bisecting fixing commit since 738d2902773e30939a982c8df7a7f94293659810 building syzkaller on 25a0186eba20ef6f4f657039ff02eff52a838b1c testing commit 738d2902773e30939a982c8df7a7f94293659810 with gcc (GCC) 8.1.0 kernel signature: 0962d6f8d939f90d4a0deb7b667762ba3eb47415e2f6a7d46dfeb1f3eb359c7a run #0: crashed: KASAN: slab-out-of-bounds Read in bacpy run #1: crashed: KASAN: slab-out-of-bounds Read in bacpy run #2: crashed: KASAN: slab-out-of-bounds Read in bacpy run #3: crashed: KASAN: slab-out-of-bounds Read in bacpy run #4: crashed: KASAN: slab-out-of-bounds Read in bacpy run #5: crashed: KASAN: slab-out-of-bounds Read in bacpy run #6: crashed: KASAN: slab-out-of-bounds Read in bacpy run #7: crashed: KASAN: slab-out-of-bounds Read in bacpy run #8: crashed: KASAN: slab-out-of-bounds Read in bacpy run #9: boot failed: can't ssh into the instance testing current HEAD 90568ecf561540fa330511e21fcd823b0c3829c6 testing commit 90568ecf561540fa330511e21fcd823b0c3829c6 with gcc (GCC) 8.1.0 kernel signature: a8b750cc5154abb05d74d6890972aed0fb8cc9610a11ee3bf4cd103eb6547696 all runs: crashed: KASAN: slab-out-of-bounds Read in bacpy revisions tested: 2, total time: 29m25.11114936s (build: 13m16.95111945s, test: 15m18.436026618s) the crash still happens on HEAD commit msg: Merge tag 'kvm-5.6-2' of git://git.kernel.org/pub/scm/virt/kvm/kvm crash: KASAN: slab-out-of-bounds Read in bacpy ================================================================== BUG: KASAN: slab-out-of-bounds in memcpy include/linux/string.h:381 [inline] BUG: KASAN: slab-out-of-bounds in bacpy+0xe/0x10 include/net/bluetooth/bluetooth.h:238 Read of size 6 at addr ffff888090532e08 by task kworker/u5:0/1599 CPU: 0 PID: 1599 Comm: kworker/u5:0 Not tainted 5.5.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: hci0 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/0x32 mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:641 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x153/0x1d0 mm/kasan/generic.c:192 memcpy+0x23/0x50 mm/kasan/common.c:127 memcpy include/linux/string.h:381 [inline] bacpy+0xe/0x10 include/net/bluetooth/bluetooth.h:238 hci_extended_inquiry_result_evt net/bluetooth/hci_event.c:4281 [inline] hci_event_packet+0x40ba/0x9868 net/bluetooth/hci_event.c:5984 hci_rx_work+0x18e/0x940 net/bluetooth/hci_core.c:4557 process_one_work+0x88b/0x1680 kernel/workqueue.c:2264 worker_thread+0x85/0xb60 kernel/workqueue.c:2410 kthread+0x331/0x3f0 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Allocated by task 8686: save_stack+0x21/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc.constprop.17+0xc7/0xd0 mm/kasan/common.c:515 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:529 __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:142 __alloc_skb+0xd7/0x570 net/core/skbuff.c:210 alloc_skb include/linux/skbuff.h:1051 [inline] bt_skb_alloc include/net/bluetooth/bluetooth.h:341 [inline] vhci_get_user drivers/bluetooth/hci_vhci.c:165 [inline] vhci_write+0xa8/0x3e0 drivers/bluetooth/hci_vhci.c:285 call_write_iter include/linux/fs.h:1901 [inline] new_sync_write+0x3fd/0x7e0 fs/read_write.c:483 __vfs_write+0x94/0x110 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+0xca/0x5f0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 0: (stack is not available) The buggy address belongs to the object at ffff888090532c00 which belongs to the cache kmalloc-512 of size 512 The buggy address is located 8 bytes to the right of 512-byte region [ffff888090532c00, ffff888090532e00) The buggy address belongs to the page: page:ffffea0002414c80 refcount:1 mapcount:0 mapping:ffff8880aa400a80 index:0x0 flags: 0xfffe0000000200(slab) raw: 00fffe0000000200 ffffea0002564a88 ffffea0002959d08 ffff8880aa400a80 raw: 0000000000000000 ffff888090532000 0000000100000004 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888090532d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888090532d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff888090532e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888090532e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888090532f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ==================================================================