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| author | Daniel Borkmann <dborkman@redhat.com> | 2013-08-05 14:49:35 +0400 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2013-08-05 23:26:50 +0400 |
| commit | 7921895a5e852fc99de347bc0600659997de9298 (patch) | |
| tree | 0806f91433c6a67fa20a679d9c5db4809cf981d9 /net/ipv4/esp4.c | |
| parent | 07ce76aa9bcf8bc106a53c67548c5602f1598595 (diff) | |
| download | linux-7921895a5e852fc99de347bc0600659997de9298.tar.xz | |
net: esp{4,6}: fix potential MTU calculation overflows
Commit 91657eafb ("xfrm: take net hdr len into account for esp payload
size calculation") introduced a possible interger overflow in
esp{4,6}_get_mtu() handlers in case of x->props.mode equals
XFRM_MODE_TUNNEL. Thus, the following expression will overflow
unsigned int net_adj;
...
<case ipv{4,6} XFRM_MODE_TUNNEL>
net_adj = 0;
...
return ((mtu - x->props.header_len - crypto_aead_authsize(esp->aead) -
net_adj) & ~(align - 1)) + (net_adj - 2);
where (net_adj - 2) would be evaluated as <foo> + (0 - 2) in an unsigned
context. Fix it by simply removing brackets as those operations here
do not need to have special precedence.
Signed-off-by: Daniel Borkmann <dborkman@redhat.com>
Cc: Benjamin Poirier <bpoirier@suse.de>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Benjamin Poirier <bpoirier@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/ipv4/esp4.c')
| -rw-r--r-- | net/ipv4/esp4.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c index ab3d814bc80a..109ee89f123e 100644 --- a/net/ipv4/esp4.c +++ b/net/ipv4/esp4.c @@ -477,7 +477,7 @@ static u32 esp4_get_mtu(struct xfrm_state *x, int mtu) } return ((mtu - x->props.header_len - crypto_aead_authsize(esp->aead) - - net_adj) & ~(align - 1)) + (net_adj - 2); + net_adj) & ~(align - 1)) + net_adj - 2; } static void esp4_err(struct sk_buff *skb, u32 info) |