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BUG: KMSAN: uninit-value in fib_rule_port_inrange include/net/fib_rules.h:162 [inline]
BUG: KMSAN: uninit-value in fib4_rule_match+0x71d/0x740 net/ipv4/fib_rules.c:193
CPU: 0 PID: 14176 Comm: syz-executor2 Not tainted 4.17.0-rc5+ #103
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+0x185/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x149/0x260 mm/kmsan/kmsan.c:1084
 __msan_warning_32+0x6e/0xc0 mm/kmsan/kmsan_instr.c:686
 fib_rule_port_inrange include/net/fib_rules.h:162 [inline]
 fib4_rule_match+0x71d/0x740 net/ipv4/fib_rules.c:193
 fib_rule_match net/core/fib_rules.c:273 [inline]
 fib_rules_lookup+0xb12/0xe70 net/core/fib_rules.c:288
 __fib_lookup+0x1bc/0x360 net/ipv4/fib_rules.c:93
 fib_lookup include/net/ip_fib.h:322 [inline]
 __fib_validate_source net/ipv4/fib_frontend.c:353 [inline]
 fib_validate_source+0xc23/0x1d50 net/ipv4/fib_frontend.c:434
 ip_mc_validate_source net/ipv4/route.c:1604 [inline]
 ip_route_input_mc net/ipv4/route.c:1622 [inline]
 ip_route_input_rcu+0xbeb/0x6280 net/ipv4/route.c:2146
 ip_route_input_noref+0x10e/0x140 net/ipv4/route.c:2098
 ip_rcv_finish+0x631/0x1d00 net/ipv4/ip_input.c:347
 NF_HOOK include/linux/netfilter.h:288 [inline]
 ip_rcv+0x118a/0x16d0 net/ipv4/ip_input.c:492
 __netif_receive_skb_core+0x47ff/0x4ac0 net/core/dev.c:4592
 __netif_receive_skb net/core/dev.c:4657 [inline]
 netif_receive_skb_internal+0x49d/0x630 net/core/dev.c:4731
 netif_receive_skb+0x230/0x240 net/core/dev.c:4755
 tun_rx_batched drivers/net/tun.c:1558 [inline]
 tun_get_user+0x6b61/0x7e90 drivers/net/tun.c:1962
 tun_chr_write_iter+0x1d4/0x330 drivers/net/tun.c:1990
 do_iter_readv_writev+0x84d/0xa00 include/linux/fs.h:1778
 do_iter_write+0x30d/0xd40 fs/read_write.c:959
 vfs_writev fs/read_write.c:1004 [inline]
 do_writev+0x3be/0x820 fs/read_write.c:1039
 __do_sys_writev fs/read_write.c:1112 [inline]
 __se_sys_writev fs/read_write.c:1109 [inline]
 __x64_sys_writev+0xe1/0x120 fs/read_write.c:1109
 do_syscall_64+0x152/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4558c1
RSP: 002b:00007f86c818bba0 EFLAGS: 00000293 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 000000000000002a RCX: 00000000004558c1
RDX: 0000000000000001 RSI: 00007f86c818bbf0 RDI: 00000000000000fc
RBP: 0000000020359fd5 R08: 00000000000000fc R09: 0000000000000000
R10: 000000000000002a R11: 0000000000000293 R12: 00000000ffffffff
R13: 000000000000073e R14: 00000000006ffe70 R15: 0000000000000000

Local variable description: ----fl4.i@fib_validate_source
Variable was created at:
 fib_validate_source+0x127/0x1d50 net/ipv4/fib_frontend.c:410
 ip_mc_validate_source net/ipv4/route.c:1604 [inline]
 ip_route_input_mc net/ipv4/route.c:1622 [inline]
 ip_route_input_rcu+0xbeb/0x6280 net/ipv4/route.c:2146
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