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BUG: KMSAN: uninit-value in bpf_prog_run_generic_xdp+0x13aa/0x1f20 net/core/dev.c:5208
 bpf_prog_run_generic_xdp+0x13aa/0x1f20 net/core/dev.c:5208
 netif_receive_generic_xdp net/core/dev.c:5290 [inline]
 do_xdp_generic+0xc10/0x15a0 net/core/dev.c:5352
 __netif_receive_skb_core+0x2506/0x7510 net/core/dev.c:5702
 __netif_receive_skb_one_core net/core/dev.c:5889 [inline]
 __netif_receive_skb+0xca/0xa00 net/core/dev.c:6004
 process_backlog+0x4ad/0xa50 net/core/dev.c:6356
 __napi_poll+0xe7/0x980 net/core/dev.c:7328
 napi_poll net/core/dev.c:7392 [inline]
 net_rx_action+0xa5a/0x19b0 net/core/dev.c:7514
 handle_softirqs+0x1a0/0x7c0 kernel/softirq.c:561
 __do_softirq+0x14/0x1a kernel/softirq.c:595
 do_softirq+0x9a/0x100 kernel/softirq.c:462
 __local_bh_enable_ip+0x9f/0xb0 kernel/softirq.c:389
 tun_rx_batched+0x89f/0x980 drivers/net/tun.c:-1
 tun_get_user+0x5505/0x6b80 drivers/net/tun.c:1938
 tun_chr_write_iter+0x3ac/0x5d0 drivers/net/tun.c:1984
 new_sync_write fs/read_write.c:591 [inline]
 vfs_write+0xb34/0x1540 fs/read_write.c:684
 ksys_write+0x240/0x4b0 fs/read_write.c:736
 __do_sys_write fs/read_write.c:747 [inline]
 __se_sys_write fs/read_write.c:744 [inline]
 __x64_sys_write+0x93/0xe0 fs/read_write.c:744
 x64_sys_call+0x34de/0x3c80 arch/x86/include/generated/asm/syscalls_64.h:2
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x1e0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4144 [inline]
 slab_alloc_node mm/slub.c:4187 [inline]
 __do_kmalloc_node mm/slub.c:4317 [inline]
 __kmalloc_node_track_caller_noprof+0x962/0x1260 mm/slub.c:4337
 kmalloc_reserve+0x23e/0x4a0 net/core/skbuff.c:599
 pskb_expand_head+0x21f/0x1c10 net/core/skbuff.c:2247
 netif_skb_check_for_xdp net/core/dev.c:5253 [inline]
 netif_receive_generic_xdp net/core/dev.c:5284 [inline]
 do_xdp_generic+0x9e6/0x15a0 net/core/dev.c:5352
 __netif_receive_skb_core+0x2506/0x7510 net/core/dev.c:5702
 __netif_receive_skb_one_core net/core/dev.c:5889 [inline]
 __netif_receive_skb+0xca/0xa00 net/core/dev.c:6004
 process_backlog+0x4ad/0xa50 net/core/dev.c:6356
 __napi_poll+0xe7/0x980 net/core/dev.c:7328
 napi_poll net/core/dev.c:7392 [inline]
 net_rx_action+0xa5a/0x19b0 net/core/dev.c:7514
 handle_softirqs+0x1a0/0x7c0 kernel/softirq.c:561
 __do_softirq+0x14/0x1a kernel/softirq.c:595

CPU: 0 UID: 0 PID: 11603 Comm: syz.0.1729 Not tainted 6.14.0-syzkaller-07540-geff5f16bfd87 #0 PREEMPT(undef) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
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