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Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , "Michael S. Tsirkin" , Xuan Zhuo , Shuah Khan , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-kselftest@vger.kernel.org, Yuri Benditovich , Andrew Melnychenko , Stephen Hemminger , gur.stavi@huawei.com, devel@daynix.com, Akihiko Odaki Cc: Willem de Bruijn X-Mailer: b4 0.14.2 hdr_len is repeatedly used so keep it in a local variable. Signed-off-by: Akihiko Odaki Reviewed-by: Willem de Bruijn --- drivers/net/tun.c | 24 +++++++++++------------- 1 file changed, 11 insertions(+), 13 deletions(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 452fc5104260fe7ff5fdd5cedc5d2647cbe35c79..9d4aabc3b63c8f9baab82d7ab2b= ba567e9075484 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1746,6 +1746,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, s= truct tun_file *tfile, struct virtio_net_hdr gso =3D { 0 }; int good_linear; int copylen; + int hdr_len =3D 0; bool zerocopy =3D false; int err; u32 rxhash =3D 0; @@ -1772,19 +1773,21 @@ static ssize_t tun_get_user(struct tun_struct *tun,= struct tun_file *tfile, if (!copy_from_iter_full(&gso, sizeof(gso), from)) return -EFAULT; =20 - if ((gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) && - tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, gso.csum_offse= t) + 2 > tun16_to_cpu(tun, gso.hdr_len)) - gso.hdr_len =3D cpu_to_tun16(tun, tun16_to_cpu(tun, gso.csum_start) + t= un16_to_cpu(tun, gso.csum_offset) + 2); + hdr_len =3D tun16_to_cpu(tun, gso.hdr_len); =20 - if (tun16_to_cpu(tun, gso.hdr_len) > len) + if (gso.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM) { + hdr_len =3D max(tun16_to_cpu(tun, gso.csum_start) + tun16_to_cpu(tun, g= so.csum_offset) + 2, hdr_len); + gso.hdr_len =3D cpu_to_tun16(tun, hdr_len); + } + + if (hdr_len > len) return -EINVAL; iov_iter_advance(from, vnet_hdr_sz - sizeof(gso)); } =20 if ((tun->flags & TUN_TYPE_MASK) =3D=3D IFF_TAP) { align +=3D NET_IP_ALIGN; - if (unlikely(len < ETH_HLEN || - (gso.hdr_len && tun16_to_cpu(tun, gso.hdr_len) < ETH_HLEN))) + if (unlikely(len < ETH_HLEN || (hdr_len && hdr_len < ETH_HLEN))) return -EINVAL; } =20 @@ -1797,9 +1800,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, s= truct tun_file *tfile, * enough room for skb expand head in case it is used. * The rest of the buffer is mapped from userspace. */ - copylen =3D gso.hdr_len ? tun16_to_cpu(tun, gso.hdr_len) : GOODCOPY_LEN; - if (copylen > good_linear) - copylen =3D good_linear; + copylen =3D min(hdr_len ? hdr_len : GOODCOPY_LEN, good_linear); linear =3D copylen; iov_iter_advance(&i, copylen); if (iov_iter_npages(&i, INT_MAX) <=3D MAX_SKB_FRAGS) @@ -1820,10 +1821,7 @@ static ssize_t tun_get_user(struct tun_struct *tun, = struct tun_file *tfile, } else { if (!zerocopy) { copylen =3D len; - if (tun16_to_cpu(tun, gso.hdr_len) > good_linear) - linear =3D good_linear; - else - linear =3D tun16_to_cpu(tun, gso.hdr_len); + linear =3D min(hdr_len, good_linear); } =20 if (frags) { --=20 2.48.1