===================================================== BUG: KMSAN: uninit-value in ip_tunnel_xmit+0x592/0x3a80 net/ipv4/ip_tunnel.c:654 CPU: 0 PID: 12389 Comm: syz-executor.5 Not tainted 5.10.0-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+0x21c/0x280 lib/dump_stack.c:118 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:118 __msan_warning+0x5f/0xa0 mm/kmsan/kmsan_instr.c:197 ip_tunnel_xmit+0x592/0x3a80 net/ipv4/ip_tunnel.c:654 __gre_xmit net/ipv4/ip_gre.c:466 [inline] ipgre_xmit+0x111e/0x11e0 net/ipv4/ip_gre.c:648 __netdev_start_xmit include/linux/netdevice.h:4718 [inline] netdev_start_xmit include/linux/netdevice.h:4732 [inline] xmit_one+0x2b6/0x760 net/core/dev.c:3564 dev_hard_start_xmit net/core/dev.c:3580 [inline] __dev_queue_xmit+0x3426/0x4590 net/core/dev.c:4140 dev_queue_xmit+0x4b/0x60 net/core/dev.c:4173 __bpf_tx_skb net/core/filter.c:2116 [inline] __bpf_redirect_no_mac net/core/filter.c:2141 [inline] __bpf_redirect+0xdb2/0x1700 net/core/filter.c:2164 ____bpf_clone_redirect net/core/filter.c:2448 [inline] bpf_clone_redirect+0x4a1/0x660 net/core/filter.c:2420 ___bpf_prog_run+0x4279/0x93e0 kernel/bpf/core.c:1521 __bpf_prog_run512+0x12e/0x190 kernel/bpf/core.c:1699 bpf_test_run+0x54c/0xe40 include/linux/filter.h:743 bpf_prog_test_run_skb+0x1906/0x34f0 net/bpf/test_run.c:581 bpf_prog_test_run kernel/bpf/syscall.c:3125 [inline] __do_sys_bpf+0xbfd9/0x1aee0 kernel/bpf/syscall.c:4417 __se_sys_bpf+0x8e/0xa0 kernel/bpf/syscall.c:4357 __ia32_sys_bpf+0x4a/0x70 kernel/bpf/syscall.c:4357 do_syscall_32_irqs_on arch/x86/entry/common.c:80 [inline] __do_fast_syscall_32+0x102/0x160 arch/x86/entry/common.c:139 do_fast_syscall_32+0x6a/0xc0 arch/x86/entry/common.c:162 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:205 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c RIP: 0023:0xf7f83549 Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 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:00000000f553b0cc EFLAGS: 00000296 ORIG_RAX: 0000000000000165 RAX: ffffffffffffffda RBX: 000000000000000a RCX: 0000000020000080 RDX: 000000000000002c RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline] kmsan_internal_poison_shadow+0x5c/0xf0 mm/kmsan/kmsan.c:104 kmsan_slab_alloc+0x8d/0xe0 mm/kmsan/kmsan_hooks.c:76 slab_alloc_node mm/slub.c:2906 [inline] __kmalloc_node_track_caller+0xa48/0x1610 mm/slub.c:4512 __kmalloc_reserve net/core/skbuff.c:142 [inline] pskb_expand_head+0x25e/0x1e20 net/core/skbuff.c:1622 skb_ensure_writable+0x4cf/0x590 net/core/skbuff.c:5452 __bpf_try_make_writable net/core/filter.c:1654 [inline] bpf_try_make_writable net/core/filter.c:1660 [inline] bpf_try_make_head_writable net/core/filter.c:1668 [inline] ____bpf_clone_redirect net/core/filter.c:2442 [inline] bpf_clone_redirect+0x25d/0x660 net/core/filter.c:2420 ___bpf_prog_run+0x4279/0x93e0 kernel/bpf/core.c:1521 __bpf_prog_run512+0x12e/0x190 kernel/bpf/core.c:1699 bpf_test_run+0x54c/0xe40 include/linux/filter.h:743 bpf_prog_test_run_skb+0x1906/0x34f0 net/bpf/test_run.c:581 bpf_prog_test_run kernel/bpf/syscall.c:3125 [inline] __do_sys_bpf+0xbfd9/0x1aee0 kernel/bpf/syscall.c:4417 __se_sys_bpf+0x8e/0xa0 kernel/bpf/syscall.c:4357 __ia32_sys_bpf+0x4a/0x70 kernel/bpf/syscall.c:4357 do_syscall_32_irqs_on arch/x86/entry/common.c:80 [inline] __do_fast_syscall_32+0x102/0x160 arch/x86/entry/common.c:139 do_fast_syscall_32+0x6a/0xc0 arch/x86/entry/common.c:162 do_SYSENTER_32+0x73/0x90 arch/x86/entry/common.c:205 entry_SYSENTER_compat_after_hwframe+0x4d/0x5c =====================================================