diff mbox series

[v1,net,03/15] ipv4: Fix data-races around sysctl_fib_multipath_hash_fields.

Message ID 20220718172653.22111-4-kuniyu@amazon.com (mailing list archive)
State Accepted
Commit 8895a9c2ac76fb9d3922fed4fe092c8ec5e5cccc
Delegated to: Netdev Maintainers
Headers show
Series sysctl: Fix data-races around ipv4_net_table (Round 4). | 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: 3 this patch: 3
netdev/cc_maintainers warning 2 maintainers not CCed: yoshfuji@linux-ipv6.org petrm@nvidia.com
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: 3 this patch: 3
netdev/checkpatch warning WARNING: line length of 84 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 18, 2022, 5:26 p.m. UTC 
While reading sysctl_fib_multipath_hash_fields, it can be changed
concurrently.  Thus, we need to add READ_ONCE() to its readers.

Fixes: ce5c9c20d364 ("ipv4: Add a sysctl to control multipath hash fields")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
---
CC: Ido Schimmel <idosch@nvidia.com>
---
 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c | 2 +-
 net/ipv4/route.c                                      | 6 +++---
 2 files changed, 4 insertions(+), 4 deletions(-)

Comments

Ido Schimmel July 19, 2022, 9:38 a.m. UTC | #1 
On Mon, Jul 18, 2022 at 10:26:41AM -0700, Kuniyuki Iwashima wrote:
> While reading sysctl_fib_multipath_hash_fields, it can be changed
> concurrently.  Thus, we need to add READ_ONCE() to its readers.
> 
> Fixes: ce5c9c20d364 ("ipv4: Add a sysctl to control multipath hash fields")
> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
> ---
> CC: Ido Schimmel <idosch@nvidia.com>

Reviewed-by: Ido Schimmel <idosch@nvidia.com>
diff mbox series

Patch

diff --git a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
index de63a5f3b767..85aa1c468cd4 100644
--- a/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
+++ b/drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c
@@ -10342,7 +10342,7 @@  static void mlxsw_sp_mp4_hash_init(struct mlxsw_sp *mlxsw_sp,
 		mlxsw_sp_mp_hash_inner_l3(config);
 		break;
 	case 3:
-		hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields;
+		hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields);
 		/* Outer */
 		MLXSW_SP_MP_HASH_HEADER_SET(headers, IPV4_EN_NOT_TCP_NOT_UDP);
 		MLXSW_SP_MP_HASH_HEADER_SET(headers, IPV4_EN_TCP_UDP);
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index 521194dd1c99..4702c61207a8 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -1929,7 +1929,7 @@  static u32 fib_multipath_custom_hash_outer(const struct net *net,
 					   const struct sk_buff *skb,
 					   bool *p_has_inner)
 {
-	u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields;
+	u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields);
 	struct flow_keys keys, hash_keys;
 
 	if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))
@@ -1958,7 +1958,7 @@  static u32 fib_multipath_custom_hash_inner(const struct net *net,
 					   const struct sk_buff *skb,
 					   bool has_inner)
 {
-	u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields;
+	u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields);
 	struct flow_keys keys, hash_keys;
 
 	/* We assume the packet carries an encapsulation, but if none was
@@ -2018,7 +2018,7 @@  static u32 fib_multipath_custom_hash_skb(const struct net *net,
 static u32 fib_multipath_custom_hash_fl4(const struct net *net,
 					 const struct flowi4 *fl4)
 {
-	u32 hash_fields = net->ipv4.sysctl_fib_multipath_hash_fields;
+	u32 hash_fields = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_fields);
 	struct flow_keys hash_keys;
 
 	if (!(hash_fields & FIB_MULTIPATH_HASH_FIELD_OUTER_MASK))