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BUG: KMSAN: uninit-value in netif_receive_generic_xdp+0x15c9/0x2530 net/core/dev.c:4675
CPU: 0 PID: 9 Comm: ksoftirqd/0 Not tainted 5.9.0-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+0xf7/0x1e0 mm/kmsan/kmsan_report.c:122
 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:219
 netif_receive_generic_xdp+0x15c9/0x2530 net/core/dev.c:4675
 do_xdp_generic net/core/dev.c:4740 [inline]
 __netif_receive_skb_core+0x823/0x6520 net/core/dev.c:5112
 __netif_receive_skb_one_core net/core/dev.c:5284 [inline]
 __netif_receive_skb+0x164/0x670 net/core/dev.c:5400
 process_backlog+0x50d/0xba0 net/core/dev.c:6242
 napi_poll+0x443/0x1100 net/core/dev.c:6688
 net_rx_action+0x35c/0xd40 net/core/dev.c:6758
 __do_softirq+0x2ea/0x7f5 kernel/softirq.c:299
 run_ksoftirqd+0x25/0x40 kernel/softirq.c:656
 smpboot_thread_fn+0x5f5/0xa90 kernel/smpboot.c:165
 kthread+0x551/0x590 kernel/kthread.c:293
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:143 [inline]
 kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:311
 kmsan_memcpy_memmove_metadata+0x272/0x2e0 mm/kmsan/kmsan.c:248
 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:268
 __msan_memcpy+0x43/0x50 mm/kmsan/kmsan_instr.c:120
 pskb_expand_head+0x3fd/0x1e30 net/core/skbuff.c:1638
 netif_receive_generic_xdp+0x629/0x2530 net/core/dev.c:4621
 do_xdp_generic net/core/dev.c:4740 [inline]
 __netif_receive_skb_core+0x823/0x6520 net/core/dev.c:5112
 __netif_receive_skb_one_core net/core/dev.c:5284 [inline]
 __netif_receive_skb+0x164/0x670 net/core/dev.c:5400
 process_backlog+0x50d/0xba0 net/core/dev.c:6242
 napi_poll+0x443/0x1100 net/core/dev.c:6688
 net_rx_action+0x35c/0xd40 net/core/dev.c:6758
 __do_softirq+0x2ea/0x7f5 kernel/softirq.c:299

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:143 [inline]
 kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:126
 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:80
 slab_alloc_node mm/slub.c:2907 [inline]
 __kmalloc_node_track_caller+0x9aa/0x12f0 mm/slub.c:4511
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0x35f/0xb30 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1094 [inline]
 alloc_skb_with_frags+0x1f2/0xc10 net/core/skbuff.c:5771
 sock_alloc_send_pskb+0xc83/0xe50 net/core/sock.c:2348
 sock_alloc_send_skb+0xca/0xe0 net/core/sock.c:2365
 j1939_sk_alloc_skb net/can/j1939/socket.c:857 [inline]
 j1939_sk_send_loop net/can/j1939/socket.c:1039 [inline]
 j1939_sk_sendmsg+0xe11/0x2950 net/can/j1939/socket.c:1174
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 ____sys_sendmsg+0xc82/0x1240 net/socket.c:2353
 ___sys_sendmsg net/socket.c:2407 [inline]
 __sys_sendmsg+0x6d1/0x820 net/socket.c:2440
 __compat_sys_sendmsg net/compat.c:347 [inline]
 __do_compat_sys_sendmsg net/compat.c:354 [inline]
 __se_compat_sys_sendmsg+0xa7/0xc0 net/compat.c:351
 __ia32_compat_sys_sendmsg+0x4a/0x70 net/compat.c:351
 do_syscall_32_irqs_on arch/x86/entry/common.c:80 [inline]
 __do_fast_syscall_32+0x129/0x180 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
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