================================================================== BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:26 [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:1010 [inline] BUG: KASAN: use-after-free in kfree_skb+0x38/0x3c0 net/core/skbuff.c:693 Read of size 4 at addr ffff88805bb05794 by task syz-executor.5/7200 CPU: 1 PID: 7200 Comm: syz-executor.5 Not tainted 5.4.0-rc6+ #0 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+0x197/0x210 lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:634 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x134/0x1a0 mm/kasan/generic.c:192 __kasan_check_read+0x11/0x20 mm/kasan/common.c:92 atomic_read include/asm-generic/atomic-instrumented.h:26 [inline] refcount_read include/linux/refcount.h:43 [inline] skb_unref include/linux/skbuff.h:1010 [inline] kfree_skb+0x38/0x3c0 net/core/skbuff.c:693 bcsp_close+0xc7/0x130 drivers/bluetooth/hci_bcsp.c:748 hci_uart_tty_close+0x21e/0x280 drivers/bluetooth/hci_ldisc.c:548 tty_ldisc_close.isra.0+0x119/0x1a0 drivers/tty/tty_ldisc.c:494 tty_ldisc_kill+0x9c/0x160 drivers/tty/tty_ldisc.c:642 tty_ldisc_release+0xe9/0x2b0 drivers/tty/tty_ldisc.c:814 tty_release_struct+0x1b/0x50 drivers/tty/tty_io.c:1612 tty_release+0xbcb/0xe90 drivers/tty/tty_io.c:1785 __fput+0x2ff/0x890 fs/file_table.c:280 ____fput+0x16/0x20 fs/file_table.c:313 task_work_run+0x145/0x1c0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x316/0x380 arch/x86/entry/common.c:163 prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] syscall_return_slowpath arch/x86/entry/common.c:274 [inline] do_syscall_64+0x65f/0x760 arch/x86/entry/common.c:300 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x413db1 Code: 75 14 b8 03 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff 48 89 04 24 b8 03 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 53 fc ff ff 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:0000000000a6fbf0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000413db1 RDX: 0000001b2bc20000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000001 R08: 000000003cca25f7 R09: ffffffffffffffff R10: 0000000000a6fcd0 R11: 0000000000000293 R12: 000000000075c9a0 R13: 000000000075c9a0 R14: 00000000007603a8 R15: 000000000075bf2c Allocated by task 24805: save_stack+0x23/0x90 mm/kasan/common.c:69 set_track mm/kasan/common.c:77 [inline] __kasan_kmalloc mm/kasan/common.c:510 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:483 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:518 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc_node mm/slab.c:3262 [inline] kmem_cache_alloc_node+0x138/0x740 mm/slab.c:3574 __alloc_skb+0xd5/0x5e0 net/core/skbuff.c:197 alloc_skb include/linux/skbuff.h:1049 [inline] bt_skb_alloc include/net/bluetooth/bluetooth.h:339 [inline] bcsp_recv+0x8c1/0x13a0 drivers/bluetooth/hci_bcsp.c:670 hci_uart_tty_receive+0x279/0x6e0 drivers/bluetooth/hci_ldisc.c:613 tty_ldisc_receive_buf+0x15f/0x1c0 drivers/tty/tty_buffer.c:465 tty_port_default_receive_buf+0x7d/0xb0 drivers/tty/tty_port.c:38 receive_buf drivers/tty/tty_buffer.c:481 [inline] flush_to_ldisc+0x222/0x390 drivers/tty/tty_buffer.c:533 process_one_work+0x9af/0x1740 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Freed by task 24805: save_stack+0x23/0x90 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+0x102/0x150 mm/kasan/common.c:471 kasan_slab_free+0xe/0x10 mm/kasan/common.c:480 __cache_free mm/slab.c:3425 [inline] kmem_cache_free+0x86/0x320 mm/slab.c:3693 kfree_skbmem net/core/skbuff.c:623 [inline] kfree_skbmem+0xc5/0x150 net/core/skbuff.c:617 __kfree_skb net/core/skbuff.c:680 [inline] kfree_skb net/core/skbuff.c:697 [inline] kfree_skb+0x109/0x3c0 net/core/skbuff.c:691 bcsp_recv+0x2d8/0x13a0 drivers/bluetooth/hci_bcsp.c:608 hci_uart_tty_receive+0x279/0x6e0 drivers/bluetooth/hci_ldisc.c:613 tty_ldisc_receive_buf+0x15f/0x1c0 drivers/tty/tty_buffer.c:465 tty_port_default_receive_buf+0x7d/0xb0 drivers/tty/tty_port.c:38 receive_buf drivers/tty/tty_buffer.c:481 [inline] flush_to_ldisc+0x222/0x390 drivers/tty/tty_buffer.c:533 process_one_work+0x9af/0x1740 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 The buggy address belongs to the object at ffff88805bb056c0 which belongs to the cache skbuff_head_cache of size 224 The buggy address is located 212 bytes inside of 224-byte region [ffff88805bb056c0, ffff88805bb057a0) The buggy address belongs to the page: page:ffffea00016ec140 refcount:1 mapcount:0 mapping:ffff8880a99ce8c0 index:0x0 flags: 0x1fffc0000000200(slab) raw: 01fffc0000000200 ffffea000288d608 ffffea000292d7c8 ffff8880a99ce8c0 raw: 0000000000000000 ffff88805bb05080 000000010000000c 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88805bb05680: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff88805bb05700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88805bb05780: fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88805bb05800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88805bb05880: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ==================================================================