From: Kuniyuki Iwashima kuniyu@amazon.com
[ Upstream commit 6ae0f2e553737b8cce49a1372573c81130ffa80e ]
While reading sysctl_igmp_max_msf, it can be changed concurrently. Thus, we need to add READ_ONCE() to its readers.
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Kuniyuki Iwashima kuniyu@amazon.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- net/ipv4/igmp.c | 2 +- net/ipv4/ip_sockglue.c | 6 +++--- 2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c index 8920ae3751d1..9f4674244aff 100644 --- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c @@ -2384,7 +2384,7 @@ int ip_mc_source(int add, int omode, struct sock *sk, struct } /* else, add a new source to the filter */
- if (psl && psl->sl_count >= net->ipv4.sysctl_igmp_max_msf) { + if (psl && psl->sl_count >= READ_ONCE(net->ipv4.sysctl_igmp_max_msf)) { err = -ENOBUFS; goto done; } diff --git a/net/ipv4/ip_sockglue.c b/net/ipv4/ip_sockglue.c index 8268e427f889..38f296afb663 100644 --- a/net/ipv4/ip_sockglue.c +++ b/net/ipv4/ip_sockglue.c @@ -782,7 +782,7 @@ static int ip_set_mcast_msfilter(struct sock *sk, sockptr_t optval, int optlen) /* numsrc >= (4G-140)/128 overflow in 32 bits */ err = -ENOBUFS; if (gsf->gf_numsrc >= 0x1ffffff || - gsf->gf_numsrc > sock_net(sk)->ipv4.sysctl_igmp_max_msf) + gsf->gf_numsrc > READ_ONCE(sock_net(sk)->ipv4.sysctl_igmp_max_msf)) goto out_free_gsf;
err = -EINVAL; @@ -832,7 +832,7 @@ static int compat_ip_set_mcast_msfilter(struct sock *sk, sockptr_t optval,
/* numsrc >= (4G-140)/128 overflow in 32 bits */ err = -ENOBUFS; - if (n > sock_net(sk)->ipv4.sysctl_igmp_max_msf) + if (n > READ_ONCE(sock_net(sk)->ipv4.sysctl_igmp_max_msf)) goto out_free_gsf; err = set_mcast_msfilter(sk, gf32->gf_interface, n, gf32->gf_fmode, &gf32->gf_group, gf32->gf_slist_flex); @@ -1242,7 +1242,7 @@ static int do_ip_setsockopt(struct sock *sk, int level, int optname, } /* numsrc >= (1G-4) overflow in 32 bits */ if (msf->imsf_numsrc >= 0x3ffffffcU || - msf->imsf_numsrc > net->ipv4.sysctl_igmp_max_msf) { + msf->imsf_numsrc > READ_ONCE(net->ipv4.sysctl_igmp_max_msf)) { kfree(msf); err = -ENOBUFS; break;