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BUG: KMSAN: uninit-value in slab_alloc_node mm/slub.c:2738 [inline]
BUG: KMSAN: uninit-value in __kmalloc_node_track_caller+0x82f/0x11b0 mm/slub.c:4395
CPU: 1 PID: 13833 Comm: syz-executor687 Not tainted 4.17.0-rc5+ #103
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+0x185/0x1d0 lib/dump_stack.c:113
 kmsan_report+0x149/0x260 mm/kmsan/kmsan.c:1084
 __msan_warning_32+0x6e/0xc0 mm/kmsan/kmsan_instr.c:686
 slab_alloc_node mm/slub.c:2738 [inline]
 __kmalloc_node_track_caller+0x82f/0x11b0 mm/slub.c:4395
 __kmalloc_reserve net/core/skbuff.c:138 [inline]
 __alloc_skb+0x2cb/0x9e0 net/core/skbuff.c:206
 alloc_skb_fclone include/linux/skbuff.h:1030 [inline]
 sk_stream_alloc_skb+0x17c/0xcf0 net/ipv4/tcp.c:875
 tcp_sendmsg_locked+0x237e/0x6610 net/ipv4/tcp.c:1290
 tcp_sendmsg+0xb2/0x100 net/ipv4/tcp.c:1447
 inet_sendmsg+0x3f7/0x750 net/ipv4/af_inet.c:798
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg net/socket.c:639 [inline]
 sock_write_iter+0x3b7/0x470 net/socket.c:908
 call_write_iter include/linux/fs.h:1784 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x7fb/0x9f0 fs/read_write.c:487
 vfs_write+0x467/0x8c0 fs/read_write.c:549
 ksys_write fs/read_write.c:598 [inline]
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x1bf/0x3e0 fs/read_write.c:607
 do_syscall_64+0x152/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x4480c9
RSP: 002b:00007f2aa5f5cdb8 EFLAGS: 00000297 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00000000006f0024 RCX: 00000000004480c9
RDX: 00000000ffffffe7 RSI: 00000000200000c0 RDI: 0000000000000003
RBP: 00000000006f0020 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000000
R13: 00000000007ffb7f R14: 00007f2aa5f5d9c0 R15: 0000000000000005

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:279 [inline]
 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:189
 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:315
 kmsan_slab_alloc+0x10/0x20 mm/kmsan/kmsan.c:322
 slab_post_alloc_hook mm/slab.h:446 [inline]
 slab_alloc_node mm/slub.c:2753 [inline]
 __kmalloc_node_track_caller+0xb32/0x11b0 mm/slub.c:4395
 __kmalloc_reserve net/core/skbuff.c:138 [inline]
 __alloc_skb+0x2cb/0x9e0 net/core/skbuff.c:206
 alloc_skb include/linux/skbuff.h:988 [inline]
 tcp_send_ack+0x188/0x900 net/ipv4/tcp_output.c:3597
 tcp_delack_timer_handler+0x5d0/0xac0 net/ipv4/tcp_timer.c:276
 tcp_delack_timer+0x1ae/0x350 net/ipv4/tcp_timer.c:303
 call_timer_fn+0x26a/0x5a0 kernel/time/timer.c:1326
 expire_timers kernel/time/timer.c:1363 [inline]
 __run_timers+0xda7/0x11c0 kernel/time/timer.c:1666
 run_timer_softirq+0x43/0x70 kernel/time/timer.c:1692
 __do_softirq+0x56d/0x93d kernel/softirq.c:285
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