A use-after-free flaw was found in nfc_llcp_find_local in net/nfc/llcp_core.c in NFC in the Linux Kernel. In this flaw a local user with special privilege may impact kernel information leak problem.

crash stack:
BUG: KASAN: slab-use-after-free in nfc_genl_llc_get_params+0x72f/0x780 net/nfc/netlink.c:1045
Read of size 8 at addr ffff888105b0e410 by task 20114

Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x72/0xa0 lib/dump_stack.c:106
print_address_description mm/kasan/report.c:319 [inline]
print_report+0xcc/0x620 mm/kasan/report.c:430
kasan_report+0xb2/0xe0 mm/kasan/report.c:536
nfc_genl_send_params net/nfc/netlink.c:999 [inline]
nfc_genl_llc_get_params+0x72f/0x780 net/nfc/netlink.c:1045
genl_family_rcv_msg_doit.isra.0+0x1ee/0x2e0 net/netlink/genetlink.c:968
genl_family_rcv_msg net/netlink/genetlink.c:1048 [inline]
genl_rcv_msg+0x503/0x7d0 net/netlink/genetlink.c:1065
netlink_rcv_skb+0x161/0x430 net/netlink/af_netlink.c:2548
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1076
netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
netlink_unicast+0x644/0x900 net/netlink/af_netlink.c:1365
netlink_sendmsg+0x934/0xe70 net/netlink/af_netlink.c:1913
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg+0x1b6/0x200 net/socket.c:747
____sys_sendmsg+0x6e9/0x890 net/socket.c:2501
___sys_sendmsg+0x110/0x1b0 net/socket.c:2555
__sys_sendmsg+0xf7/0x1d0 net/socket.c:2584
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3f/0x90 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x72/0xdc

Reference:
https://github.com/torvalds/linux/commit/6709d4b7bc2e079241fdef15d1160581c5261c10