diff options
| author | Eric Dumazet | 2023-09-05 04:23:38 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2023-09-13 09:42:59 +0200 |
| commit | 6678912b4df1bfac6f7c80642d56dc22e23419e4 (patch) | |
| tree | 4f3a92cf3cbd8ee6dcf1da6f14a82a5964001e1c | |
| parent | ad8900dd8a568288cf6e332ffd4f11b2e74b17f4 (diff) | |
igmp: limit igmpv3_newpack() packet size to IP_MAX_MTU
commit c3b704d4a4a265660e665df51b129e8425216ed1 upstream.
This is a follow up of commit 915d975b2ffa ("net: deal with integer
overflows in kmalloc_reserve()") based on David Laight feedback.
Back in 2010, I failed to realize malicious users could set dev->mtu
to arbitrary values. This mtu has been since limited to 0x7fffffff but
regardless of how big dev->mtu is, it makes no sense for igmpv3_newpack()
to allocate more than IP_MAX_MTU and risk various skb fields overflows.
Fixes: 57e1ab6eaddc ("igmp: refine skb allocations")
Link: https://lore.kernel.org/netdev/d273628df80f45428e739274ab9ecb72@AcuMS.aculab.com/
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: David Laight <David.Laight@ACULAB.COM>
Cc: Kyle Zeng <zengyhkyle@gmail.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | net/ipv4/igmp.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c index 81be3e0f0e70..cbc4816ed7d8 100644 --- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c @@ -353,8 +353,9 @@ static struct sk_buff *igmpv3_newpack(struct net_device *dev, unsigned int mtu) struct flowi4 fl4; int hlen = LL_RESERVED_SPACE(dev); int tlen = dev->needed_tailroom; - unsigned int size = mtu; + unsigned int size; + size = min(mtu, IP_MAX_MTU); while (1) { skb = alloc_skb(size + hlen + tlen, GFP_ATOMIC | __GFP_NOWARN); |