From 304b44f0d5a4c2f91f82f7c31538d00485fb484c Mon Sep 17 00:00:00 2001 From: Antony Antony Date: Tue, 30 Apr 2024 09:09:29 +0200 Subject: [PATCH] xfrm: Add dir validation to "in" data path lookup Introduces validation for the x->dir attribute within the XFRM input data lookup path. If the configured direction does not match the expected direction, input, increment the XfrmInStateDirError counter and drop the packet to ensure data integrity and correct flow handling. grep -vw 0 /proc/net/xfrm_stat XfrmInStateDirError 1 Signed-off-by: Antony Antony Reviewed-by: Sabrina Dubroca Reviewed-by: Nicolas Dichtel Signed-off-by: Steffen Klassert --- Documentation/networking/xfrm_proc.rst | 3 +++ include/uapi/linux/snmp.h | 1 + net/ipv6/xfrm6_input.c | 7 +++++++ net/xfrm/xfrm_input.c | 11 +++++++++++ net/xfrm/xfrm_proc.c | 1 + 5 files changed, 23 insertions(+) diff --git a/Documentation/networking/xfrm_proc.rst b/Documentation/networking/xfrm_proc.rst index 5ac3acf4cf51..973d1571acac 100644 --- a/Documentation/networking/xfrm_proc.rst +++ b/Documentation/networking/xfrm_proc.rst @@ -73,6 +73,9 @@ XfrmAcquireError: XfrmFwdHdrError: Forward routing of a packet is not allowed +XfrmInStateDirError: + State direction mismatch (lookup found an output state on the input path, expected input or no direction) + Outbound errors ~~~~~~~~~~~~~~~ XfrmOutError: diff --git a/include/uapi/linux/snmp.h b/include/uapi/linux/snmp.h index 23792b8412bd..adf5fd78dd50 100644 --- a/include/uapi/linux/snmp.h +++ b/include/uapi/linux/snmp.h @@ -338,6 +338,7 @@ enum LINUX_MIB_XFRMOUTSTATEINVALID, /* XfrmOutStateInvalid */ LINUX_MIB_XFRMACQUIREERROR, /* XfrmAcquireError */ LINUX_MIB_XFRMOUTSTATEDIRERROR, /* XfrmOutStateDirError */ + LINUX_MIB_XFRMINSTATEDIRERROR, /* XfrmInStateDirError */ __LINUX_MIB_XFRMMAX }; diff --git a/net/ipv6/xfrm6_input.c b/net/ipv6/xfrm6_input.c index 2c6aeb090b7a..d5bac0d76b6e 100644 --- a/net/ipv6/xfrm6_input.c +++ b/net/ipv6/xfrm6_input.c @@ -266,6 +266,13 @@ int xfrm6_input_addr(struct sk_buff *skb, xfrm_address_t *daddr, if (!x) continue; + if (unlikely(x->dir && x->dir != XFRM_SA_DIR_IN)) { + XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEDIRERROR); + xfrm_state_put(x); + x = NULL; + continue; + } + spin_lock(&x->lock); if ((!i || (x->props.flags & XFRM_STATE_WILDRECV)) && diff --git a/net/xfrm/xfrm_input.c b/net/xfrm/xfrm_input.c index 161f535c8b94..71b42de6e3c9 100644 --- a/net/xfrm/xfrm_input.c +++ b/net/xfrm/xfrm_input.c @@ -466,6 +466,11 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type) if (encap_type < 0 || (xo && xo->flags & XFRM_GRO)) { x = xfrm_input_state(skb); + if (unlikely(x->dir && x->dir != XFRM_SA_DIR_IN)) { + XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEDIRERROR); + goto drop; + } + if (unlikely(x->km.state != XFRM_STATE_VALID)) { if (x->km.state == XFRM_STATE_ACQ) XFRM_INC_STATS(net, LINUX_MIB_XFRMACQUIREERROR); @@ -571,6 +576,12 @@ int xfrm_input(struct sk_buff *skb, int nexthdr, __be32 spi, int encap_type) goto drop; } + if (unlikely(x->dir && x->dir != XFRM_SA_DIR_IN)) { + XFRM_INC_STATS(net, LINUX_MIB_XFRMINSTATEDIRERROR); + xfrm_state_put(x); + goto drop; + } + skb->mark = xfrm_smark_get(skb->mark, x); sp->xvec[sp->len++] = x; diff --git a/net/xfrm/xfrm_proc.c b/net/xfrm/xfrm_proc.c index 98606f1078f7..eeb984be03a7 100644 --- a/net/xfrm/xfrm_proc.c +++ b/net/xfrm/xfrm_proc.c @@ -42,6 +42,7 @@ static const struct snmp_mib xfrm_mib_list[] = { SNMP_MIB_ITEM("XfrmOutStateInvalid", LINUX_MIB_XFRMOUTSTATEINVALID), SNMP_MIB_ITEM("XfrmAcquireError", LINUX_MIB_XFRMACQUIREERROR), SNMP_MIB_ITEM("XfrmOutStateDirError", LINUX_MIB_XFRMOUTSTATEDIRERROR), + SNMP_MIB_ITEM("XfrmInStateDirError", LINUX_MIB_XFRMINSTATEDIRERROR), SNMP_MIB_SENTINEL };