On Mon, Jul 20, 2020 at 2:25 AM syzbot <syzbot+721b564cd88ebb710182@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > syzbot has found a reproducer for the following issue on: > > HEAD commit: 14525656 compiler.h: reinstate missing KMSAN_INIT > git tree: https://github.com/google/kmsan.git master > console output: https://syzkaller.appspot.com/x/log.txt?x=16a7c827100000 > kernel config: https://syzkaller.appspot.com/x/.config?x=c534a9fad6323722 > dashboard link: https://syzkaller.appspot.com/bug?extid=721b564cd88ebb710182 > compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=115be9d7100000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15b9425f100000 > > IMPORTANT: if you fix the issue, please add the following tag to the commit: > Reported-by: syzbot+721b564cd88ebb710182@xxxxxxxxxxxxxxxxxxxxxxxxx Sorry for the noise. This is a false report caused by incorrect copy_to_user() instrumentation after KMSAN rebase. Should be fixed now. #syz invalid > ===================================================== > BUG: KMSAN: uninit-value in __skb_checksum_complete+0x37f/0x540 net/core/skbuff.c:2850 > CPU: 1 PID: 8457 Comm: syz-executor769 Not tainted 5.8.0-rc5-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+0x1df/0x240 lib/dump_stack.c:118 > kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121 > __msan_warning+0x58/0xa0 mm/kmsan/kmsan_instr.c:215 > __skb_checksum_complete+0x37f/0x540 net/core/skbuff.c:2850 > nf_ip_checksum+0x53b/0x740 net/netfilter/utils.c:36 > nf_nat_icmp_reply_translation+0x2ba/0x980 net/netfilter/nf_nat_proto.c:578 > nf_nat_ipv4_fn net/netfilter/nf_nat_proto.c:637 [inline] > nf_nat_ipv4_local_fn+0x215/0x830 net/netfilter/nf_nat_proto.c:708 > nf_hook_entry_hookfn include/linux/netfilter.h:135 [inline] > nf_hook_slow+0x16e/0x400 net/netfilter/core.c:512 > nf_hook include/linux/netfilter.h:262 [inline] > __ip_local_out+0x69b/0x800 net/ipv4/ip_output.c:114 > ip_local_out net/ipv4/ip_output.c:123 [inline] > ip_send_skb net/ipv4/ip_output.c:1560 [inline] > ip_push_pending_frames+0x16f/0x460 net/ipv4/ip_output.c:1580 > icmp_push_reply+0x660/0x710 net/ipv4/icmp.c:390 > __icmp_send+0x23ca/0x3150 net/ipv4/icmp.c:740 > icmp_send include/net/icmp.h:43 [inline] > ip_fragment+0x39f/0x400 net/ipv4/ip_output.c:579 > __ip_finish_output+0xd34/0xd80 net/ipv4/ip_output.c:304 > ip_finish_output+0x166/0x410 net/ipv4/ip_output.c:316 > NF_HOOK_COND include/linux/netfilter.h:296 [inline] > ip_output+0x593/0x680 net/ipv4/ip_output.c:430 > dst_output include/net/dst.h:443 [inline] > ip_local_out net/ipv4/ip_output.c:125 [inline] > __ip_queue_xmit+0x1b5c/0x21a0 net/ipv4/ip_output.c:530 > ip_queue_xmit include/net/ip.h:237 [inline] > l2tp_ip_sendmsg+0x1477/0x1870 net/l2tp/l2tp_ip.c:508 > inet_sendmsg+0x2d8/0x2e0 net/ipv4/af_inet.c:814 > sock_sendmsg_nosec net/socket.c:652 [inline] > sock_sendmsg net/socket.c:672 [inline] > kernel_sendmsg+0x384/0x440 net/socket.c:692 > sock_no_sendpage+0x235/0x300 net/core/sock.c:2853 > kernel_sendpage net/socket.c:3642 [inline] > sock_sendpage+0x1e1/0x2c0 net/socket.c:945 > pipe_to_sendpage+0x38c/0x4c0 fs/splice.c:448 > splice_from_pipe_feed fs/splice.c:502 [inline] > __splice_from_pipe+0x565/0xf00 fs/splice.c:626 > splice_from_pipe fs/splice.c:661 [inline] > generic_splice_sendpage+0x1d5/0x2d0 fs/splice.c:834 > do_splice_from fs/splice.c:846 [inline] > direct_splice_actor+0x1fd/0x580 fs/splice.c:1016 > splice_direct_to_actor+0x6b2/0xf50 fs/splice.c:971 > do_splice_direct+0x342/0x580 fs/splice.c:1059 > do_sendfile+0x101b/0x1d40 fs/read_write.c:1540 > __do_sys_sendfile64 fs/read_write.c:1601 [inline] > __se_sys_sendfile64+0x2bb/0x360 fs/read_write.c:1587 > __x64_sys_sendfile64+0x56/0x70 fs/read_write.c:1587 > do_syscall_64+0xb0/0x150 arch/x86/entry/common.c:386 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > RIP: 0033:0x440409 > Code: Bad RIP value. > RSP: 002b:00007ffe9c5d76d8 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 > RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440409 > RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000003 > RBP: 00000000006cb018 R08: 0000000000000014 R09: 65732f636f72702f > R10: 0800000080004103 R11: 0000000000000246 R12: 0000000000401c70 > R13: 0000000000401d00 R14: 0000000000000000 R15: 0000000000000000 > > 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 > csum_partial_copy+0xae/0x100 lib/checksum.c:154 > skb_copy_and_csum_bits+0x227/0x1130 net/core/skbuff.c:2737 > icmp_glue_bits+0x166/0x380 net/ipv4/icmp.c:353 > __ip_append_data+0x47c4/0x5630 net/ipv4/ip_output.c:1131 > ip_append_data+0x328/0x480 net/ipv4/ip_output.c:1315 > icmp_push_reply+0x206/0x710 net/ipv4/icmp.c:371 > __icmp_send+0x23ca/0x3150 net/ipv4/icmp.c:740 > icmp_send include/net/icmp.h:43 [inline] > ip_fragment+0x39f/0x400 net/ipv4/ip_output.c:579 > __ip_finish_output+0xd34/0xd80 net/ipv4/ip_output.c:304 > ip_finish_output+0x166/0x410 net/ipv4/ip_output.c:316 > NF_HOOK_COND include/linux/netfilter.h:296 [inline] > ip_output+0x593/0x680 net/ipv4/ip_output.c:430 > dst_output include/net/dst.h:443 [inline] > ip_local_out net/ipv4/ip_output.c:125 [inline] > __ip_queue_xmit+0x1b5c/0x21a0 net/ipv4/ip_output.c:530 > ip_queue_xmit include/net/ip.h:237 [inline] > l2tp_ip_sendmsg+0x1477/0x1870 net/l2tp/l2tp_ip.c:508 > inet_sendmsg+0x2d8/0x2e0 net/ipv4/af_inet.c:814 > sock_sendmsg_nosec net/socket.c:652 [inline] > sock_sendmsg net/socket.c:672 [inline] > kernel_sendmsg+0x384/0x440 net/socket.c:692 > sock_no_sendpage+0x235/0x300 net/core/sock.c:2853 > kernel_sendpage net/socket.c:3642 [inline] > sock_sendpage+0x1e1/0x2c0 net/socket.c:945 > pipe_to_sendpage+0x38c/0x4c0 fs/splice.c:448 > splice_from_pipe_feed fs/splice.c:502 [inline] > __splice_from_pipe+0x565/0xf00 fs/splice.c:626 > splice_from_pipe fs/splice.c:661 [inline] > generic_splice_sendpage+0x1d5/0x2d0 fs/splice.c:834 > do_splice_from fs/splice.c:846 [inline] > direct_splice_actor+0x1fd/0x580 fs/splice.c:1016 > splice_direct_to_actor+0x6b2/0xf50 fs/splice.c:971 > do_splice_direct+0x342/0x580 