bisecting fixing commit since 574823bfab82d9d8fa47f422778043fbb4b4f50e building syzkaller on ee332608e9ebc1d77675662fd8511ff94fd49acd testing commit 574823bfab82d9d8fa47f422778043fbb4b4f50e with gcc (GCC) 8.1.0 kernel signature: da21fd57523f61226549887e00c5bcc17d995817 all runs: crashed: KASAN: slab-out-of-bounds Read in hci_event_packet testing current HEAD ae6088216ce4b99b3a4aaaccd2eb2dd40d473d42 testing commit ae6088216ce4b99b3a4aaaccd2eb2dd40d473d42 with gcc (GCC) 8.1.0 kernel signature: b5eb77994dadf5727932c45ddf17546750581d85 all runs: crashed: KASAN: slab-out-of-bounds Read in hci_event_packet revisions tested: 2, total time: 21m22.280821363s (build: 11m34.842922569s, test: 9m4.672802837s) the crash still happens on HEAD commit msg: Merge tag 'trace-v5.5-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace crash: KASAN: slab-out-of-bounds Read in hci_event_packet IPv6: ADDRCONF(NETDEV_CHANGE): veth1_to_hsr: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr_slave_1: link becomes ready IPv6: ADDRCONF(NETDEV_CHANGE): hsr0: link becomes ready 8021q: adding VLAN 0 to HW filter on device batadv0 ================================================================== BUG: KASAN: slab-out-of-bounds in hci_inquiry_result_with_rssi_evt net/bluetooth/hci_event.c:4072 [inline] BUG: KASAN: slab-out-of-bounds in hci_event_packet+0x7fcf/0x9a96 net/bluetooth/hci_event.c:5947 Read of size 1 at addr ffff8880a8723c00 by task kworker/u5:7/7803 CPU: 1 PID: 7803 Comm: kworker/u5:7 Not tainted 5.5.0-rc5-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: hci4 hci_rx_work Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x12d/0x187 lib/dump_stack.c:118 print_address_description.constprop.8.cold.10+0x9/0x31d mm/kasan/report.c:374 __kasan_report.cold.11+0x1b/0x3a mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:639 __asan_report_load1_noabort+0x14/0x20 mm/kasan/generic_report.c:132 hci_inquiry_result_with_rssi_evt net/bluetooth/hci_event.c:4072 [inline] hci_event_packet+0x7fcf/0x9a96 net/bluetooth/hci_event.c:5947 kobject: 'rfkill11' (00000000c43093e5): kobject_add_internal: parent: 'hci6', set: 'devices' hci_rx_work+0x53d/0x930 net/bluetooth/hci_core.c:4491 process_one_work+0x85b/0x1630 kernel/workqueue.c:2264 worker_thread+0x85/0xb60 kernel/workqueue.c:2410 kobject: 'rfkill11' (00000000c43093e5): kobject_uevent_env kthread+0x334/0x3f0 kernel/kthread.c:255 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Allocated by task 7799: save_stack+0x21/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc.constprop.9+0xc7/0xd0 mm/kasan/common.c:513 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:527 __do_kmalloc_node mm/slab.c:3616 [inline] __kmalloc_node_track_caller+0x4d/0x70 mm/slab.c:3630 __kmalloc_reserve.isra.46+0x2c/0xc0 net/core/skbuff.c:141 __alloc_skb+0xd7/0x570 net/core/skbuff.c:209 alloc_skb include/linux/skbuff.h:1049 [inline] bt_skb_alloc include/net/bluetooth/bluetooth.h:339 [inline] vhci_get_user drivers/bluetooth/hci_vhci.c:165 [inline] vhci_write+0xa8/0x3e0 drivers/bluetooth/hci_vhci.c:284 call_write_iter include/linux/fs.h:1902 [inline] new_sync_write+0x402/0x7e0 fs/read_write.c:483 __vfs_write+0x97/0x110 fs/read_write.c:496 vfs_write+0x18a/0x520 fs/read_write.c:558 ksys_write+0x105/0x220 fs/read_write.c:611 __do_sys_write fs/read_write.c:623 [inline] __se_sys_write fs/read_write.c:620 [inline] __x64_sys_write+0x6e/0xb0 fs/read_write.c:620 do_syscall_64+0xd0/0x600 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe kobject: 'rfkill11' (00000000c43093e5): fill_kobj_path: path = '/devices/virtual/bluetooth/hci6/rfkill11' Freed by task 6642: save_stack+0x21/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] kasan_set_free_info mm/kasan/common.c:335 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:474 kasan_slab_free+0xe/0x10 mm/kasan/common.c:483 __cache_free mm/slab.c:3426 [inline] kfree+0x108/0x2c0 mm/slab.c:3757 free_pipe_info+0x21c/0x2e0 fs/pipe.c:822 put_pipe_info+0x9b/0xb0 fs/pipe.c:694 pipe_release+0x128/0x1b0 fs/pipe.c:715 __fput+0x25d/0x780 fs/file_table.c:280 ____fput+0x9/0x10 fs/file_table.c:313 task_work_run+0x10e/0x190 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x1be/0x210 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline] syscall_return_slowpath arch/x86/entry/common.c:278 [inline] do_syscall_64+0x50b/0x600 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe kobject: 'hci7' (000000002ec84c88): kobject_add_internal: parent: 'bluetooth', set: 'devices' The buggy address belongs to the object at ffff8880a8723800 which belongs to the cache kmalloc-1k of size 1024 The buggy address is located 0 bytes to the right of 1024-byte region [ffff8880a8723800, ffff8880a8723c00) The buggy address belongs to the page: page:ffffea0002a1c8c0 refcount:1 mapcount:0 mapping:ffff8880aa800c40 index:0x0 raw: 01fffc0000000200 ffffea00025065c8 ffffea00024d0b88 ffff8880aa800c40 raw: 0000000000000000 ffff8880a8723000 0000000100000002 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8880a8723b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff8880a8723b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 kobject: 'hci8' (00000000fc18430f): kobject_add_internal: parent: 'bluetooth', set: 'devices' >ffff8880a8723c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc kobject: 'hci7' (000000002ec84c88): kobject_uevent_env ^ ffff8880a8723c80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8880a8723d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================