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| author | Eric Dumazet <edumazet@google.com> | 2023-09-05 07:23:38 +0300 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2023-09-05 19:49:40 +0300 |
| commit | c3b704d4a4a265660e665df51b129e8425216ed1 (patch) | |
| tree | cf8d488ca7e6e0133504e5137a218d87436d5c22 /net | |
| parent | d3287e4038ca4f81e02067ab72d087af7224c68b (diff) | |
| download | linux-c3b704d4a4a265660e665df51b129e8425216ed1.tar.xz | |
igmp: limit igmpv3_newpack() packet size to IP_MAX_MTU
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>
Diffstat (limited to 'net')
| -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 0c9e768e5628..418e5fb58fd3 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); |