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BUG: KMSAN: uninit-value in kfree_skbmem net/core/skbuff.c:644 [inline]
BUG: KMSAN: uninit-value in __kfree_skb net/core/skbuff.c:680 [inline]
BUG: KMSAN: uninit-value in kfree_skb+0x473/0x4c0 net/core/skbuff.c:697
CPU: 0 PID: 12401 Comm: syz-fuzzer Not tainted 5.3.0-rc7+ #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+0x191/0x1f0 lib/dump_stack.c:113
 kmsan_report+0x13a/0x2b0 mm/kmsan/kmsan_report.c:108
 __msan_warning+0x73/0xe0 mm/kmsan/kmsan_instr.c:250
 do_slab_free mm/slub.c:3016 [inline]
 slab_free mm/slub.c:3039 [inline]
 kmem_cache_free+0x3df/0x2b70 mm/slub.c:3054
 kfree_skbmem net/core/skbuff.c:644 [inline]
 __kfree_skb net/core/skbuff.c:680 [inline]
 kfree_skb+0x473/0x4c0 net/core/skbuff.c:697
 packet_rcv_spkt+0x719/0x840 net/packet/af_packet.c:1847
 dev_queue_xmit_nit+0x1125/0x1200 net/core/dev.c:2077
 xmit_one net/core/dev.c:3276 [inline]
 dev_hard_start_xmit+0x21e/0xab0 net/core/dev.c:3296
 sch_direct_xmit+0x56c/0x18c0 net/sched/sch_generic.c:309
 __dev_xmit_skb net/core/dev.c:3477 [inline]
 __dev_queue_xmit+0x1e53/0x4270 net/core/dev.c:3838
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3902
 neigh_hh_output include/net/neighbour.h:500 [inline]
 neigh_output include/net/neighbour.h:509 [inline]
 ip_finish_output2+0x20c6/0x25d0 net/ipv4/ip_output.c:228
 __ip_finish_output+0xaf8/0xda0 net/ipv4/ip_output.c:308
 ip_finish_output+0x2db/0x420 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip_output+0x541/0x610 net/ipv4/ip_output.c:432
 dst_output include/net/dst.h:436 [inline]
 ip_local_out net/ipv4/ip_output.c:125 [inline]
 __ip_queue_xmit+0x1caf/0x21f0 net/ipv4/ip_output.c:532
 ip_queue_xmit+0xcc/0xf0 include/net/ip.h:236
 __tcp_transmit_skb+0x409e/0x5c60 net/ipv4/tcp_output.c:1158
 __tcp_send_ack+0x701/0x840 net/ipv4/tcp_output.c:3685
 tcp_send_ack+0x68/0x90 net/ipv4/tcp_output.c:3691
 tcp_cleanup_rbuf+0x764/0x800 net/ipv4/tcp.c:1575
 tcp_recvmsg+0x334d/0x4ff0 net/ipv4/tcp.c:2179
 inet_recvmsg+0x237/0x7d0 net/ipv4/af_inet.c:838
 sock_recvmsg_nosec net/socket.c:871 [inline]
 sock_recvmsg net/socket.c:889 [inline]
 sock_read_iter+0x5be/0x660 net/socket.c:967
 call_read_iter include/linux/fs.h:1864 [inline]
 new_sync_read fs/read_write.c:414 [inline]
 __vfs_read+0xa67/0xc90 fs/read_write.c:427
 vfs_read+0x359/0x6f0 fs/read_write.c:461
 ksys_read+0x265/0x430 fs/read_write.c:587
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read+0x92/0xb0 fs/read_write.c:595
 __x64_sys_read+0x4a/0x70 fs/read_write.c:595
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x47fd44
Code: ff ff cc cc cc cc e8 9b 40 fb ff 48 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 45 31 d2 45 31 c0 45 31 c9 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 28 ff ff ff ff 48 c7 44 24 30
RSP: 002b:000000c42038f710 EFLAGS: 00000246 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 000000000047fd44
RDX: 0000000000001000 RSI: 000000c420356000 RDI: 0000000000000003
RBP: 000000c42038f760 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
R13: 0000000000000004 R14: 0000000000000004 R15: ffffffffffffffff

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:150 [inline]
 kmsan_internal_chain_origin+0xd2/0x170 mm/kmsan/kmsan.c:314
 __msan_chain_origin+0x6b/0xe0 mm/kmsan/kmsan_instr.c:184
 ___slab_alloc+0x1dbc/0x1fb0 mm/slub.c:2634
 __slab_alloc mm/slub.c:2687 [inline]
 slab_alloc_node mm/slub.c:2750 [inline]
