diff options
| author | Eric Dumazet | 2024-05-06 10:28:12 +0000 |
|---|---|---|
| committer | Jakub Kicinski | 2024-05-07 16:19:14 -0700 |
| commit | 1eb2cded45b35816085c1f962933c187d970f9dc (patch) | |
| tree | 27a26692748d3c69fcd896a10db9bc89c1eb54b5 /net/ipv6 | |
| parent | feb8c2b76eb3fae59a1f62451508c98c36db5e3a (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/ipv6')
| -rw-r--r-- | net/ipv6/ip6_tunnel.c | 2 | ||||
| -rw-r--r-- | net/ipv6/ip6_vti.c | 3 |
2 files changed, 3 insertions, 2 deletions
diff --git a/net/ipv6/ip6_tunnel.c b/net/ipv6/ip6_tunnel.c index 5aec79c2af1a..9dee0c127955 100644 --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -1746,7 +1746,7 @@ int ip6_tnl_change_mtu(struct net_device *dev, int new_mtu) if (new_mtu > IP_MAX_MTU - dev->hard_header_len) return -EINVAL; } - dev->mtu = new_mtu; + WRITE_ONCE(dev->mtu, new_mtu); return 0; } EXPORT_SYMBOL(ip6_tnl_change_mtu); diff --git a/net/ipv6/ip6_vti.c b/net/ipv6/ip6_vti.c index 78344cf3867e..590737c27537 100644 --- a/net/ipv6/ip6_vti.c +++ b/net/ipv6/ip6_vti.c @@ -666,7 +666,8 @@ static void vti6_link_config(struct ip6_tnl *t, bool keep_mtu) dev->flags &= ~IFF_POINTOPOINT; if (keep_mtu && dev->mtu) { - dev->mtu = clamp(dev->mtu, dev->min_mtu, dev->max_mtu); + WRITE_ONCE(dev->mtu, + clamp(dev->mtu, dev->min_mtu, dev->max_mtu)); return; } |