• Miaohe Lin's avatar
    net: sit: fix UBSAN Undefined behaviour in check_6rd · 7cfb97ba
    Miaohe Lin authored
    [ Upstream commit a843dc4e ]
    
    In func check_6rd,tunnel->ip6rd.relay_prefixlen may equal to
    32,so UBSAN complain about it.
    
    UBSAN: Undefined behaviour in net/ipv6/sit.c:781:47
    shift exponent 32 is too large for 32-bit type 'unsigned int'
    CPU: 6 PID: 20036 Comm: syz-executor.0 Not tainted 4.19.27 #2
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1
    04/01/2014
    Call Trace:
    __dump_stack lib/dump_stack.c:77 [inline]
    dump_stack+0xca/0x13e lib/dump_stack.c:113
    ubsan_epilogue+0xe/0x81 lib/ubsan.c:159
    __ubsan_handle_shift_out_of_bounds+0x293/0x2e8 lib/ubsan.c:425
    check_6rd.constprop.9+0x433/0x4e0 net/ipv6/sit.c:781
    try_6rd net/ipv6/sit.c:806 [inline]
    ipip6_tunnel_xmit net/ipv6/sit.c:866 [inline]
    sit_tunnel_xmit+0x141c/0x2720 net/ipv6/sit.c:1033
    __netdev_start_xmit include/linux/netdevice.h:4300 [inline]
    netdev_start_xmit include/linux/netdevice.h:4309 [inline]
    xmit_one net/core/dev.c:3243 [inline]
    dev_hard_start_xmit+0x17c/0x780 net/core/dev.c:3259
    __dev_queue_xmit+0x1656/0x2500 net/core/dev.c:3829
    neigh_output include/net/neighbour.h:501 [inline]
    ip6_finish_output2+0xa36/0x2290 net/ipv6/ip6_output.c:120
    ip6_finish_output+0x3e7/0xa20 net/ipv6/ip6_output.c:154
    NF_HOOK_COND include/linux/netfilter.h:278 [inline]
    ip6_output+0x1e2/0x720 net/ipv6/ip6_output.c:171
    dst_output include/net/dst.h:444 [inline]
    ip6_local_out+0x99/0x170 net/ipv6/output_core.c:176
    ip6_send_skb+0x9d/0x2f0 net/ipv6/ip6_output.c:1697
    ip6_push_pending_frames+0xc0/0x100 net/ipv6/ip6_output.c:1717
    rawv6_push_pending_frames net/ipv6/raw.c:616 [inline]
    rawv6_sendmsg+0x2435/0x3530 net/ipv6/raw.c:946
    inet_sendmsg+0xf8/0x5c0 net/ipv4/af_inet.c:798
    sock_sendmsg_nosec net/socket.c:621 [inline]
    sock_sendmsg+0xc8/0x110 net/socket.c:631
    ___sys_sendmsg+0x6cf/0x890 net/socket.c:2114
    __sys_sendmsg+0xf0/0x1b0 net/socket.c:2152
    do_syscall_64+0xc8/0x580 arch/x86/entry/common.c:290
    entry_SYSCALL_64_after_hwframe+0x49/0xbe
    Signed-off-by: default avatarlinmiaohe <linmiaohe@huawei.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    7cfb97ba
sit.c 45.6 KB