From mboxrd@z Thu Jan 1 00:00:00 1970 From: syzbot Subject: KMSAN: uninit-value in dev_mc_add_excl Date: Fri, 26 Oct 2018 15:48:03 -0700 Message-ID: <0000000000001ee1930579298398@google.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8"; format=flowed; delsp=yes To: davem@davemloft.net, edumazet@google.com, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, sunlw.fnst@cn.fujitsu.com, syzkaller-bugs@googlegroups.com Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Hello, syzbot found the following crash on: HEAD commit: 4bb25354f0b0 kmsan: unpoison pt_regs in do_nmi() git tree: https://github.com/google/kmsan.git/master console output: https://syzkaller.appspot.com/x/log.txt?x=11e4ae95400000 kernel config: https://syzkaller.appspot.com/x/.config?x=36c582b1a617b1e6 dashboard link: https://syzkaller.appspot.com/bug?extid=d53ab4e92a1db04110ff compiler: clang version 8.0.0 (trunk 339414) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15ac7c79400000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15dbbf0d400000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+d53ab4e92a1db04110ff@syzkaller.appspotmail.com sshd (6129) used greatest stack depth: 53504 bytes left ================================================================== BUG: KMSAN: uninit-value in memcmp+0x117/0x180 lib/string.c:863 CPU: 1 PID: 6214 Comm: syz-executor693 Not tainted 4.19.0-rc8+ #70 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+0x306/0x460 lib/dump_stack.c:113 kmsan_report+0x1a2/0x2e0 mm/kmsan/kmsan.c:917 __msan_warning+0x7c/0xe0 mm/kmsan/kmsan_instr.c:500 memcmp+0x117/0x180 lib/string.c:863 dev_mc_add_excl+0x165/0x770 net/core/dev_addr_lists.c:648 ndo_dflt_fdb_add net/core/rtnetlink.c:3469 [inline] rtnl_fdb_add+0xe83/0x12a0 net/core/rtnetlink.c:3562 rtnetlink_rcv_msg+0xa53/0x1590 net/core/rtnetlink.c:4730 netlink_rcv_skb+0x394/0x640 net/netlink/af_netlink.c:2454 rtnetlink_rcv+0x50/0x60 net/core/rtnetlink.c:4748 netlink_unicast_kernel net/netlink/af_netlink.c:1317 [inline] netlink_unicast+0x166d/0x1720 net/netlink/af_netlink.c:1343 netlink_sendmsg+0x1391/0x1420 net/netlink/af_netlink.c:1908 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg net/socket.c:631 [inline] ___sys_sendmsg+0xe47/0x1200 net/socket.c:2116 __sys_sendmsg net/socket.c:2154 [inline] __do_sys_sendmsg net/socket.c:2163 [inline] __se_sys_sendmsg+0x307/0x460 net/socket.c:2161 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2161 do_syscall_64+0xbe/0x100 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 RIP: 0033:0x440fd9 Code: e8 cc ab 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 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 bb 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007ffe833197b8 EFLAGS: 00000213 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000440fd9 RDX: 0000000000000000 RSI: 0000000020000500 RDI: 0000000000000003 RBP: 0000000000000000 R08: 00000000004002c8 R09: 00000000004002c8 R10: 00000000004002c8 R11: 0000000000000213 R12: 0000000000010c7d R13: 0000000000401fb0 R14: 0000000000000000 R15: 0000000000000000 Uninit was created at: kmsan_save_stack_with_flags mm/kmsan/kmsan.c:255 [inline] kmsan_internal_poison_shadow+0xc8/0x1d0 mm/kmsan/kmsan.c:180 kmsan_kmalloc+0xa4/0x120 mm/kmsan/kmsan_hooks.c:104 kmsan_slab_alloc+0x10/0x20 mm/kmsan/kmsan_hooks.c:113 slab_post_alloc_hook mm/slab.h:446 [inline] slab_alloc_node mm/slub.c:2727 [inline] __kmalloc_node_track_caller+0xb43/0x1400 mm/slub.c:4360 __kmalloc_reserve net/core/skbuff.c:138 [inline] __alloc_skb+0x422/0xe90 net/core/skbuff.c:206 alloc_skb include/linux/skbuff.h:996 [inline] netlink_alloc_large_skb net/netlink/af_netlink.c:1189 [inline] netlink_sendmsg+0xcaf/0x1420 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:621 [inline] sock_sendmsg net/socket.c:631 [inline] ___sys_sendmsg+0xe47/0x1200 net/socket.c:2116 __sys_sendmsg net/socket.c:2154 [inline] __do_sys_sendmsg net/socket.c:2163 [inline] __se_sys_sendmsg+0x307/0x460 net/socket.c:2161 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2161 do_syscall_64+0xbe/0x100 arch/x86/entry/common.c:291 entry_SYSCALL_64_after_hwframe+0x63/0xe7 ================================================================== --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with syzbot. syzbot can test patches for this bug, for details see: https://goo.gl/tpsmEJ#testing-patches