diff mbox series

[net,2/2] net: Fix gso_features_check to check for both dev->gso_{ipv4_,}max_size

Message ID 20240923212242.15669-2-daniel@iogearbox.net (mailing list archive)
State New
Delegated to: Netdev Maintainers
Headers show
Series [net,1/2] net: Add netif_get_gro_max_size helper for GRO | expand

Checks

Context Check Description
netdev/series_format success Single patches do not need cover letters
netdev/tree_selection success Clearly marked for net, async
netdev/ynl success Generated files up to date; no warnings/errors; no diff in generated;
netdev/fixes_present success Fixes tag present in non-next series
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 54 this patch: 54
netdev/build_tools success Errors and warnings before: 0 this patch: 0
netdev/cc_maintainers fail 2 blamed authors not CCed: pabeni@redhat.com edumazet@google.com; 3 maintainers not CCed: pabeni@redhat.com kuba@kernel.org edumazet@google.com
netdev/build_clang success Errors and warnings before: 103 this patch: 103
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/deprecated_api success None detected
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: 4058 this patch: 4058
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 23 lines checked
netdev/build_clang_rust success No Rust files in patch. Skipping build
netdev/kdoc success Errors and warnings before: 101 this patch: 101
netdev/source_inline success Was 0 now: 0
netdev/contest pending net-next-2024-09-24--00-00 (tests: 0)

Commit Message

Daniel Borkmann Sept. 23, 2024, 9:22 p.m. UTC 
Commit 24ab059d2ebd ("net: check dev->gso_max_size in gso_features_check()")
added a dev->gso_max_size test to gso_features_check() in order to fall
back to GSO when needed.

This was added as it was noticed that some drivers could misbehave if TSO
packets get too big. However, the check doesn't respect dev->gso_ipv4_max_size
limit. For instance, a device could be configured with BIG TCP for IPv4,
but not IPv6.

Therefore, add a netif_get_gso_max_size() equivalent to netif_get_gro_max_size()
and use the helper to respect both limits before falling back to GSO engine.

Fixes: 24ab059d2ebd ("net: check dev->gso_max_size in gso_features_check()")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
---
 include/linux/netdevice.h | 9 +++++++++
 net/core/dev.c            | 2 +-
 2 files changed, 10 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/include/linux/netdevice.h b/include/linux/netdevice.h
index d571451638de..4d20c776a4ff 100644
--- a/include/linux/netdevice.h
+++ b/include/linux/netdevice.h
@@ -5038,6 +5038,15 @@  netif_get_gro_max_size(const struct net_device *dev, const struct sk_buff *skb)
 	       READ_ONCE(dev->gro_ipv4_max_size);
 }
 
+static inline unsigned int
+netif_get_gso_max_size(const struct net_device *dev, const struct sk_buff *skb)
+{
+	/* pairs with WRITE_ONCE() in netif_set_gso(_ipv4)_max_size() */
+	return skb->protocol == htons(ETH_P_IPV6) ?
+	       READ_ONCE(dev->gso_max_size) :
+	       READ_ONCE(dev->gso_ipv4_max_size);
+}
+
 static inline bool netif_is_macsec(const struct net_device *dev)
 {
 	return dev->priv_flags & IFF_MACSEC;
diff --git a/net/core/dev.c b/net/core/dev.c
index cd479f5f22f6..74cf78a6b512 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -3512,7 +3512,7 @@  static netdev_features_t gso_features_check(const struct sk_buff *skb,
 	if (gso_segs > READ_ONCE(dev->gso_max_segs))
 		return features & ~NETIF_F_GSO_MASK;
 
-	if (unlikely(skb->len >= READ_ONCE(dev->gso_max_size)))
+	if (unlikely(skb->len >= netif_get_gso_max_size(dev, skb)))
 		return features & ~NETIF_F_GSO_MASK;
 
 	if (!skb_shinfo(skb)->gso_type) {