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BUG: KMSAN: uninit-value in do_msgrcv+0x512/0x1ec0 ipc/msg.c:1048
CPU: 1 PID: 25533 Comm: syz-executor1 Not tainted 4.17.0+ #9
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+0x188/0x2a0 mm/kmsan/kmsan.c:1125
 __msan_warning_32+0x70/0xc0 mm/kmsan/kmsan_instr.c:620
 do_msgrcv+0x512/0x1ec0 ipc/msg.c:1048
 ksys_msgrcv ipc/msg.c:1184 [inline]
 __do_sys_msgrcv ipc/msg.c:1190 [inline]
 __se_sys_msgrcv ipc/msg.c:1187 [inline]
 __x64_sys_msgrcv+0x160/0x1b0 ipc/msg.c:1187
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x455a99
RSP: 002b:00007fa10cdd6c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000046
RAX: ffffffffffffffda RBX: 00007fa10cdd76d4 RCX: 0000000000455a99
RDX: 0000000000000001 RSI: 0000000020e88000 RDI: 0000000000028004
RBP: 000000000072bff0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 00000000004c0107 R14: 00000000004cf6c0 R15: 0000000000000002

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:282 [inline]
 kmsan_internal_poison_shadow+0xb8/0x1b0 mm/kmsan/kmsan.c:192
 kmsan_kmalloc+0x94/0x100 mm/kmsan/kmsan.c:318
 __kmalloc_node+0xe44/0x1200 mm/slub.c:3865
 kmalloc_node include/linux/slab.h:554 [inline]
 kvmalloc_node+0x197/0x2f0 mm/util.c:421
 kvmalloc include/linux/mm.h:550 [inline]
 newque+0xb4/0x7d0 ipc/msg.c:139
 ipcget_new ipc/util.c:315 [inline]
 ipcget+0x2ab/0xd70 ipc/util.c:653
 ksys_msgget ipc/msg.c:289 [inline]
 __do_sys_msgget ipc/msg.c:294 [inline]
 __se_sys_msgget ipc/msg.c:292 [inline]
 __x64_sys_msgget+0x14c/0x1d0 ipc/msg.c:292
 do_syscall_64+0x15b/0x230 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
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