Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 321 insertions, 0 deletions

diff --git a/net/ipv6/seg6_hmac.c b/net/ipv6/seg6_hmac.c
new file mode 100644
index 000000000..e6964c6b0
--- /dev/null
+++ b/net/ipv6/seg6_hmac.c
@@ -0,0 +1,321 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  SR-IPv6 implementation -- HMAC functions
+ *
+ *  Author:
+ *  David Lebrun <david.lebrun@uclouvain.be>
+ */
+
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/socket.h>
+#include <linux/sockios.h>
+#include <linux/net.h>
+#include <linux/netdevice.h>
+#include <linux/in6.h>
+#include <linux/icmpv6.h>
+#include <linux/mroute6.h>
+#include <linux/rhashtable.h>
+
+#include <linux/netfilter.h>
+#include <linux/netfilter_ipv6.h>
+
+#include <net/sock.h>
+#include <net/snmp.h>
+
+#include <net/ipv6.h>
+#include <net/protocol.h>
+#include <net/transp_v6.h>
+#include <net/rawv6.h>
+#include <net/ndisc.h>
+#include <net/ip6_route.h>
+#include <net/addrconf.h>
+#include <net/xfrm.h>
+
+#include <crypto/sha1.h>
+#include <crypto/sha2.h>
+#include <crypto/utils.h>
+#include <net/seg6.h>
+#include <net/genetlink.h>
+#include <net/seg6_hmac.h>
+#include <linux/random.h>
+
+struct hmac_storage {
+	local_lock_t bh_lock;
+	char hmac_ring[SEG6_HMAC_RING_SIZE];
+};
+
+static DEFINE_PER_CPU(struct hmac_storage, hmac_storage) = {
+	.bh_lock = INIT_LOCAL_LOCK(bh_lock),
+};
+
+static int seg6_hmac_cmpfn(struct rhashtable_compare_arg *arg, const void *obj)
+{
+	const struct seg6_hmac_info *hinfo = obj;
+
+	return (hinfo->hmackeyid != *(__u32 *)arg->key);
+}
+
+static inline void seg6_hinfo_release(struct seg6_hmac_info *hinfo)
+{
+	kfree_rcu(hinfo, rcu);
+}
+
+static void seg6_free_hi(void *ptr, void *arg)
+{
+	struct seg6_hmac_info *hinfo = (struct seg6_hmac_info *)ptr;
+
+	if (hinfo)
+		seg6_hinfo_release(hinfo);
+}
+
+static const struct rhashtable_params rht_params = {
+	.head_offset		= offsetof(struct seg6_hmac_info, node),
+	.key_offset		= offsetof(struct seg6_hmac_info, hmackeyid),
+	.key_len		= sizeof(u32),
+	.automatic_shrinking	= true,
+	.obj_cmpfn		= seg6_hmac_cmpfn,
+};
+
+static struct sr6_tlv_hmac *seg6_get_tlv_hmac(struct ipv6_sr_hdr *srh)
+{
+	struct sr6_tlv_hmac *tlv;
+
+	if (srh->hdrlen < (srh->first_segment + 1) * 2 + 5)
+		return NULL;
+
+	if (!sr_has_hmac(srh))
+		return NULL;
+
+	tlv = (struct sr6_tlv_hmac *)
+	      ((char *)srh + ((srh->hdrlen + 1) << 3) - 40);
+
+	if (tlv->tlvhdr.type != SR6_TLV_HMAC || tlv->tlvhdr.len != 38)
+		return NULL;
+
+	return tlv;
+}
+
+int seg6_hmac_compute(struct seg6_hmac_info *hinfo, struct ipv6_sr_hdr *hdr,
+		      struct in6_addr *saddr, u8 *output)
+{
+	__be32 hmackeyid = cpu_to_be32(hinfo->hmackeyid);
+	int plen, i, ret = 0;
+	char *ring, *off;
+
+	/* saddr(16) + first_seg(1) + flags(1) + keyid(4) + seglist(16n) */
+	plen = 16 + 1 + 1 + 4 + (hdr->first_segment + 1) * 16;
+
+	/* this limit allows for 14 segments */
+	if (plen >= SEG6_HMAC_RING_SIZE)
+		return -EMSGSIZE;
+
+	/* Let's build the HMAC text on the ring buffer. The text is composed
+	 * as follows, in order:
+	 *
+	 * 1. Source IPv6 address (128 bits)
+	 * 2. first_segment value (8 bits)
+	 * 3. Flags (8 bits)
+	 * 4. HMAC Key ID (32 bits)
+	 * 5. All segments in the segments list (n * 128 bits)
+	 */
+
+	local_bh_disable();
+	local_lock_nested_bh(&hmac_storage.bh_lock);
+	ring = this_cpu_ptr(hmac_storage.hmac_ring);
+	off = ring;
+
+	/* source address */
+	memcpy(off, saddr, 16);
+	off += 16;
+
+	/* first_segment value */
+	*off++ = hdr->first_segment;
+
+	/* flags */
+	*off++ = hdr->flags;
+
+	/* HMAC Key ID */
+	memcpy(off, &hmackeyid, 4);
+	off += 4;
+
+	/* all segments in the list */
+	for (i = 0; i < hdr->first_segment + 1; i++) {
+		memcpy(off, hdr->segments + i, 16);
+		off += 16;
+	}
+
+	switch (hinfo->alg_id) {
+	case SEG6_HMAC_ALGO_SHA1:
+		hmac_sha1(&hinfo->key.sha1, ring, plen, output);
+		static_assert(SEG6_HMAC_FIELD_LEN > SHA1_DIGEST_SIZE);
+		memset(&output[SHA1_DIGEST_SIZE], 0,
+		       SEG6_HMAC_FIELD_LEN - SHA1_DIGEST_SIZE);
+		break;
+	case SEG6_HMAC_ALGO_SHA256:
+		hmac_sha256(&hinfo->key.sha256, ring, plen, output);
+		static_assert(SEG6_HMAC_FIELD_LEN == SHA256_DIGEST_SIZE);
+		break;
+	default:
+		WARN_ON_ONCE(1);
+		ret = -EINVAL;
+		break;
+	}
+	local_unlock_nested_bh(&hmac_storage.bh_lock);
+	local_bh_enable();
+	return ret;
+}
+EXPORT_SYMBOL(seg6_hmac_compute);
+
+/* checks if an incoming SR-enabled packet's HMAC status matches
+ * the incoming policy.
