From: "Gustavo A. R. Silva" <gustavoars@kernel.org>
To: "David S. Miller" <davem@davemloft.net>,
Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
David Ahern <dsahern@kernel.org>,
Jakub Kicinski <kuba@kernel.org>
Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
"Gustavo A. R. Silva" <gustavoars@kernel.org>,
linux-hardening@vger.kernel.org
Subject: [PATCH][next] net/ipv4/igmp: Use struct_size() helper
Date: Wed, 4 Aug 2021 16:18:50 -0500 [thread overview]
Message-ID: <20210804211850.GA42046@embeddedor> (raw)
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>
---
include/linux/igmp.h | 3 ---
net/ipv4/igmp.c | 20 +++++++++++++-------
2 files changed, 13 insertions(+), 10 deletions(-)
diff --git a/include/linux/igmp.h b/include/linux/igmp.h
index 64ce8cd1cfaf..93c262ecbdc9 100644
--- a/include/linux/igmp.h
+++ b/include/linux/igmp.h
@@ -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;
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index a5f4ecb02e97..cca84d2b13d6 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -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,
--
2.27.0
reply other threads:[~2021-08-04 21:16 UTC|newest]
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