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BUG: KMSAN: uninit-value in memcmp lib/string.c:950 [inline]
BUG: KMSAN: uninit-value in bcmp+0x127/0x180 lib/string.c:972
CPU: 0 PID: 8470 Comm: kworker/0:3 Not tainted 5.10.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: ipv6_addrconf addrconf_dad_work
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x21c/0x280 lib/dump_stack.c:118
 kmsan_report+0xfb/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x5f/0xa0 mm/kmsan/kmsan_instr.c:197
 memcmp lib/string.c:950 [inline]
 bcmp+0x127/0x180 lib/string.c:972
 __hw_addr_add_ex net/core/dev_addr_lists.c:57 [inline]
 __dev_mc_add+0x257/0x980 net/core/dev_addr_lists.c:775
 dev_mc_add+0x6d/0x80 net/core/dev_addr_lists.c:792
 igmp6_group_added+0x348/0xdc0 net/ipv6/mcast.c:669
 __ipv6_dev_mc_inc+0x11be/0x1570 net/ipv6/mcast.c:928
 ipv6_dev_mc_inc+0x70/0x80 net/ipv6/mcast.c:935
 addrconf_join_solict net/ipv6/addrconf.c:2167 [inline]
 addrconf_dad_begin net/ipv6/addrconf.c:3933 [inline]
 addrconf_dad_work+0x43e/0x3410 net/ipv6/addrconf.c:4060
 process_one_work+0x1219/0x1fe0 kernel/workqueue.c:2272
 worker_thread+0x123c/0x2730 kernel/workqueue.c:2418
 kthread+0x51c/0x560 kernel/kthread.c:292
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296

Local variable ----buf@igmp6_group_added created at:
 igmp6_group_added+0xa7/0xdc0 net/ipv6/mcast.c:659
 igmp6_group_added+0xa7/0xdc0 net/ipv6/mcast.c:659
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