fs/splice.c:1059 > do_sendfile+0x101b/0x1d40 fs/read_write.c:1540 > __do_sys_sendfile64 fs/read_write.c:1601 [inline] > __se_sys_sendfile64+0x2bb/0x360 fs/read_write.c:1587 > __x64_sys_sendfile64+0x56/0x70 fs/read_write.c:1587 > do_syscall_64+0xb0/0x150 arch/x86/entry/common.c:386 > 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 > _copy_from_iter_full+0xbfe/0x13b0 lib/iov_iter.c:793 > copy_from_iter_full include/linux/uio.h:156 [inline] > memcpy_from_msg include/linux/skbuff.h:3566 [inline] > l2tp_ip_sendmsg+0x6a5/0x1870 net/l2tp/l2tp_ip.c:462 > inet_sendmsg+0x2d8/0x2e0 net/ipv4/af_inet.c:814 > sock_sendmsg_nosec net/socket.c:652 [inline] > sock_sendmsg net/socket.c:672 [inline] > kernel_sendmsg+0x384/0x440 net/socket.c:692 > sock_no_sendpage+0x235/0x300 net/core/sock.c:2853 > kernel_sendpage net/socket.c:3642 [inline] > sock_sendpage+0x1e1/0x2c0 net/socket.c:945 > pipe_to_sendpage+0x38c/0x4c0 fs/splice.c:448 > splice_from_pipe_feed fs/splice.c:502 [inline] > __splice_from_pipe+0x565/0xf00 fs/splice.c:626 > splice_from_pipe fs/splice.c:661 [inline] > generic_splice_sendpage+0x1d5/0x2d0 fs/splice.c:834 > do_splice_from fs/splice.c:846 [inline] > direct_splice_actor+0x1fd/0x580 fs/splice.c:1016 > splice_direct_to_actor+0x6b2/0xf50 fs/splice.c:971 > do_splice_direct+0x342/0x580 fs/splice.c:1059 > do_sendfile+0x101b/0x1d40 fs/read_write.c:1540 > __do_sys_sendfile64 fs/read_write.c:1601 [inline] > __se_sys_sendfile64+0x2bb/0x360 fs/read_write.c:1587 > __x64_sys_sendfile64+0x56/0x70 fs/read_write.c:1587 > do_syscall_64+0xb0/0x150 arch/x86/entry/common.c:386 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > Uninit was created at: > kmsan_save_stack_with_flags+0x3c/0x90 mm/kmsan/kmsan.c:144 > kmsan_internal_alloc_meta_for_pages mm/kmsan/kmsan_shadow.c:269 [inline] > kmsan_alloc_page+0xb9/0x180 mm/kmsan/kmsan_shadow.c:293 > __alloc_pages_nodemask+0x56a2/0x5dc0 mm/page_alloc.c:4889 > alloc_pages_current+0x672/0x990 mm/mempolicy.c:2292 > alloc_pages include/linux/gfp.h:545 [inline] > push_pipe+0x605/0xb70 lib/iov_iter.c:537 > __pipe_get_pages lib/iov_iter.c:1278 [inline] > pipe_get_pages_alloc lib/iov_iter.c:1385 [inline] > iov_iter_get_pages_alloc+0x18a9/0x21c0 lib/iov_iter.c:1403 > default_file_splice_read fs/splice.c:385 [inline] > do_splice_to+0x4fc/0x14f0 fs/splice.c:871 > splice_direct_to_actor+0x45c/0xf50 fs/splice.c:950 > do_splice_direct+0x342/0x580 fs/splice.c:1059 > do_sendfile+0x101b/0x1d40 fs/read_write.c:1540 > __do_sys_sendfile64 fs/read_write.c:1601 [inline] > __se_sys_sendfile64+0x2bb/0x360 fs/read_write.c:1587 > __x64_sys_sendfile64+0x56/0x70 fs/read_write.c:1587 > do_syscall_64+0xb0/0x150 arch/x86/entry/common.c:386 > entry_SYSCALL_64_after_hwframe+0x44/0xa9 > ===================================================== > -- Alexander Potapenko Software Engineer Google Germany GmbH Erika-Mann-Straße, 33 80636 München Geschäftsführer: Paul Manicle, Halimah DeLaine Prado Registergericht und -nummer: Hamburg, HRB 86891 Sitz der Gesellschaft: Hamburg
