[PATCH][next] net/ipv4: Revert use of struct_size() helper
From: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Date: 2021-08-04 18:20:53
Also in:
linux-hardening, lkml
Subsystem:
networking [general], networking [ipv4/ipv6], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, David Ahern, Ido Schimmel, Linus Torvalds
Revert the use of structr_size() and stay with IP_MSFILTER_SIZE() for
now, as in this case, the size of struct ip_msfilter didn't change with
the addition of the flexible array imsf_slist_flex[]. So, if we use
struct_size() we will be allocating and calculating the size of
struct ip_msfilter with one too many items for imsf_slist_flex[].
We might use struct_size() in the future, but for now let's stay
with IP_MSFILTER_SIZE().
Fixes: 2d3e5caf96b9 ("net/ipv4: Replace one-element array with flexible-array member")
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
---
net/ipv4/igmp.c | 4 ++--
net/ipv4/ip_sockglue.c | 12 +++++-------
2 files changed, 7 insertions(+), 9 deletions(-)
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index a5f4ecb02e97..c2d477eb6825 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c@@ -2553,8 +2553,8 @@ int ip_mc_msfget(struct sock *sk, struct ip_msfilter *msf, copycount = count < msf->imsf_numsrc ? count : msf->imsf_numsrc; len = flex_array_size(psl, sl_addr, copycount); msf->imsf_numsrc = count; - if (put_user(struct_size(optval, imsf_slist_flex, copycount), optlen) || - copy_to_user(optval, msf, struct_size(optval, imsf_slist_flex, 0))) { + if (put_user(IP_MSFILTER_SIZE(copycount), optlen) || + copy_to_user(optval, msf, IP_MSFILTER_SIZE(0))) { return -EFAULT; } if (len &&
diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c
index bbe660b84a91..468969c75708 100644
--- a/net/ipv4/ip_sockglue.c
+++ b/net/ipv4/ip_sockglue.c@@ -667,7 +667,7 @@ static int set_mcast_msfilter(struct sock *sk, int ifindex, struct sockaddr_in *psin; int err, i; - msf = kmalloc(struct_size(msf, imsf_slist_flex, numsrc), GFP_KERNEL); + msf = kmalloc(IP_MSFILTER_SIZE(numsrc), GFP_KERNEL); if (!msf) return -ENOBUFS;
@@ -1228,7 +1228,7 @@ static int do_ip_setsockopt(struct sock *sk, int level, int optname, { struct ip_msfilter *msf; - if (optlen < struct_size(msf, imsf_slist_flex, 0)) + if (optlen < IP_MSFILTER_SIZE(0)) goto e_inval; if (optlen > sysctl_optmem_max) { err = -ENOBUFS;
@@ -1246,8 +1246,7 @@ static int do_ip_setsockopt(struct sock *sk, int level, int optname, err = -ENOBUFS; break; } - if (struct_size(msf, imsf_slist_flex, msf->imsf_numsrc) > - optlen) { + if (IP_MSFILTER_SIZE(msf->imsf_numsrc) > optlen) { kfree(msf); err = -EINVAL; break;
@@ -1660,12 +1659,11 @@ static int do_ip_getsockopt(struct sock *sk, int level, int optname, { struct ip_msfilter msf; - if (len < struct_size(&msf, imsf_slist_flex, 0)) { + if (len < IP_MSFILTER_SIZE(0)) { err = -EINVAL; goto out; } - if (copy_from_user(&msf, optval, - struct_size(&msf, imsf_slist_flex, 0))) { + if (copy_from_user(&msf, optval, IP_MSFILTER_SIZE(0))) { err = -EFAULT; goto out; }
--
2.27.0