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BUG: KMSAN: use-after-free in __alloc_skb+0x215/0xa10 net/core/skbuff.c:197
CPU: 1 PID: 28215 Comm: syz-executor.0 Not tainted 5.4.0-rc2+ #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+0x153/0x2c0 mm/kmsan/kmsan_report.c:113
 __msan_warning+0x73/0xe0 mm/kmsan/kmsan_instr.c:250
 slab_alloc_node mm/slub.c:2751 [inline]
 kmem_cache_alloc_node+0x5d0/0xe70 mm/slub.c:2830
 __alloc_skb+0x215/0xa10 net/core/skbuff.c:197
 skb_segment+0x1b95/0x6510 net/core/skbuff.c:3809
 tcp_gso_segment+0x83d/0x2680 net/ipv4/tcp_offload.c:98
 tcp6_gso_segment+0x20a/0x740 net/ipv6/tcpv6_offload.c:65
 ipv6_gso_segment+0x128f/0x1f10 net/ipv6/ip6_offload.c:113
 skb_mac_gso_segment+0x3fa/0x720 net/core/dev.c:3037
 __skb_gso_segment+0x71d/0xa20 net/core/dev.c:3110
 skb_gso_segment include/linux/netdevice.h:4370 [inline]
 validate_xmit_skb+0xcfd/0x1680 net/core/dev.c:3350
 validate_xmit_skb_list+0x17b/0x380 net/core/dev.c:3400
 sch_direct_xmit+0x1c5/0x18c0 net/sched/sch_generic.c:299
 __dev_xmit_skb net/core/dev.c:3481 [inline]
 __dev_queue_xmit+0x212d/0x4200 net/core/dev.c:3842
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3906
 packet_snd net/packet/af_packet.c:2959 [inline]
 packet_sendmsg+0x82d7/0x92e0 net/packet/af_packet.c:2984
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg net/socket.c:657 [inline]
 __sys_sendto+0xc44/0xc70 net/socket.c:1952
 __do_sys_sendto net/socket.c:1964 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:1960
 __x64_sys_sendto+0x6e/0x90 net/socket.c:1960
 do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x459a59
Code: fd b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f7dbd524c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000459a59
RDX: 000000000000306c RSI: 0000000020000080 RDI: 0000000000000003
RBP: 000000000075bf20 R08: 0000000000000000 R09: 00000000000002ff
R10: 0000000004000002 R11: 0000000000000246 R12: 00007f7dbd5256d4
R13: 00000000004c7c6d R14: 00000000004dda70 R15: 00000000ffffffff

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:154 [inline]
 kmsan_internal_chain_origin+0xde/0x190 mm/kmsan/kmsan.c:325
 __msan_chain_origin+0x6b/0xe0 mm/kmsan/kmsan_instr.c:184
 ___slab_alloc+0x1dbc/0x1fb0 mm/slub.c:2636
 __slab_alloc mm/slub.c:2689 [inline]
 slab_alloc_node mm/slub.c:2752 [inline]
 kmem_cache_alloc_node+0x769/0xe70 mm/slub.c:2830
 __alloc_skb+0x215/0xa10 net/core/skbuff.c:197
 skb_segment+0x1b95/0x6510 net/core/skbuff.c:3809
 tcp_gso_segment+0x83d/0x2680 net/ipv4/tcp_offload.c:98
 tcp6_gso_segment+0x20a/0x740 net/ipv6/tcpv6_offload.c:65
 ipv6_gso_segment+0x128f/0x1f10 net/ipv6/ip6_offload.c:113
 skb_mac_gso_segment+0x3fa/0x720 net/core/dev.c:3037
 __skb_gso_segment+0x71d/0xa20 net/core/dev.c:3110
 skb_gso_segment include/linux/netdevice.h:4370 [inline]
 validate_xmit_skb+0xcfd/0x1680 net/core/dev.c:3350
 validate_xmit_skb_list+0x17b/0x380 net/core/dev.c:3400
 sch_direct_xmit+0x1c5/0x18c0 net/sched/sch_generic.c:299
 __dev_xmit_skb net/core/dev.c:3481 [inline]
 __dev_queue_xmit+0x212d/0x4200 net/core/dev.c:3842
 dev_queue_xmit+0x4b/0x60 net/core/dev.c:3906
 packet_snd net/packet/af_packet.c:2959 [inline]
 packet_sendmsg+0x82d7/0x92e0 net/packet/af_packet.c:2984
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg net/socket.c:657 [inline]
 __sys_sendto+0xc44/0xc70 net/socket.c:1952
 __do_sys_sendto net/socket.c:1964 [inline]
 __se_sys_sendto+0x107/0x130 net/socket.c:1960
 __x64_sys_sendto+0x6e/0x90 net/socket.c:1960
 do_syscall_64+0xb6/0x160 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:154 [inline]
 kmsan_internal_poison_shadow+0x60/0x120 mm/kmsan/kmsan.c:137
 kmsan_slab_free+0x8d/0x100 mm/kmsan/kmsan_hooks.c:123
 slab_free_freelist_hook mm/slub.c:1473 [inline]
 slab_free mm/slub.c:3040 [inline]
 kmem_cache_free_bulk+0x3ad9/0x3f10 mm/slub.c:3165
 __kfree_skb_flush+0xb0/0x100 net/core/skbuff.c:862
 net_rx_action+0x1a5e/0x1aa0 net/core/dev.c:6483
 __do_softirq+0x4a1/0x83a kernel/softirq.c:293
 run_ksoftirqd+0x25/0x40 kernel/softirq.c:607
 smpboot_thread_fn+0x4a3/0x990 kernel/smpboot.c:165
 kthread+0x4b5/0x4f0 kernel/kthread.c:256
 ret_from_fork+0x35/0x40 arch/x86/entry/entry_64.S:355
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