diff mbox series

[v1,net,03/15] igmp: Fix data-races around sysctl_igmp_max_msf.

Message ID 20220715171755.38497-4-kuniyu@amazon.com (mailing list archive)
State Accepted
Commit 6ae0f2e553737b8cce49a1372573c81130ffa80e
Delegated to: Netdev Maintainers
Headers show
Series sysctl: Fix data-races around ipv4_net_table (Round 3). | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net, async
netdev/fixes_present success Fixes tag present in non-next series
netdev/subject_prefix success Link
netdev/cover_letter success Series has a cover letter
netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 6 this patch: 6
netdev/cc_maintainers warning 1 maintainers not CCed: yoshfuji@linux-ipv6.org
netdev/build_clang success Errors and warnings before: 6 this patch: 6
netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success Fixes tag looks correct
netdev/build_allmodconfig_warn success Errors and warnings before: 6 this patch: 6
netdev/checkpatch warning WARNING: line length of 82 exceeds 80 columns
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Kuniyuki Iwashima July 15, 2022, 5:17 p.m. UTC 
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>
---
 net/ipv4/igmp.c        | 2 +-
 net/ipv4/ip_sockglue.c | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 792ea1b56b9e..cd7839db34da 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 d497d525dea3..a8a323ecbb54 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);
@@ -1244,7 +1244,7 @@  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;