Hello, syzbot found the following crash on: HEAD commit: 14bcee29 DO-NOT-SUBMIT: kmsan: block: nullb: handle read r.. git tree: https://github.com/google/kmsan.git master console output: https://syzkaller.appspot.com/x/log.txt?x=14f266a4100000 kernel config: https://syzkaller.appspot.com/x/.config?x=6f048d804e1a47a0 dashboard link: https://syzkaller.appspot.com/bug?extid=e66172c53a40c795a780 compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) Unfortunately, I don't have any reproducer for this crash yet. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+e66172c53a40c795a780@xxxxxxxxxxxxxxxxxxxxxxxxx ===================================================== BUG: KMSAN: uninit-value in __read_once_size include/linux/compiler.h:206 [inline] BUG: KMSAN: uninit-value in hash_ip6_test+0x763/0x7e0 net/netfilter/ipset/ip_set_hash_gen.h:1253 CPU: 0 PID: 18186 Comm: syz-executor.1 Not tainted 5.7.0-rc4-syzkaller #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+0x1c9/0x220 lib/dump_stack.c:118 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118 __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 __read_once_size include/linux/compiler.h:206 [inline] hash_ip6_test+0x763/0x7e0 net/netfilter/ipset/ip_set_hash_gen.h:1253 hash_ip6_uadt+0x8e6/0xad0 net/netfilter/ipset/ip_set_hash_ip.c:267 ip_set_utest+0x657/0x820 net/netfilter/ipset/ip_set_core.c:1884 nfnetlink_rcv_msg+0xb86/0xcf0 net/netfilter/nfnetlink.c:229 netlink_rcv_skb+0x451/0x650 net/netlink/af_netlink.c:2469 nfnetlink_rcv+0x3b5/0x3ab0 net/netfilter/nfnetlink.c:563 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0xf9e/0x1100 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x1246/0x14d0 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x12b6/0x1350 net/socket.c:2362 ___sys_sendmsg net/socket.c:2416 [inline] __sys_sendmsg+0x623/0x750 net/socket.c:2449 __do_sys_sendmsg net/socket.c:2458 [inline] __se_sys_sendmsg+0x97/0xb0 net/socket.c:2456 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2456 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45c829 Code: 0d 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 db b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f55a0374c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000004fd960 RCX: 000000000045c829 RDX: 0000000000000000 RSI: 0000000020000300 RDI: 0000000000000003 RBP: 000000000078bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000936 R14: 00000000004cbda5 R15: 00007f55a03756d4 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:310 __msan_chain_origin+0x50/0x90 mm/kmsan/kmsan_instr.c:165 ip6_netmask include/linux/netfilter/ipset/pfxlen.h:49 [inline] hash_ip6_netmask net/netfilter/ipset/ip_set_hash_ip.c:185 [inline] hash_ip6_uadt+0x9df/0xad0 net/netfilter/ipset/ip_set_hash_ip.c:263 ip_set_utest+0x657/0x820 net/netfilter/ipset/ip_set_core.c:1884 nfnetlink_rcv_msg+0xb86/0xcf0 net/netfilter/nfnetlink.c:229 netlink_rcv_skb+0x451/0x650 net/netlink/af_netlink.c:2469 nfnetlink_rcv+0x3b5/0x3ab0 net/netfilter/nfnetlink.c:563 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0xf9e/0x1100 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x1246/0x14d0 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x12b6/0x1350 net/socket.c:2362 ___sys_sendmsg net/socket.c:2416 [inline] __sys_sendmsg+0x623/0x750 net/socket.c:2449 __do_sys_sendmsg net/socket.c:2458 [inline] __se_sys_sendmsg+0x97/0xb0 net/socket.c:2456 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2456 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Uninit was stored to memory at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:310 kmsan_memcpy_memmove_metadata+0x272/0x2e0 mm/kmsan/kmsan.c:247 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:267 __msan_memcpy+0x43/0x50 mm/kmsan/kmsan_instr.c:116 ip_set_get_ipaddr6+0x26a/0x300 net/netfilter/ipset/ip_set_core.c:325 hash_ip6_uadt+0x450/0xad0 net/netfilter/ipset/ip_set_hash_ip.c:255 ip_set_utest+0x657/0x820 net/netfilter/ipset/ip_set_core.c:1884 nfnetlink_rcv_msg+0xb86/0xcf0 net/netfilter/nfnetlink.c:229 netlink_rcv_skb+0x451/0x650 net/netlink/af_netlink.c:2469 nfnetlink_rcv+0x3b5/0x3ab0 net/netfilter/nfnetlink.c:563 netlink_unicast_kernel net/netlink/af_netlink.c:1303 [inline] netlink_unicast+0xf9e/0x1100 net/netlink/af_netlink.c:1329 netlink_sendmsg+0x1246/0x14d0 net/netlink/af_netlink.c:1918 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x12b6/0x1350 net/socket.c:2362 ___sys_sendmsg net/socket.c:2416 [inline] __sys_sendmsg+0x623/0x750 net/socket.c:2449 __do_sys_sendmsg net/socket.c:2458 [inline] __se_sys_sendmsg+0x97/0xb0 net/socket.c:2456 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2456 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:144 [inline] kmsan_internal_poison_shadow+0x66/0xd0 mm/kmsan/kmsan.c:127 kmsan_slab_alloc+0x8a/0xe0 mm/kmsan/kmsan_hooks.c:80 slab_alloc_node mm/slub.c:2802 [inline] __kmalloc_node_track_caller+0xb40/0x1200 mm/slub.c:4436 __kmalloc_reserve net/core/skbuff.c:142 [inline] __alloc_skb+0x2fd/0xac0 net/core/skbuff.c:210 alloc_skb include/linux/skbuff.h:1083 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1175 [inline] netlink_sendmsg+0x7d3/0x14d0 net/netlink/af_netlink.c:1893 sock_sendmsg_nosec net/socket.c:652 [inline] sock_sendmsg net/socket.c:672 [inline] ____sys_sendmsg+0x12b6/0x1350 net/socket.c:2362 ___sys_sendmsg net/socket.c:2416 [inline] __sys_sendmsg+0x623/0x750 net/socket.c:2449 __do_sys_sendmsg net/socket.c:2458 [inline] __se_sys_sendmsg+0x97/0xb0 net/socket.c:2456 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2456 do_syscall_64+0xb8/0x160 arch/x86/entry/common.c:297 entry_SYSCALL_64_after_hwframe+0x44/0xa9 ===================================================== --- This bug is generated by a bot. 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