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| author | Eric Dumazet <edumazet@google.com> | 2024-05-06 10:28:12 +0000 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2024-05-07 16:19:14 -0700 |
| commit | 1eb2cded45b35816085c1f962933c187d970f9dc (patch) | |
| tree | 27a26692748d3c69fcd896a10db9bc89c1eb54b5 /net/ipv4 | |
| parent | feb8c2b76eb3fae59a1f62451508c98c36db5e3a (diff) | |
| download | linux-stable-1eb2cded45b35816085c1f962933c187d970f9dc.tar.gz linux-stable-1eb2cded45b35816085c1f962933c187d970f9dc.tar.bz2 linux-stable-1eb2cded45b35816085c1f962933c187d970f9dc.zip | |
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')
| -rw-r--r-- | net/ipv4/ip_gre.c | 2 | ||||
| -rw-r--r-- | net/ipv4/ip_tunnel.c | 4 |
2 files changed, 3 insertions, 3 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) && diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index f1c5f6c3f2f8..bccef2fcf620 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -897,7 +897,7 @@ static void ip_tunnel_update(struct ip_tunnel_net *itn, t->fwmark = fwmark; mtu = ip_tunnel_bind_dev(dev); if (set_mtu) - dev->mtu = mtu; + WRITE_ONCE(dev->mtu, mtu); } dst_cache_reset(&t->dst_cache); netdev_state_change(dev); @@ -1082,7 +1082,7 @@ int __ip_tunnel_change_mtu(struct net_device *dev, int new_mtu, bool strict) new_mtu = max_mtu; } - dev->mtu = new_mtu; + WRITE_ONCE(dev->mtu, new_mtu); return 0; } EXPORT_SYMBOL_GPL(__ip_tunnel_change_mtu); |