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BUG: KMSAN: uninit-value in packet_rcv_fanout+0x2442/0x25c0 net/packet/af_packet.c:1463
CPU: 1 PID: 13752 Comm: syz-executor.1 Not tainted 5.8.0-rc5-syzkaller #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+0x1df/0x240 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215
 packet_rcv_fanout+0x2442/0x25c0 net/packet/af_packet.c:1463
 deliver_skb net/core/dev.c:2247 [inline]
 dev_queue_xmit_nit+0x862/0x1280 net/core/dev.c:2317
 xmit_one net/core/dev.c:3552 [inline]
 dev_hard_start_xmit+0x20c/0xa70 net/core/dev.c:3572
 __dev_queue_xmit+0x2f8d/0x3b20 net/core/dev.c:4131
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4164
 __netlink_deliver_tap_skb net/netlink/af_netlink.c:294 [inline]
 __netlink_deliver_tap net/netlink/af_netlink.c:312 [inline]
 netlink_deliver_tap+0x9d4/0xe90 net/netlink/af_netlink.c:325
 netlink_deliver_tap_kernel net/netlink/af_netlink.c:334 [inline]
 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 netlink_unicast+0xe87/0x1100 net/netlink/af_netlink.c:1329
 netlink_sendmsg+0x1246/0x14d0 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0x1370/0x1400 net/socket.c:2352
 ___sys_sendmsg net/socket.c:2406 [inline]
 __sys_sendmsg+0x623/0x750 net/socket.c:2439
 __compat_sys_sendmsg net/compat.c:466 [inline]
 __do_compat_sys_socketcall net/compat.c:620 [inline]
 __se_compat_sys_socketcall+0xff2/0x1460 net/compat.c:543
 __ia32_compat_sys_socketcall+0x3e/0x60 net/compat.c:543
 do_syscall_32_irqs_on arch/x86/entry/common.c:430 [inline]
 __do_fast_syscall_32+0x2aa/0x400 arch/x86/entry/common.c:477
 do_fast_syscall_32+0x6b/0xd0 arch/x86/entry/common.c:505
 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:554
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
RIP: 0023:0xf7f99549
Code: Bad RIP value.
RSP: 002b:00000000f5d93e50 EFLAGS: 00000282 ORIG_RAX: 0000000000000066
RAX: ffffffffffffffda RBX: 0000000000000010 RCX: 00000000f5d93e64
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 00000000f5d93ecc
RBP: 00000000f5d94228 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline]
 kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:310
 __msan_chain_origin+0x50/0x90 mm/kmsan/kmsan_instr.c:165
 ___bpf_prog_run+0x6c64/0x97a0 kernel/bpf/core.c:1391
 __bpf_prog_run32+0x101/0x170 kernel/bpf/core.c:1681
 bpf_dispatcher_nop_func include/linux/bpf.h:556 [inline]
 bpf_prog_run_pin_on_cpu include/linux/filter.h:597 [inline]
 bpf_prog_run_clear_cb include/linux/filter.h:719 [inline]
 fanout_demux_bpf net/packet/af_packet.c:1404 [inline]
 packet_rcv_fanout+0x51e/0x25c0 net/packet/af_packet.c:1456
 deliver_skb net/core/dev.c:2247 [inline]
 dev_queue_xmit_nit+0x862/0x1280 net/core/dev.c:2317
 xmit_one net/core/dev.c:3552 [inline]
 dev_hard_start_xmit+0x20c/0xa70 net/core/dev.c:3572
 __dev_queue_xmit+0x2f8d/0x3b20 net/core/dev.c:4131
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4164
 __netlink_deliver_tap_skb net/netlink/af_netlink.c:294 [inline]
 __netlink_deliver_tap net/netlink/af_netlink.c:312 [inline]
 netlink_deliver_tap+0x9d4/0xe90 net/netlink/af_netlink.c:325
 netlink_deliver_tap_kernel net/netlink/af_netlink.c:334 [inline]
 netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline]
 netlink_unicast+0xe87/0x1100 net/netlink/af_netlink.c:1329
 netlink_sendmsg+0x1246/0x14d0 net/netlink/af_netlink.c:1918
 sock_sendmsg_nosec net/socket.c:652 [inline]
 sock_sendmsg net/socket.c:672 [inline]
 ____sys_sendmsg+0x1370/0x1400 net/socket.c:2352
 ___sys_sendmsg net/socket.c:2406 [inline]
 __sys_sendmsg+0x623/0x750 net/socket.c:2439
 __compat_sys_sendmsg net/compat.c:466 [inline]
 __do_compat_sys_socketcall net/compat.c:620 [inline]
 __se_compat_sys_socketcall+0xff2/0x1460 net/compat.c:543
 __ia32_compat_sys_socketcall+0x3e/0x60 net/compat.c:543
 do_syscall_32_irqs_on arch/x86/entry/common.c:430 [inline]
 __do_fast_syscall_32+0x2aa/0x400 arch/x86/entry/common.c:477
 do_fast_syscall_32+0x6b/0xd0 arch/x86/entry/common.c:505
 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:554
 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c

Local variable ----regs@__bpf_prog_run32 created at:
 __bpf_prog_run32+0x87/0x170 kernel/bpf/core.c:1681
 __bpf_prog_run32+0x87/0x170 kernel/bpf/core.c:1681
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