net/ipv4/igmp: Use struct_size() helper

Replace IP_SFLSIZE() with struct_size() helper in order to avoid any
potential type mistakes or integer overflows that, in the worst
scenario, could lead to heap overflows.

Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Gustavo A. R. Silva 2021-08-04 16:18:50 -05:00 committed by David S. Miller
parent db243b7964
commit e6a1f7e0b0
2 changed files with 13 additions and 10 deletions

View File

@ -41,9 +41,6 @@ struct ip_sf_socklist {
__be32 sl_addr[];
};
#define IP_SFLSIZE(count) (sizeof(struct ip_sf_socklist) + \
(count) * sizeof(__be32))
#define IP_SFBLOCK 10 /* allocate this many at once */
/* ip_mc_socklist is real list now. Speed is not argument;

View File

@ -2233,7 +2233,7 @@ static int ip_mc_leave_src(struct sock *sk, struct ip_mc_socklist *iml,
iml->sfmode, psf->sl_count, psf->sl_addr, 0);
RCU_INIT_POINTER(iml->sflist, NULL);
/* decrease mem now to avoid the memleak warning */
atomic_sub(IP_SFLSIZE(psf->sl_max), &sk->sk_omem_alloc);
atomic_sub(struct_size(psf, sl_addr, psf->sl_max), &sk->sk_omem_alloc);
kfree_rcu(psf, rcu);
return err;
}
@ -2382,7 +2382,8 @@ int ip_mc_source(int add, int omode, struct sock *sk, struct
if (psl)
count += psl->sl_max;
newpsl = sock_kmalloc(sk, IP_SFLSIZE(count), GFP_KERNEL);
newpsl = sock_kmalloc(sk, struct_size(newpsl, sl_addr, count),
GFP_KERNEL);
if (!newpsl) {
err = -ENOBUFS;
goto done;
@ -2393,7 +2394,8 @@ int ip_mc_source(int add, int omode, struct sock *sk, struct
for (i = 0; i < psl->sl_count; i++)
newpsl->sl_addr[i] = psl->sl_addr[i];
/* decrease mem now to avoid the memleak warning */
atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc);
atomic_sub(struct_size(psl, sl_addr, psl->sl_max),
&sk->sk_omem_alloc);
kfree_rcu(psl, rcu);
}
rcu_assign_pointer(pmc->sflist, newpsl);
@ -2468,8 +2470,9 @@ int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
goto done;
}
if (msf->imsf_numsrc) {
newpsl = sock_kmalloc(sk, IP_SFLSIZE(msf->imsf_numsrc),
GFP_KERNEL);
newpsl = sock_kmalloc(sk, struct_size(newpsl, sl_addr,
msf->imsf_numsrc),
GFP_KERNEL);
if (!newpsl) {
err = -ENOBUFS;
goto done;
@ -2480,7 +2483,9 @@ int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
err = ip_mc_add_src(in_dev, &msf->imsf_multiaddr,
msf->imsf_fmode, newpsl->sl_count, newpsl->sl_addr, 0);
if (err) {
sock_kfree_s(sk, newpsl, IP_SFLSIZE(newpsl->sl_max));
sock_kfree_s(sk, newpsl,
struct_size(newpsl, sl_addr,
newpsl->sl_max));
goto done;
}
} else {
@ -2493,7 +2498,8 @@ int ip_mc_msfilter(struct sock *sk, struct ip_msfilter *msf, int ifindex)
(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,
psl->sl_count, psl->sl_addr, 0);
/* decrease mem now to avoid the memleak warning */
atomic_sub(IP_SFLSIZE(psl->sl_max), &sk->sk_omem_alloc);
atomic_sub(struct_size(psl, sl_addr, psl->sl_max),
&sk->sk_omem_alloc);
kfree_rcu(psl, rcu);
} else
(void) ip_mc_del_src(in_dev, &msf->imsf_multiaddr, pmc->sfmode,