From: Xin Long lucien.xin@gmail.com

commit 4f47e8ab6ab796b5380f74866fa5287aca4dcc58 upstream.

In commit ed17b8d377ea ("xfrm: fix a warning in xfrm_policy_insert_list"), it would take 'priority' to make a policy unique, and allow duplicated policies with different 'priority' to be added, which is not expected by userland, as Tobias reported in strongswan.

To fix this duplicated policies issue, and also fix the issue in commit ed17b8d377ea ("xfrm: fix a warning in xfrm_policy_insert_list"), when doing add/del/get/update on user interfaces, this patch is to change to look up a policy with both mark and mask by doing:

mark.v == pol->mark.v && mark.m == pol->mark.m

and leave the check:

(mark & pol->mark.m) == pol->mark.v

for tx/rx path only.

As the userland expects an exact mark and mask match to manage policies.

v1->v2: - make xfrm_policy_mark_match inline and fix the changelog as Tobias suggested.

Cc: stable@vger.kernel.org # 4.19.x Fixes: 295fae568885 ("xfrm: Allow user space manipulation of SPD mark") Fixes: ed17b8d377ea ("xfrm: fix a warning in xfrm_policy_insert_list") Reported-by: Tobias Brunner tobias@strongswan.org Tested-by: Tobias Brunner tobias@strongswan.org Signed-off-by: Xin Long lucien.xin@gmail.com Signed-off-by: Steffen Klassert steffen.klassert@secunet.com --- This is a backport to 4.19.x of a fix that has already been applied to newer stable kernels. However, due to conflicts it was never included in the 4.x trees, which all contain backports of the problematic commit referenced above (ed17b8d377ea). So they all are prone to creating duplicate IPsec policies with priority updates.

include/net/xfrm.h | 11 +++++++---- net/key/af_key.c | 4 ++-- net/xfrm/xfrm_policy.c | 32 +++++++++++++------------------- net/xfrm/xfrm_user.c | 18 +++++++++++------- 4 files changed, 33 insertions(+), 32 deletions(-)

diff --git a/include/net/xfrm.h b/include/net/xfrm.h index a8aa2bb74ad6..6b18cd0e511a 100644 --- a/include/net/xfrm.h +++ b/include/net/xfrm.h @@ -1739,13 +1739,16 @@ int xfrm_policy_walk(struct net *net, struct xfrm_policy_walk *walk, void *); void xfrm_policy_walk_done(struct xfrm_policy_walk *walk, struct net *net); int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl); -struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark, u32 if_id, - u8 type, int dir, +struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, + const struct xfrm_mark *mark, + u32 if_id, u8 type, int dir, struct xfrm_selector *sel, struct xfrm_sec_ctx *ctx, int delete, int *err); -struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u32 if_id, u8, - int dir, u32 id, int delete, int *err); +struct xfrm_policy *xfrm_policy_byid(struct net *net, + const struct xfrm_mark *mark, u32 if_id, + u8 type, int dir, u32 id, int delete, + int *err); int xfrm_policy_flush(struct net *net, u8 type, bool task_valid); void xfrm_policy_hash_rebuild(struct net *net); u32 xfrm_get_acqseq(void); diff --git a/net/key/af_key.c b/net/key/af_key.c index 388910cf0978..e252f7cf30ad 100644 --- a/net/key/af_key.c +++ b/net/key/af_key.c @@ -2413,7 +2413,7 @@ static int pfkey_spddelete(struct sock *sk, struct sk_buff *skb, const struct sa return err; }

- xp = xfrm_policy_bysel_ctx(net, DUMMY_MARK, 0, XFRM_POLICY_TYPE_MAIN, + xp = xfrm_policy_bysel_ctx(net, &dummy_mark, 0, XFRM_POLICY_TYPE_MAIN, pol->sadb_x_policy_dir - 1, &sel, pol_ctx, 1, &err); security_xfrm_policy_free(pol_ctx); @@ -2664,7 +2664,7 @@ static int pfkey_spdget(struct sock *sk, struct sk_buff *skb, const struct sadb_ return -EINVAL;

delete = (hdr->sadb_msg_type == SADB_X_SPDDELETE2); - xp = xfrm_policy_byid(net, DUMMY_MARK, 0, XFRM_POLICY_TYPE_MAIN, + xp = xfrm_policy_byid(net, &dummy_mark, 0, XFRM_POLICY_TYPE_MAIN, dir, pol->sadb_x_policy_id, delete, &err); if (xp == NULL) return -ENOENT; diff --git a/net/xfrm/xfrm_policy.c b/net/xfrm/xfrm_policy.c index ab6d0c6576a6..bb1c94e20e82 100644 --- a/net/xfrm/xfrm_policy.c +++ b/net/xfrm/xfrm_policy.c @@ -727,14 +727,10 @@ static void xfrm_policy_requeue(struct xfrm_policy *old, spin_unlock_bh(&pq->hold_queue.lock); }

-static bool xfrm_policy_mark_match(struct xfrm_policy *policy, - struct xfrm_policy *pol) +static inline bool xfrm_policy_mark_match(const struct xfrm_mark *mark, + struct xfrm_policy *pol) { - if (policy->mark.v == pol->mark.v && - policy->priority == pol->priority) - return true; - - return false; + return mark->v == pol->mark.v && mark->m == pol->mark.m; }

int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl) @@ -753,7 +749,7 @@ int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl) if (pol->type == policy->type && pol->if_id == policy->if_id && !selector_cmp(&pol->selector, &policy->selector) && - xfrm_policy_mark_match(policy, pol) && + xfrm_policy_mark_match(&policy->mark, pol) && xfrm_sec_ctx_match(pol->security, policy->security) && !WARN_ON(delpol)) { if (excl) { @@ -803,11 +799,10 @@ int xfrm_policy_insert(int dir, struct xfrm_policy *policy, int excl) } EXPORT_SYMBOL(xfrm_policy_insert);

-struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark, u32 if_id, - u8 type, int dir, - struct xfrm_selector *sel, - struct xfrm_sec_ctx *ctx, int delete, - int *err) +struct xfrm_policy * +xfrm_policy_bysel_ctx(struct net *net, const struct xfrm_mark *mark, u32 if_id, + u8 type, int dir, struct xfrm_selector *sel, + struct xfrm_sec_ctx *ctx, int delete, int *err) { struct xfrm_policy *pol, *ret; struct hlist_head *chain; @@ -819,7 +814,7 @@ struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark, u32 if_id, hlist_for_each_entry(pol, chain, bydst) { if (pol->type == type && pol->if_id == if_id && - (mark & pol->mark.m) == pol->mark.v && + xfrm_policy_mark_match(mark, pol) && !selector_cmp(sel, &pol->selector) && xfrm_sec_ctx_match(ctx, pol->security)) { xfrm_pol_hold(pol); @@ -844,9 +839,9 @@ struct xfrm_policy *xfrm_policy_bysel_ctx(struct net *net, u32 mark, u32 if_id, } EXPORT_SYMBOL(xfrm_policy_bysel_ctx);

-struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u32 if_id, - u8 type, int dir, u32 id, int delete, - int *err) +struct xfrm_policy * +xfrm_policy_byid(struct net *net, const struct xfrm_mark *mark, u32 if_id, + u8 type, int dir, u32 id, int delete, int *err) { struct xfrm_policy *pol, *ret; struct hlist_head *chain; @@ -861,8 +856,7 @@ struct xfrm_policy *xfrm_policy_byid(struct net *net, u32 mark, u32 if_id, ret = NULL; hlist_for_each_entry(pol, chain, byidx) { if (pol->type == type && pol->index == id && - pol->if_id == if_id && - (mark & pol->mark.m) == pol->mark.v) { + pol->if_id == if_id && xfrm_policy_mark_match(mark, pol)) { xfrm_pol_hold(pol); if (delete) { *err = security_xfrm_policy_delete( diff --git a/net/xfrm/xfrm_user.c b/net/xfrm/xfrm_user.c index 3db5cd70b16a..94c7ebc26c48 100644 --- a/net/xfrm/xfrm_user.c +++ b/net/xfrm/xfrm_user.c @@ -1862,7 +1862,6 @@ static int xfrm_get_policy(struct sk_buff *skb, struct nlmsghdr *nlh, struct km_event c; int delete; struct xfrm_mark m; - u32 mark = xfrm_mark_get(attrs, &m); u32 if_id = 0;

p = nlmsg_data(nlh); @@ -1879,8 +1878,11 @@ static int xfrm_get_policy(struct sk_buff *skb, struct nlmsghdr *nlh, if (attrs[XFRMA_IF_ID]) if_id = nla_get_u32(attrs[XFRMA_IF_ID]);

+ xfrm_mark_get(attrs, &m); + if (p->index) - xp = xfrm_policy_byid(net, mark, if_id, type, p->dir, p->index, delete, &err); + xp = xfrm_policy_byid(net, &m, if_id, type, p->dir, + p->index, delete, &err); else { struct nlattr *rt = attrs[XFRMA_SEC_CTX]; struct xfrm_sec_ctx *ctx; @@ -1897,8 +1899,8 @@ static int xfrm_get_policy(struct sk_buff *skb, struct nlmsghdr *nlh, if (err) return err; } - xp = xfrm_policy_bysel_ctx(net, mark, if_id, type, p->dir, &p->sel, - ctx, delete, &err); + xp = xfrm_policy_bysel_ctx(net, &m, if_id, type, p->dir, + &p->sel, ctx, delete, &err); security_xfrm_policy_free(ctx); } if (xp == NULL) @@ -2165,7 +2167,6 @@ static int xfrm_add_pol_expire(struct sk_buff *skb, struct nlmsghdr *nlh, u8 type = XFRM_POLICY_TYPE_MAIN; int err = -ENOENT; struct xfrm_mark m; - u32 mark = xfrm_mark_get(attrs, &m); u32 if_id = 0;

err = copy_from_user_policy_type(&type, attrs); @@ -2179,8 +2180,11 @@ static int xfrm_add_pol_expire(struct sk_buff *skb, struct nlmsghdr *nlh, if (attrs[XFRMA_IF_ID]) if_id = nla_get_u32(attrs[XFRMA_IF_ID]);

+ xfrm_mark_get(attrs, &m); + if (p->index) - xp = xfrm_policy_byid(net, mark, if_id, type, p->dir, p->index, 0, &err); + xp = xfrm_policy_byid(net, &m, if_id, type, p->dir, p->index, + 0, &err); else { struct nlattr *rt = attrs[XFRMA_SEC_CTX]; struct xfrm_sec_ctx *ctx; @@ -2197,7 +2201,7 @@ static int xfrm_add_pol_expire(struct sk_buff *skb, struct nlmsghdr *nlh, if (err) return err; } - xp = xfrm_policy_bysel_ctx(net, mark, if_id, type, p->dir, + xp = xfrm_policy_bysel_ctx(net, &m, if_id, type, p->dir, &p->sel, ctx, 0, &err); security_xfrm_policy_free(ctx); }