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| author | Sabrina Dubroca <[email protected]> | 2018-02-26 15:13:43 +0000 |
|---|---|---|
| committer | David S. Miller <[email protected]> | 2018-02-27 16:13:36 +0000 |
| commit | c7272c2f1229125f74f22dcdd59de9bbd804f1c8 (patch) | |
| tree | 4f70a439a495a90316a1ba294b9ddadcbf7cf292 /net/tipc/socket.c | |
| parent | Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/... (diff) | |
| download | kernel-c7272c2f1229125f74f22dcdd59de9bbd804f1c8.tar.gz kernel-c7272c2f1229125f74f22dcdd59de9bbd804f1c8.zip | |
net: ipv4: don't allow setting net.ipv4.route.min_pmtu below 68
According to RFC 1191 sections 3 and 4, ICMP frag-needed messages
indicating an MTU below 68 should be rejected:
A host MUST never reduce its estimate of the Path MTU below 68
octets.
and (talking about ICMP frag-needed's Next-Hop MTU field):
This field will never contain a value less than 68, since every
router "must be able to forward a datagram of 68 octets without
fragmentation".
Furthermore, by letting net.ipv4.route.min_pmtu be set to negative
values, we can end up with a very large PMTU when (-1) is cast into u32.
Let's also make ip_rt_min_pmtu a u32, since it's only ever compared to
unsigned ints.
Reported-by: Jianlin Shi <[email protected]>
Signed-off-by: Sabrina Dubroca <[email protected]>
Reviewed-by: Stefano Brivio <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
Diffstat (limited to 'net/tipc/socket.c')
0 files changed, 0 insertions, 0 deletions