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BUG: KMSAN: uninit-value in ____bpf_skb_get_nlattr net/core/filter.c:144 [inline]
BUG: KMSAN: uninit-value in bpf_skb_get_nlattr+0x145/0x290 net/core/filter.c:134
CPU: 0 PID: 28875 Comm: syz-executor.0 Not tainted 5.7.0-rc4-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+0x1c9/0x220 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
 ____bpf_skb_get_nlattr net/core/filter.c:144 [inline]
 bpf_skb_get_nlattr+0x145/0x290 net/core/filter.c:134
 ___bpf_prog_run+0x214d/0x97a0 kernel/bpf/core.c:1516
 __bpf_prog_run32+0x101/0x170 kernel/bpf/core.c:1681
 bpf_dispatcher_nop_func include/linux/bpf.h:545 [inline]
 bpf_prog_run_pin_on_cpu include/linux/filter.h:599 [inline]
 bpf_prog_run_clear_cb include/linux/filter.h:721 [inline]
 run_filter net/packet/af_packet.c:2012 [inline]
 packet_rcv+0x70f/0x2160 net/packet/af_packet.c:2085
 deliver_skb net/core/dev.c:2168 [inline]
 deliver_ptype_list_skb net/core/dev.c:2183 [inline]
 __netif_receive_skb_core+0x3d76/0x5870 net/core/dev.c:5146
 __netif_receive_skb_one_core net/core/dev.c:5186 [inline]
 __netif_receive_skb net/core/dev.c:5302 [inline]
 netif_receive_skb_internal net/core/dev.c:5392 [inline]
 netif_receive_skb+0x551/0xf20 net/core/dev.c:5451
 tun_rx_batched drivers/net/tun.c:1516 [inline]
 tun_get_user+0x6d60/0x71e0 drivers/net/tun.c:1963
 tun_chr_write_iter+0x1f2/0x360 drivers/net/tun.c:1992
 call_write_iter include/linux/fs.h:1907 [inline]
 new_sync_write fs/read_write.c:484 [inline]
 __vfs_write+0xa5a/0xca0 fs/read_write.c:497
 vfs_write+0x444/0x8e0 fs/read_write.c:559
 ksys_write+0x267/0x450 fs/read_write.c:612
 __do_sys_write fs/read_write.c:624 [inline]
 __se_sys_write+0x92/0xb0 fs/read_write.c:621
 __ia32_sys_write+0x4a/0x70 fs/read_write.c:621
 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline]
 do_fast_syscall_32+0x3bf/0x6d0 arch/x86/entry/common.c:398
 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7f10dd9
Code: 90 e8 0b 00 00 00 f3 90 0f ae e8 eb f9 8d 74 26 00 89 3c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f5d0b0c4 EFLAGS: 00000296 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 00000000000000f0 RCX: 0000000020000000
RDX: 000000000000005e RSI: 0000000008113e38 RDI: 0000000000000bae
RBP: 00000000f5d0b168 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+0x6cbe/0x97a0 kernel/bpf/core.c:1391
 __bpf_prog_run32+0x101/0x170 kernel/bpf/core.c:1681
 bpf_dispatcher_nop_func include/linux/bpf.h:545 [inline]
 bpf_prog_run_pin_on_cpu include/linux/filter.h:599 [inline]
 bpf_prog_run_clear_cb include/linux/filter.h:721 [inline]
 run_filter net/packet/af_packet.c:2012 [inline]
 packet_rcv+0x70f/0x2160 net/packet/af_packet.c:2085
 deliver_skb net/core/dev.c:2168 [inline]
 deliver_ptype_list_skb net/core/dev.c:2183 [inline]
 __netif_receive_skb_core+0x3d76/0x5870 net/core/dev.c:5146
 __netif_receive_skb_one_core net/core/dev.c:5186 [inline]
 __netif_receive_skb net/core/dev.c:5302 [inline]
 netif_receive_skb_internal net/core/dev.c:5392 [inline]
 netif_receive_skb+0x551/0xf20 net/core/dev.c:5451
 tun_rx_batched drivers/net/tun.c:1516 [inline]
 tun_get_user+0x6d60/0x71e0 drivers/net/tun.c:1963
 tun_chr_write_iter+0x1f2/0x360 drivers/net/tun.c:1992
 call_write_iter include/linux/fs.h:1907 [inline]
 new_sync_write fs/read_write.c:484 [inline]
 __vfs_write+0xa5a/0xca0 fs/read_write.c:497
 vfs_write+0x444/0x8e0 fs/read_write.c:559
 ksys_write+0x267/0x450 fs/read_write.c:612
 __do_sys_write fs/read_write.c:624 [inline]
 __se_sys_write+0x92/0xb0 fs/read_write.c:621
 __ia32_sys_write+0x4a/0x70 fs/read_write.c:621
 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline]
 do_fast_syscall_32+0x3bf/0x6d0 arch/x86/entry/common.c:398
 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139

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:545 [inline]
 bpf_prog_run_pin_on_cpu include/linux/filter.h:599 [inline]
 bpf_prog_run_clear_cb include/linux/filter.h:721 [inline]
 run_filter net/packet/af_packet.c:2012 [inline]
 packet_rcv+0x70f/0x2160 net/packet/af_packet.c:2085
 deliver_skb net/core/dev.c:2168 [inline]
 deliver_ptype_list_skb net/core/dev.c:2183 [inline]
 __netif_receive_skb_core+0x3d76/0x5870 net/core/dev.c:5146
 __netif_receive_skb_one_core net/core/dev.c:5186 [inline]
 __netif_receive_skb net/core/dev.c:5302 [inline]
 netif_receive_skb_internal net/core/dev.c:5392 [inline]
 netif_receive_skb+0x551/0xf20 net/core/dev.c:5451
 tun_rx_batched drivers/net/tun.c:1516 [inline]
 tun_get_user+0x6d60/0x71e0 drivers/net/tun.c:1963
 tun_chr_write_iter+0x1f2/0x360 drivers/net/tun.c:1992
 call_write_iter include/linux/fs.h:1907 [inline]
 new_sync_write fs/read_write.c:484 [inline]
 __vfs_write+0xa5a/0xca0 fs/read_write.c:497
 vfs_write+0x444/0x8e0 fs/read_write.c:559
 ksys_write+0x267/0x450 fs/read_write.c:612
 __do_sys_write fs/read_write.c:624 [inline]
 __se_sys_write+0x92/0xb0 fs/read_write.c:621
 __ia32_sys_write+0x4a/0x70 fs/read_write.c:621
 do_syscall_32_irqs_on arch/x86/entry/common.c:339 [inline]
 do_fast_syscall_32+0x3bf/0x6d0 arch/x86/entry/common.c:398
 entry_SYSENTER_compat+0x68/0x77 arch/x86/entry/entry_64_compat.S:139

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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