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BUG: KMSAN: uninit-value in eth_type_trans+0x68f/0xae0 net/ethernet/eth.c:176
 eth_type_trans+0x68f/0xae0 net/ethernet/eth.c:176
 loopback_xmit+0x4d2/0x720 drivers/net/loopback.c:87
 __netdev_start_xmit include/linux/netdevice.h:5368 [inline]
 netdev_start_xmit include/linux/netdevice.h:5377 [inline]
 xmit_one net/core/dev.c:3888 [inline]
 dev_hard_start_xmit+0x22f/0xa80 net/core/dev.c:3904
 __dev_queue_xmit+0x2990/0x5a00 net/core/dev.c:4870
 dev_queue_xmit include/linux/netdevice.h:3418 [inline]
 raw_sendmsg+0x65e/0xe30 net/ieee802154/socket.c:299
 ieee802154_sock_sendmsg+0x91/0xe0 net/ieee802154/socket.c:96
 sock_sendmsg_nosec net/socket.c:787 [inline]
 __sock_sendmsg net/socket.c:802 [inline]
 sock_write_iter+0x728/0x7e0 net/socket.c:1254
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0xbe1/0x15c0 fs/read_write.c:688
 ksys_write+0x1d9/0x470 fs/read_write.c:740
 __do_sys_write fs/read_write.c:751 [inline]
 __se_sys_write fs/read_write.c:748 [inline]
 __ia32_sys_write+0x9a/0xf0 fs/read_write.c:748
 ia32_sys_call+0x37a7/0x4360 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+0x180/0x460 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x37/0x80 arch/x86/entry/syscall_32.c:332
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/syscall_32.c:370
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Uninit was created at:
 slab_post_alloc_hook mm/slub.c:4576 [inline]
 slab_alloc_node mm/slub.c:4898 [inline]
 kmem_cache_alloc_node_noprof+0x3cd/0x12c0 mm/slub.c:4950
 kmalloc_reserve net/core/skbuff.c:613 [inline]
 __alloc_skb+0x855/0x1190 net/core/skbuff.c:713
 alloc_skb include/linux/skbuff.h:1383 [inline]
 alloc_skb_with_frags+0xc5/0x990 net/core/skbuff.c:6734
 sock_alloc_send_pskb+0xacb/0xc60 net/core/sock.c:2998
 sock_alloc_send_skb include/net/sock.h:1897 [inline]
 raw_sendmsg+0x331/0xe30 net/ieee802154/socket.c:282
 ieee802154_sock_sendmsg+0x91/0xe0 net/ieee802154/socket.c:96
 sock_sendmsg_nosec net/socket.c:787 [inline]
 __sock_sendmsg net/socket.c:802 [inline]
 sock_write_iter+0x728/0x7e0 net/socket.c:1254
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0xbe1/0x15c0 fs/read_write.c:688
 ksys_write+0x1d9/0x470 fs/read_write.c:740
 __do_sys_write fs/read_write.c:751 [inline]
 __se_sys_write fs/read_write.c:748 [inline]
 __ia32_sys_write+0x9a/0xf0 fs/read_write.c:748
 ia32_sys_call+0x37a7/0x4360 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+0x180/0x460 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x37/0x80 arch/x86/entry/syscall_32.c:332
 do_SYSENTER_32+0x1f/0x30 arch/x86/entry/syscall_32.c:370
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

CPU: 1 UID: 0 PID: 15630 Comm: syz.4.1302 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
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