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BUG: KMSAN: uninit-value in bpf_prog_run_generic_xdp+0x14a3/0x1ff0 net/core/dev.c:5291
 bpf_prog_run_generic_xdp+0x14a3/0x1ff0 net/core/dev.c:5291
 netif_receive_generic_xdp net/core/dev.c:5376 [inline]
 do_xdp_generic+0xd52/0x1690 net/core/dev.c:5438
 __netif_receive_skb_core+0x2533/0x70c0 net/core/dev.c:5788
 __netif_receive_skb_one_core net/core/dev.c:5975 [inline]
 __netif_receive_skb+0xcc/0xac0 net/core/dev.c:6090
 process_backlog+0x485/0xa00 net/core/dev.c:6442
 __napi_poll+0xda/0x9c0 net/core/dev.c:7414
 napi_poll net/core/dev.c:7478 [inline]
 net_rx_action+0xa59/0x1ac0 net/core/dev.c:7605
 handle_softirqs+0x166/0x6e0 kernel/softirq.c:579
 __do_softirq+0x14/0x1b kernel/softirq.c:613
 do_softirq+0x99/0x100 kernel/softirq.c:480
 __local_bh_enable_ip+0xa1/0xb0 kernel/softirq.c:407
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 tun_rx_batched+0x889/0x980 drivers/net/tun.c:-1
 tun_get_user+0x4ee0/0x6b40 drivers/net/tun.c:1938
 tun_chr_write_iter+0x3e9/0x5c0 drivers/net/tun.c:1984
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0xb4b/0x1580 fs/read_write.c:686
 ksys_write fs/read_write.c:738 [inline]
 __do_sys_write fs/read_write.c:749 [inline]
 __se_sys_write fs/read_write.c:746 [inline]
 __ia32_sys_write+0x1f9/0x4d0 fs/read_write.c:746
 ia32_sys_call+0x30f2/0x42c0 arch/x86/include/generated/asm/syscalls_32.h:5
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xb0/0x150 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x38/0x80 arch/x86/entry/syscall_32.c:331
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/syscall_32.c:369
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Uninit was created at:
 __alloc_frozen_pages_noprof+0x689/0xf00 mm/page_alloc.c:4982
 alloc_pages_mpol+0x328/0x860 mm/mempolicy.c:2419
 alloc_frozen_pages_noprof mm/mempolicy.c:2490 [inline]
 alloc_pages_noprof+0x102/0x280 mm/mempolicy.c:2510
 skb_page_frag_refill+0x3d8/0x730 net/core/sock.c:3150
 tun_build_skb drivers/net/tun.c:1620 [inline]
 tun_get_user+0x1c28/0x6b40 drivers/net/tun.c:1758
 tun_chr_write_iter+0x3e9/0x5c0 drivers/net/tun.c:1984
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0xb4b/0x1580 fs/read_write.c:686
 ksys_write fs/read_write.c:738 [inline]
 __do_sys_write fs/read_write.c:749 [inline]
 __se_sys_write fs/read_write.c:746 [inline]
 __ia32_sys_write+0x1f9/0x4d0 fs/read_write.c:746
 ia32_sys_call+0x30f2/0x42c0 arch/x86/include/generated/asm/syscalls_32.h:5
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xb0/0x150 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x38/0x80 arch/x86/entry/syscall_32.c:331
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/syscall_32.c:369
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

CPU: 0 UID: 0 PID: 11621 Comm: syz.6.1576 Not tainted 6.16.0-rc5-syzkaller-00053-g8c2e52ebbe88 #0 PREEMPT(none) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
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