audit: type=1400 audit(1565473135.934:1966): avc: denied { map } for pid=26110 comm="blkid" path="/lib/x86_64-linux-gnu/libuuid.so.1.3.0" dev="sda1" ino=2819 scontext=system_u:system_r:kernel_t:s0 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 Bluetooth: hci0: command 0x1001 tx timeout Bluetooth: hci0: sending frame failed (-49) Bluetooth: hci0: command 0x1009 tx timeout ================================================================== BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] BUG: KASAN: use-after-free in refcount_read include/linux/refcount.h:43 [inline] BUG: KASAN: use-after-free in skb_unref include/linux/skbuff.h:967 [inline] BUG: KASAN: use-after-free in kfree_skb+0x38/0x390 net/core/skbuff.c:659 Read of size 4 at addr ffff88808b3419a4 by task syz-executor.1/25764 CPU: 0 PID: 25764 Comm: syz-executor.1 Not tainted 4.19.66 #40 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 print_address_description.cold+0x7c/0x20d mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report mm/kasan/report.c:412 [inline] kasan_report.cold+0x8c/0x2ba mm/kasan/report.c:396 check_memory_region_inline mm/kasan/kasan.c:260 [inline] check_memory_region+0x123/0x190 mm/kasan/kasan.c:267 kasan_check_read+0x11/0x20 mm/kasan/kasan.c:272 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] refcount_read include/linux/refcount.h:43 [inline] skb_unref include/linux/skbuff.h:967 [inline] kfree_skb+0x38/0x390 net/core/skbuff.c:659 bcsp_close+0xc7/0x130 drivers/bluetooth/hci_bcsp.c:763 hci_uart_tty_close+0x1ea/0x250 drivers/bluetooth/hci_ldisc.c:555 tty_ldisc_close.isra.0+0xaf/0xe0 drivers/tty/tty_ldisc.c:486 tty_ldisc_kill+0x4b/0xc0 drivers/tty/tty_ldisc.c:632 tty_ldisc_release+0xc6/0x280 drivers/tty/tty_ldisc.c:799 tty_release_struct+0x1b/0x50 drivers/tty/tty_io.c:1611 tty_release+0xbcb/0xe90 drivers/tty/tty_io.c:1784 __fput+0x2dd/0x8b0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x145/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x994/0x2fa0 kernel/exit.c:876 do_group_exit+0x135/0x370 kernel/exit.c:979 __do_sys_exit_group kernel/exit.c:990 [inline] __se_sys_exit_group kernel/exit.c:988 [inline] __x64_sys_exit_group+0x44/0x50 kernel/exit.c:988 do_syscall_64+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459829 Code: ff ff c3 c5 f8 77 eb 60 80 3d bc 39 39 01 01 0f 85 7f fd ff ff 48 83 f8 0c 0f 83 74 fe ff ff 48 8d 75 10 66 f7 c6 f0 0f 0f 84 <66> fd ff ff f3 0f 6f 4d 00 48 8d 74 17 f1 49 c7 c1 10 00 00 00 49 RSP: 002b:00007ffd2df6f618 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 000000000000000b RCX: 0000000000459829 RDX: 0000000000413451 RSI: 0000000000a74ef0 RDI: 0000000000000000 RBP: 00000000004bef34 R08: 000000000000000c R09: 00007ffd2df6f720 R10: 0000000001c41940 R11: 0000000000000246 R12: 000000000075bfc8 R13: 0000000000000003 R14: 0000000000000001 R15: 000000000075bfd4 Allocated by task 8267: save_stack+0x45/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc mm/kasan/kasan.c:553 [inline] kasan_kmalloc+0xce/0xf0 mm/kasan/kasan.c:531 kasan_slab_alloc+0xf/0x20 mm/kasan/kasan.c:490 kmem_cache_alloc_node+0x144/0x710 mm/slab.c:3649 __alloc_skb+0xd5/0x5f0 net/core/skbuff.c:193 alloc_skb include/linux/skbuff.h:995 [inline] bt_skb_alloc include/net/bluetooth/bluetooth.h:339 [inline] bcsp_recv+0x8c7/0x13a0 drivers/bluetooth/hci_bcsp.c:685 hci_uart_tty_receive+0x225/0x530 drivers/bluetooth/hci_ldisc.c:620 tty_ldisc_receive_buf+0x15f/0x1c0 drivers/tty/tty_buffer.c:460 tty_port_default_receive_buf+0x7d/0xb0 drivers/tty/tty_port.c:38 receive_buf drivers/tty/tty_buffer.c:476 [inline] flush_to_ldisc+0x222/0x390 drivers/tty/tty_buffer.c:528 process_one_work+0x989/0x1750 kernel/workqueue.c:2153 worker_thread+0x98/0xe40 kernel/workqueue.c:2296 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Freed by task 8267: save_stack+0x45/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3503 [inline] kmem_cache_free+0x86/0x260 mm/slab.c:3765 kfree_skbmem net/core/skbuff.c:586 [inline] kfree_skbmem+0xcb/0x150 net/core/skbuff.c:580 __kfree_skb net/core/skbuff.c:646 [inline] kfree_skb net/core/skbuff.c:663 [inline] kfree_skb+0xf0/0x390 net/core/skbuff.c:657 bcsp_recv+0x2d8/0x13a0 drivers/bluetooth/hci_bcsp.c:623 hci_uart_tty_receive+0x225/0x530 drivers/bluetooth/hci_ldisc.c:620 tty_ldisc_receive_buf+0x15f/0x1c0 drivers/tty/tty_buffer.c:460 tty_port_default_receive_buf+0x7d/0xb0 drivers/tty/tty_port.c:38 receive_buf drivers/tty/tty_buffer.c:476 [inline] flush_to_ldisc+0x222/0x390 drivers/tty/tty_buffer.c:528 process_one_work+0x989/0x1750 kernel/workqueue.c:2153 worker_thread+0x98/0xe40 kernel/workqueue.c:2296 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 The buggy address belongs to the object at ffff88808b3418c0 which belongs to the cache skbuff_head_cache of size 232 The buggy address is located 228 bytes inside of 232-byte region [ffff88808b3418c0, ffff88808b3419a8) The buggy address belongs to the page: page:ffffea00022cd040 count:1 mapcount:0 mapping:ffff88821bab29c0 index:0x0 flags: 0x1fffc0000000100(slab) raw: 01fffc0000000100 ffffea00022fc408 ffffea0002300b08 ffff88821bab29c0 raw: 0000000000000000 ffff88808b341000 000000010000000c 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88808b341880: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff88808b341900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88808b341980: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc ^ ffff88808b341a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88808b341a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ==================================================================