Messages in this thread Patch in this message | | | From | Eric Dumazet <> | Date | Mon, 27 Jun 2022 11:01:07 +0200 | Subject | Re: [PATCH v2] ipv6/sit: fix ipip6_tunnel_get_prl when memory allocation fails |
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On Sat, Jun 25, 2022 at 7:45 AM <zys.zljxml@gmail.com> wrote: > > From: katrinzhou <katrinzhou@tencent.com> > > Fix an illegal copy_to_user() attempt when the system fails to > allocate memory for prl due to a lack of memory.
I do not really see an illegal copy_to_user()
c = 0 -> len = 0
if ((len && copy_to_user(a + 1, kp, len)) || put_user(len, &a->datalen))
So the copy_to_user() should not be called ?
I think you should only mention that after this patch, correct error code is returned (-ENOMEM)
> > Addresses-Coverity: ("Unused value") > Fixes: 300aaeeaab5f ("[IPV6] SIT: Add SIOCGETPRL ioctl to get/dump PRL.") > Signed-off-by: katrinzhou <katrinzhou@tencent.com> > --- > > Changes in v2: > - Move the position of label "out" > > net/ipv6/sit.c | 7 +++---- > 1 file changed, 3 insertions(+), 4 deletions(-) > > diff --git a/net/ipv6/sit.c b/net/ipv6/sit.c > index c0b138c20992..3330882c0f94 100644 > --- a/net/ipv6/sit.c > +++ b/net/ipv6/sit.c > @@ -323,8 +323,6 @@ static int ipip6_tunnel_get_prl(struct net_device *dev, struct ip_tunnel_prl __u > kcalloc(cmax, sizeof(*kp), GFP_KERNEL_ACCOUNT | __GFP_NOWARN) : > NULL; > > - rcu_read_lock(); > - > ca = min(t->prl_count, cmax); > > if (!kp) { > @@ -342,6 +340,7 @@ static int ipip6_tunnel_get_prl(struct net_device *dev, struct ip_tunnel_prl __u > } > > c = 0; > + rcu_read_lock(); > for_each_prl_rcu(t->prl) { > if (c >= cmax) > break; > @@ -353,7 +352,7 @@ static int ipip6_tunnel_get_prl(struct net_device *dev, struct ip_tunnel_prl __u > if (kprl.addr != htonl(INADDR_ANY)) > break; > } > -out: > + > rcu_read_unlock(); > > len = sizeof(*kp) * c; > @@ -362,7 +361,7 @@ static int ipip6_tunnel_get_prl(struct net_device *dev, struct ip_tunnel_prl __u > ret = -EFAULT; > > kfree(kp); > - > +out: > return ret; > } > > -- > 2.27.0 >
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