diff mbox series

[v1,net,06/15] icmp: Fix a data-race around sysctl_icmp_echo_ignore_broadcasts.

Message ID 20220712001533.89927-7-kuniyu@amazon.com (mailing list archive)
State Accepted
Commit 66484bb98ed2dfa1dda37a32411483d8311ac269
Delegated to: Netdev Maintainers
Headers show
Series sysctl: Fix data-races around ipv4_net_table (Round 1). | expand

Checks

Context Check Description
netdev/tree_selection success Clearly marked for net
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: 4 this patch: 4
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: 4 this patch: 4
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 16 lines checked
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/source_inline success Was 0 now: 0

Commit Message

Kuniyuki Iwashima July 12, 2022, 12:15 a.m. UTC
While reading sysctl_icmp_echo_ignore_broadcasts, it can be changed
concurrently.  Thus, we need to add READ_ONCE() to its reader.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
 net/ipv4/icmp.c            | 2 +-
 net/ipv4/sysctl_net_ipv4.c | 2 ++
 2 files changed, 3 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/ipv4/icmp.c b/net/ipv4/icmp.c
index c406e324c594..4b1d84d3feaa 100644
--- a/net/ipv4/icmp.c
+++ b/net/ipv4/icmp.c
@@ -1249,7 +1249,7 @@  int icmp_rcv(struct sk_buff *skb)
 		 */
 		if ((icmph->type == ICMP_ECHO ||
 		     icmph->type == ICMP_TIMESTAMP) &&
-		    net->ipv4.sysctl_icmp_echo_ignore_broadcasts) {
+		    READ_ONCE(net->ipv4.sysctl_icmp_echo_ignore_broadcasts)) {
 			reason = SKB_DROP_REASON_INVALID_PROTO;
 			goto error;
 		}
diff --git a/net/ipv4/sysctl_net_ipv4.c b/net/ipv4/sysctl_net_ipv4.c
index 64682a01914a..cb53476a292e 100644
--- a/net/ipv4/sysctl_net_ipv4.c
+++ b/net/ipv4/sysctl_net_ipv4.c
@@ -617,6 +617,8 @@  static struct ctl_table ipv4_net_table[] = {
 		.maxlen		= sizeof(u8),
 		.mode		= 0644,
 		.proc_handler	= proc_dou8vec_minmax,
+		.extra1		= SYSCTL_ZERO,
+		.extra2		= SYSCTL_ONE
 	},
 	{
 		.procname	= "icmp_ignore_bogus_error_responses",