 slab_alloc mm/slub.c:2799 [inline]
 kmem_cache_alloc+0xade/0xd10 mm/slub.c:2804
 skb_clone+0x326/0x5d0 net/core/skbuff.c:1448
 dev_queue_xmit_nit+0x539/0x1200 net/core/dev.c:2045
 xmit_one net/core/dev.c:3276 [inline]
 dev_hard_start_xmit+0x21e/0xab0 net/core/dev.c:3296
 sch_direct_xmit+0x56c/0x18c0 net/sched/sch_generic.c:309
 __dev_xmit_skb net/core/dev.c:3477 [inline]
 __dev_queue_xmit+0x1e53/0x4270 net/core/dev.c:3838
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3902
 neigh_hh_output include/net/neighbour.h:500 [inline]
 neigh_output include/net/neighbour.h:509 [inline]
 ip_finish_output2+0x20c6/0x25d0 net/ipv4/ip_output.c:228
 __ip_finish_output+0xaf8/0xda0 net/ipv4/ip_output.c:308
 ip_finish_output+0x2db/0x420 net/ipv4/ip_output.c:318
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip_output+0x541/0x610 net/ipv4/ip_output.c:432
 dst_output include/net/dst.h:436 [inline]
 ip_local_out net/ipv4/ip_output.c:125 [inline]
 __ip_queue_xmit+0x1caf/0x21f0 net/ipv4/ip_output.c:532
 ip_queue_xmit+0xcc/0xf0 include/net/ip.h:236
 __tcp_transmit_skb+0x409e/0x5c60 net/ipv4/tcp_output.c:1158
 __tcp_send_ack+0x701/0x840 net/ipv4/tcp_output.c:3685
 tcp_send_ack+0x68/0x90 net/ipv4/tcp_output.c:3691
 tcp_cleanup_rbuf+0x764/0x800 net/ipv4/tcp.c:1575
 tcp_recvmsg+0x334d/0x4ff0 net/ipv4/tcp.c:2179
 inet_recvmsg+0x237/0x7d0 net/ipv4/af_inet.c:838
 sock_recvmsg_nosec net/socket.c:871 [inline]
 sock_recvmsg net/socket.c:889 [inline]
 sock_read_iter+0x5be/0x660 net/socket.c:967
 call_read_iter include/linux/fs.h:1864 [inline]
 new_sync_read fs/read_write.c:414 [inline]
 __vfs_read+0xa67/0xc90 fs/read_write.c:427
 vfs_read+0x359/0x6f0 fs/read_write.c:461
 ksys_read+0x265/0x430 fs/read_write.c:587
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read+0x92/0xb0 fs/read_write.c:595
 __x64_sys_read+0x4a/0x70 fs/read_write.c:595
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:297
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:150 [inline]
 kmsan_internal_poison_shadow+0x53/0x100 mm/kmsan/kmsan.c:134
 kmsan_slab_free+0x8d/0x100 mm/kmsan/kmsan_hooks.c:123
 slab_free_freelist_hook mm/slub.c:1472 [inline]
 slab_free mm/slub.c:3038 [inline]
 kmem_cache_free_bulk+0x3ad9/0x3f50 mm/slub.c:3163
 __kfree_skb_flush+0xb0/0x100 net/core/skbuff.c:862
 net_rx_action+0x1908/0x1950 net/core/dev.c:6441
 __do_softirq+0x4a1/0x83a kernel/softirq.c:293
 invoke_softirq kernel/softirq.c:375 [inline]
 irq_exit+0x230/0x280 kernel/softirq.c:416
 exiting_irq arch/x86/include/asm/apic.h:537 [inline]
 do_IRQ+0x20d/0x3a0 arch/x86/kernel/irq.c:259
 ret_from_intr+0x0/0x33
 native_safe_halt arch/x86/include/asm/irqflags.h:60 [inline]
 arch_safe_halt arch/x86/include/asm/irqflags.h:103 [inline]
 default_idle+0x53/0x90 arch/x86/kernel/process.c:580
 arch_cpu_idle+0x25/0x30 arch/x86/kernel/process.c:571
 default_idle_call kernel/sched/idle.c:94 [inline]
 cpuidle_idle_call kernel/sched/idle.c:154 [inline]
 do_idle+0x1d7/0x790 kernel/sched/idle.c:263
 cpu_startup_entry+0x45/0x50 kernel/sched/idle.c:354
 rest_init+0x1be/0x1f0 init/main.c:452
 arch_call_rest_init+0x13/0x15
 start_kernel+0x991/0xb61 init/main.c:788
 x86_64_start_reservations+0x18/0x2e arch/x86/kernel/head64.c:472
 x86_64_start_kernel+0x81/0x84 arch/x86/kernel/head64.c:453
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:241
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