| Subject | Re: [PATCH 25/26] net: pass a sockptr_t into ->setsockopt | From | Eric Dumazet <> | Date | Thu, 6 Aug 2020 15:21:25 -0700 |
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On 7/22/20 11:09 PM, Christoph Hellwig wrote: > Rework the remaining setsockopt code to pass a sockptr_t instead of a > plain user pointer. This removes the last remaining set_fs(KERNEL_DS) > outside of architecture specific code. > > Signed-off-by: Christoph Hellwig <hch@lst.de> > Acked-by: Stefan Schmidt <stefan@datenfreihafen.org> [ieee802154] > ---
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> diff --git a/net/ipv6/raw.c b/net/ipv6/raw.c > index 594e01ad670aa6..874f01cd7aec42 100644 > --- a/net/ipv6/raw.c > +++ b/net/ipv6/raw.c > @@ -972,13 +972,13 @@ static int rawv6_sendmsg(struct sock *sk, struct msghdr *msg, size_t len) > } >
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> static int do_rawv6_setsockopt(struct sock *sk, int level, int optname, > - char __user *optval, unsigned int optlen) > + sockptr_t optval, unsigned int optlen) > { > struct raw6_sock *rp = raw6_sk(sk); > int val; > > - if (get_user(val, (int __user *)optval)) > + if (copy_from_sockptr(&val, optval, sizeof(val))) > return -EFAULT; >
converting get_user(...) to copy_from_sockptr(...) really assumed the optlen has been validated to be >= sizeof(int) earlier.
Which is not always the case, for example here.
User application can fool us passing optlen=0, and a user pointer of exactly TASK_SIZE-1
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