c:409 __asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:427 hci_le_direct_adv_report_evt net/bluetooth/hci_event.c:5152 [inline] hci_le_meta_evt+0x35a8/0x42c0 net/bluetooth/hci_event.c:5192 Bluetooth: Unknown advertising packet type: 0x88 hci_event_packet+0x2ef6/0x70be net/bluetooth/hci_event.c:5423 Bluetooth: Unknown advertising packet type: 0x4e Bluetooth: Unknown advertising packet type: 0xff Bluetooth: Unknown advertising packet type: 0xff Bluetooth: Unknown advertising packet type: 0x88 hci_rx_work+0x30e/0x8d0 net/bluetooth/hci_core.c:4244 Bluetooth: Unknown advertising packet type: 0x88 process_one_work+0x74f/0x1620 kernel/workqueue.c:2116 Bluetooth: Unknown advertising packet type: 0xff worker_thread+0xcc/0xed0 kernel/workqueue.c:2250 Bluetooth: Unknown advertising packet type: 0xff kthread+0x338/0x400 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Allocated by task 7877: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59 save_stack mm/kasan/kasan.c:447 [inline] set_track mm/kasan/kasan.c:459 [inline] kasan_kmalloc.part.1+0x62/0xf0 mm/kasan/kasan.c:551 kasan_kmalloc+0xaf/0xc0 mm/kasan/kasan.c:536 __do_kmalloc_node mm/slab.c:3682 [inline] __kmalloc_node_track_caller+0x50/0x70 mm/slab.c:3696 __kmalloc_reserve.isra.7+0x2c/0xc0 net/core/skbuff.c:137 __alloc_skb+0xc1/0x540 net/core/skbuff.c:205 alloc_skb include/linux/skbuff.h:980 [inline] bt_skb_alloc include/net/bluetooth/bluetooth.h:336 [inline] vhci_get_user drivers/bluetooth/hci_vhci.c:180 [inline] vhci_write+0xa8/0x3e0 drivers/bluetooth/hci_vhci.c:299 call_write_iter include/linux/fs.h:1778 [inline] new_sync_write fs/read_write.c:469 [inline] __vfs_write+0x413/0x840 fs/read_write.c:482 vfs_write+0x150/0x4f0 fs/read_write.c:544 SYSC_write fs/read_write.c:590 [inline] SyS_write+0x100/0x250 fs/read_write.c:582 do_syscall_64+0x1c7/0x5b0 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x46/0xbb Freed by task 0: (stack is not available) The buggy address belongs to the object at ffff8880a0e97a00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 12 bytes to the right of 512-byte region [ffff8880a0e97a00, ffff8880a0e97c00) The buggy address belongs to the page: page:ffffea000283a5c0 count:1 mapcount:0 mapping:ffff8880a0e97000 index:0x0 flags: 0xfffe0000000100(slab) raw: 00fffe0000000100 ffff8880a0e97000 0000000000000000 0000000100000006 raw: ffffea000291eb60 ffffea00028363a0 ffff8880aa800940 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a0e97b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880a0e97b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff8880a0e97c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff8880a0e97c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a0e97d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== Bluetooth: hci5 command 0x0419 tx timeout Bluetooth: hci2 command 0x0419 tx timeout