1

xfrm: Add dir validation to "out" data path lookup

Introduces validation for the x->dir attribute within the XFRM output
data lookup path. If the configured direction does not match the expected
direction, output, increment the XfrmOutStateDirError counter and drop
the packet to ensure data integrity and correct flow handling.

grep -vw 0 /proc/net/xfrm_stat
XfrmOutPolError         	1
XfrmOutStateDirError    	1

Signed-off-by: Antony Antony <antony.antony@secunet.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
This commit is contained in:
Antony Antony 2024-04-30 09:09:09 +02:00 committed by Steffen Klassert
parent a4a87fa4e9
commit 601a0867f8
4 changed files with 11 additions and 0 deletions

View File

@ -111,3 +111,6 @@ XfrmOutPolError:
XfrmOutStateInvalid:
State is invalid, perhaps expired
XfrmOutStateDirError:
State direction mismatch (lookup found an input state on the output path, expected output or no direction)

View File

@ -337,6 +337,7 @@ enum
LINUX_MIB_XFRMFWDHDRERROR, /* XfrmFwdHdrError*/
LINUX_MIB_XFRMOUTSTATEINVALID, /* XfrmOutStateInvalid */
LINUX_MIB_XFRMACQUIREERROR, /* XfrmAcquireError */
LINUX_MIB_XFRMOUTSTATEDIRERROR, /* XfrmOutStateDirError */
__LINUX_MIB_XFRMMAX
};

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@ -2489,6 +2489,12 @@ xfrm_tmpl_resolve_one(struct xfrm_policy *policy, const struct flowi *fl,
x = xfrm_state_find(remote, local, fl, tmpl, policy, &error,
family, policy->if_id);
if (x && x->dir && x->dir != XFRM_SA_DIR_OUT) {
XFRM_INC_STATS(net, LINUX_MIB_XFRMOUTSTATEDIRERROR);
xfrm_state_put(x);
error = -EINVAL;
goto fail;
}
if (x && x->km.state == XFRM_STATE_VALID) {
xfrm[nx++] = x;

View File

@ -41,6 +41,7 @@ static const struct snmp_mib xfrm_mib_list[] = {
SNMP_MIB_ITEM("XfrmFwdHdrError", LINUX_MIB_XFRMFWDHDRERROR),
SNMP_MIB_ITEM("XfrmOutStateInvalid", LINUX_MIB_XFRMOUTSTATEINVALID),
SNMP_MIB_ITEM("XfrmAcquireError", LINUX_MIB_XFRMACQUIREERROR),
SNMP_MIB_ITEM("XfrmOutStateDirError", LINUX_MIB_XFRMOUTSTATEDIRERROR),
SNMP_MIB_SENTINEL
};