===================================================== BUG: KMSAN: use-after-free in skb_unref include/linux/skbuff.h:1011 [inline] BUG: KMSAN: use-after-free in kfree_skb+0x23c/0x4c0 net/core/skbuff.c:693 CPU: 1 PID: 21089 Comm: syz-executor.2 Not tainted 5.4.0-rc5+ #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+0x191/0x1f0 lib/dump_stack.c:113 kmsan_report+0x128/0x220 mm/kmsan/kmsan_report.c:108 __msan_warning+0x73/0xe0 mm/kmsan/kmsan_instr.c:245 skb_unref include/linux/skbuff.h:1011 [inline] kfree_skb+0x23c/0x4c0 net/core/skbuff.c:693 bcsp_close+0x127/0x1e0 drivers/bluetooth/hci_bcsp.c:748 hci_uart_tty_close+0x385/0x410 drivers/bluetooth/hci_ldisc.c:548 tty_ldisc_close drivers/tty/tty_ldisc.c:494 [inline] tty_ldisc_kill drivers/tty/tty_ldisc.c:642 [inline] tty_ldisc_release+0x5dd/0xd50 drivers/tty/tty_ldisc.c:814 tty_release_struct+0x4f/0x1d0 drivers/tty/tty_io.c:1612 tty_release+0x1be2/0x1e80 drivers/tty/tty_io.c:1785 __fput+0x4c9/0xba0 fs/file_table.c:280 ____fput+0x37/0x40 fs/file_table.c:313 task_work_run+0x22e/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop arch/x86/entry/common.c:163 [inline] prepare_exit_to_usermode+0x39d/0x4d0 arch/x86/entry/common.c:194 syscall_return_slowpath+0x90/0x610 arch/x86/entry/common.c:274 do_syscall_64+0xdc/0x160 arch/x86/entry/common.c:301 entry_SYSCALL_64_after_hwframe+0x63/0xe7 RIP: 0033:0x413ad1 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: 0000000000000009 RCX: 0000000000413ad1 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008 RBP: 0000000000000001 R08: 0000000041d44052 R09: ffffffffffffffff R10: 0000000000a6fcd0 R11: 0000000000000293 R12: 000000000075c9a0 R13: 000000000075c9a0 R14: 0000000000760898 R15: 000000000075bfd4 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:151 [inline] kmsan_internal_poison_shadow+0x60/0x120 mm/kmsan/kmsan.c:134 kmsan_slab_free+0x8d/0xf0 mm/kmsan/kmsan_hooks.c:108 slab_free_freelist_hook mm/slub.c:1473 [inline] slab_free mm/slub.c:3047 [inline] kmem_cache_free+0x2d1/0x2b70 mm/slub.c:3063 kfree_skbmem net/core/skbuff.c:644 [inline] __kfree_skb+0x1dd/0x210 net/core/skbuff.c:680 consume_skb+0x2b0/0x2e0 net/core/skbuff.c:838 skb_free_datagram+0x52/0x180 net/core/datagram.c:328 netlink_recvmsg+0xd2d/0x18e0 net/netlink/af_netlink.c:1996 sock_recvmsg_nosec net/socket.c:871 [inline] sock_recvmsg+0x3b3/0x3c0 net/socket.c:889 ___sys_recvmsg+0x461/0x11e0 net/socket.c:2480 __sys_recvmsg net/socket.c:2537 [inline] __do_sys_recvmsg net/socket.c:2547 [inline] __se_sys_recvmsg+0x2fa/0x450 net/socket.c:2544 __x64_sys_recvmsg+0x4a/0x70 net/socket.c:2544 do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 =====================================================