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BUG: KMSAN: uninit-value in bpf_prog_run_generic_xdp+0x190a/0x1f20 net/core/dev.c:5004
 bpf_prog_run_generic_xdp+0x190a/0x1f20 net/core/dev.c:5004
 netif_receive_generic_xdp net/core/dev.c:5086 [inline]
 do_xdp_generic+0xc0d/0x15a0 net/core/dev.c:5148
 tun_get_user+0x4903/0x6dd0 drivers/net/tun.c:1929
 tun_chr_write_iter+0x3ac/0x5d0 drivers/net/tun.c:2053
 new_sync_write fs/read_write.c:586 [inline]
 vfs_write+0xb2b/0x1540 fs/read_write.c:679
 ksys_write+0x240/0x4b0 fs/read_write.c:731
 __do_sys_write fs/read_write.c:742 [inline]
 __se_sys_write fs/read_write.c:739 [inline]
 __ia32_sys_write+0x91/0xe0 fs/read_write.c:739
 ia32_sys_call+0x2f4b/0x4180 arch/x86/include/generated/asm/syscalls_32.h:5
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0xb0/0x110 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x38/0x80 arch/x86/entry/common.c:411
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:449
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Uninit was stored to memory at:
 pskb_expand_head+0x305/0x1a60 net/core/skbuff.c:2283
 netif_skb_check_for_xdp net/core/dev.c:5049 [inline]
 netif_receive_generic_xdp net/core/dev.c:5080 [inline]
 do_xdp_generic+0x9e3/0x15a0 net/core/dev.c:5148
 tun_get_user+0x4903/0x6dd0 drivers/net/tun.c:1929
 tun_chr_write_iter+0x3ac/0x5d0 drivers/net/tun.c:2053
 new_sync_write fs/read_write.c:586 [inline]
 vfs_write+0xb2b/0x1540 fs/read_write.c:679
 ksys_write+0x240/0x4b0 fs/read_write.c:731
 __do_sys_write fs/read_write.c:742 [inline]
 __se_sys_write fs/read_write.c:739 [inline]
 __ia32_sys_write+0x91/0xe0 fs/read_write.c:739
 ia32_sys_call+0x2f4b/0x4180 arch/x86/include/generated/asm/syscalls_32.h:5
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0xb0/0x110 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x38/0x80 arch/x86/entry/common.c:411
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:449
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4110 [inline]
 slab_alloc_node mm/slub.c:4153 [inline]
 __do_kmalloc_node mm/slub.c:4282 [inline]
 __kmalloc_node_track_caller_noprof+0x945/0x1240 mm/slub.c:4302
 kmalloc_reserve+0x23e/0x4a0 net/core/skbuff.c:609
 __alloc_skb+0x363/0x7b0 net/core/skbuff.c:678
 alloc_skb include/linux/skbuff.h:1323 [inline]
 alloc_skb_with_frags+0xc8/0xd00 net/core/skbuff.c:6612
 sock_alloc_send_pskb+0xa81/0xbf0 net/core/sock.c:2881
 tun_alloc_skb drivers/net/tun.c:1526 [inline]
 tun_get_user+0x1c81/0x6dd0 drivers/net/tun.c:1851
 tun_chr_write_iter+0x3ac/0x5d0 drivers/net/tun.c:2053
 new_sync_write fs/read_write.c:586 [inline]
 vfs_write+0xb2b/0x1540 fs/read_write.c:679
 ksys_write+0x240/0x4b0 fs/read_write.c:731
 __do_sys_write fs/read_write.c:742 [inline]
 __se_sys_write fs/read_write.c:739 [inline]
 __ia32_sys_write+0x91/0xe0 fs/read_write.c:739
 ia32_sys_call+0x2f4b/0x4180 arch/x86/include/generated/asm/syscalls_32.h:5
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0xb0/0x110 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x38/0x80 arch/x86/entry/common.c:411
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/common.c:449
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

CPU: 1 UID: 0 PID: 8293 Comm: syz.1.470 Not tainted 6.13.0-rc1-syzkaller-00239-g9a6e8c7c3a02 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
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