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authorEric Dumazet <edumazet@google.com>2024-05-06 10:28:12 +0000
committerJakub Kicinski <kuba@kernel.org>2024-05-07 16:19:14 -0700
commit1eb2cded45b35816085c1f962933c187d970f9dc (patch)
tree27a26692748d3c69fcd896a10db9bc89c1eb54b5 /net/ipv4/ip_gre.c
parentfeb8c2b76eb3fae59a1f62451508c98c36db5e3a (diff)
net: annotate writes on dev->mtu from ndo_change_mtu()
Simon reported that ndo_change_mtu() methods were never updated to use WRITE_ONCE(dev->mtu, new_mtu) as hinted in commit 501a90c94510 ("inet: protect against too small mtu values.") We read dev->mtu without holding RTNL in many places, with READ_ONCE() annotations. It is time to take care of ndo_change_mtu() methods to use corresponding WRITE_ONCE() Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: Simon Horman <horms@kernel.org> Closes: https://lore.kernel.org/netdev/20240505144608.GB67882@kernel.org/ Reviewed-by: Jacob Keller <jacob.e.keller@intel.com> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Reviewed-by: Simon Horman <horms@kernel.org> Acked-by: Shannon Nelson <shannon.nelson@amd.com> Link: https://lore.kernel.org/r/20240506102812.3025432-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Diffstat (limited to 'net/ipv4/ip_gre.c')
-rw-r--r--net/ipv4/ip_gre.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index c3af965dc407..ba205473522e 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -793,7 +793,7 @@ static void ipgre_link_update(struct net_device *dev, bool set_mtu)
dev->needed_headroom += len;
if (set_mtu)
- dev->mtu = max_t(int, dev->mtu - len, 68);
+ WRITE_ONCE(dev->mtu, max_t(int, dev->mtu - len, 68));
if (test_bit(IP_TUNNEL_SEQ_BIT, tunnel->parms.o_flags) ||
(test_bit(IP_TUNNEL_CSUM_BIT, tunnel->parms.o_flags) &&