syzbot

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BUG: KMSAN: uninit-value in memchr+0xce/0x110 lib/string.c:981
CPU: 1 PID: 11290 Comm: syz-executor861 Not tainted 5.1.0+ #1
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+0x162/0x2d0 mm/kmsan/kmsan.c:623
 __msan_warning+0x75/0xe0 mm/kmsan/kmsan_instr.c:310
 memchr+0xce/0x110 lib/string.c:981
 string_is_valid net/tipc/netlink_compat.c:176 [inline]
 tipc_nl_compat_link_reset_stats+0x2a1/0x480 net/tipc/netlink_compat.c:819
 __tipc_nl_compat_doit net/tipc/netlink_compat.c:327 [inline]
 tipc_nl_compat_doit+0x3ac/0xb00 net/tipc/netlink_compat.c:360
 tipc_nl_compat_handle net/tipc/netlink_compat.c:1178 [inline]
 tipc_nl_compat_recv+0x1b1b/0x27b0 net/tipc/netlink_compat.c:1281
 genl_family_rcv_msg net/netlink/genetlink.c:602 [inline]
 genl_rcv_msg+0x185a/0x1a40 net/netlink/genetlink.c:627
 netlink_rcv_skb+0x431/0x620 net/netlink/af_netlink.c:2486
 genl_rcv+0x63/0x80 net/netlink/genetlink.c:638
 netlink_unicast_kernel net/netlink/af_netlink.c:1311 [inline]
 netlink_unicast+0xf3e/0x1020 net/netlink/af_netlink.c:1337
 netlink_sendmsg+0x127e/0x12f0 net/netlink/af_netlink.c:1926
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:661 [inline]
 ___sys_sendmsg+0xcc6/0x1200 net/socket.c:2260
 __sys_sendmsg net/socket.c:2298 [inline]
 __do_sys_sendmsg net/socket.c:2307 [inline]
 __se_sys_sendmsg+0x305/0x460 net/socket.c:2305
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2305
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x444199
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 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 1b d8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffdfa9d80c8 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00000000004002e0 RCX: 0000000000444199
RDX: 0000000000000000 RSI: 0000000020000200 RDI: 0000000000000003
RBP: 00000000006ce018 R08: 0000000000000000 R09: 00000000004002e0
R10: 0000000000001400 R11: 0000000000000246 R12: 0000000000401e40
R13: 0000000000401ed0 R14: 0000000000000000 R15: 0000000000000000

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:206 [inline]
 kmsan_internal_poison_shadow+0x92/0x150 mm/kmsan/kmsan.c:160
 kmsan_kmalloc+0xa4/0x130 mm/kmsan/kmsan_hooks.c:177
 kmsan_slab_alloc+0xe/0x10 mm/kmsan/kmsan_hooks.c:186
 slab_post_alloc_hook mm/slab.h:442 [inline]
 slab_alloc_node mm/slub.c:2771 [inline]
 __kmalloc_node_track_caller+0xcba/0xf30 mm/slub.c:4399
 __kmalloc_reserve net/core/skbuff.c:140 [inline]
 __alloc_skb+0x306/0xa10 net/core/skbuff.c:208
 alloc_skb include/linux/skbuff.h:1059 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1183 [inline]
 netlink_sendmsg+0xb81/0x12f0 net/netlink/af_netlink.c:1901
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:661 [inline]
 ___sys_sendmsg+0xcc6/0x1200 net/socket.c:2260
 __sys_sendmsg net/socket.c:2298 [inline]
 __do_sys_sendmsg net/socket.c:2307 [inline]
 __se_sys_sendmsg+0x305/0x460 net/socket.c:2305
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2305
 do_syscall_64+0xbc/0xf0 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
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