+ *
+ * called with rcu_read_lock()
+ */
+bool seg6_hmac_validate_skb(struct sk_buff *skb)
+{
+	u8 hmac_output[SEG6_HMAC_FIELD_LEN];
+	struct net *net = dev_net(skb->dev);
+	struct seg6_hmac_info *hinfo;
+	struct sr6_tlv_hmac *tlv;
+	struct ipv6_sr_hdr *srh;
+	struct inet6_dev *idev;
+	int require_hmac;
+
+	idev = __in6_dev_get(skb->dev);
+	if (!idev)
+		return false;
+
+	srh = (struct ipv6_sr_hdr *)skb_transport_header(skb);
+
+	tlv = seg6_get_tlv_hmac(srh);
+
+	require_hmac = READ_ONCE(idev->cnf.seg6_require_hmac);
+	/* mandatory check but no tlv */
+	if (require_hmac > 0 && !tlv)
+		return false;
+
+	/* no check */
+	if (require_hmac < 0)
+		return true;
+
+	/* check only if present */
+	if (require_hmac == 0 && !tlv)
+		return true;
+
+	/* now, seg6_require_hmac >= 0 && tlv */
+
+	hinfo = seg6_hmac_info_lookup(net, be32_to_cpu(tlv->hmackeyid));
+	if (!hinfo)
+		return false;
+
+	if (seg6_hmac_compute(hinfo, srh, &ipv6_hdr(skb)->saddr, hmac_output))
+		return false;
+
+	if (crypto_memneq(hmac_output, tlv->hmac, SEG6_HMAC_FIELD_LEN))
+		return false;
+
+	return true;
+}
+EXPORT_SYMBOL(seg6_hmac_validate_skb);
+
+/* called with rcu_read_lock() */
+struct seg6_hmac_info *seg6_hmac_info_lookup(struct net *net, u32 key)
+{
+	struct seg6_pernet_data *sdata = seg6_pernet(net);
+	struct seg6_hmac_info *hinfo;
+
+	hinfo = rhashtable_lookup_fast(&sdata->hmac_infos, &key, rht_params);
+
+	return hinfo;
+}
+EXPORT_SYMBOL(seg6_hmac_info_lookup);
+
+int seg6_hmac_info_add(struct net *net, u32 key, struct seg6_hmac_info *hinfo)
+{
+	struct seg6_pernet_data *sdata = seg6_pernet(net);
+	int err;
+
+	switch (hinfo->alg_id) {
+	case SEG6_HMAC_ALGO_SHA1:
+		hmac_sha1_preparekey(&hinfo->key.sha1,
+				     hinfo->secret, hinfo->slen);
+		break;
+	case SEG6_HMAC_ALGO_SHA256:
+		hmac_sha256_preparekey(&hinfo->key.sha256,
+				       hinfo->secret, hinfo->slen);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	err = rhashtable_lookup_insert_fast(&sdata->hmac_infos, &hinfo->node,
+					    rht_params);
+
+	return err;
+}
+EXPORT_SYMBOL(seg6_hmac_info_add);
+
+int seg6_hmac_info_del(struct net *net, u32 key)
+{
+	struct seg6_pernet_data *sdata = seg6_pernet(net);
+	struct seg6_hmac_info *hinfo;
+	int err = -ENOENT;
+
+	hinfo = rhashtable_lookup_fast(&sdata->hmac_infos, &key, rht_params);
+	if (!hinfo)
+		goto out;
+
+	err = rhashtable_remove_fast(&sdata->hmac_infos, &hinfo->node,
+				     rht_params);
+	if (err)
+		goto out;
+
+	seg6_hinfo_release(hinfo);
+
+out:
+	return err;
+}
+EXPORT_SYMBOL(seg6_hmac_info_del);
+
+int seg6_push_hmac(struct net *net, struct in6_addr *saddr,
+		   struct ipv6_sr_hdr *srh)
+{
+	struct seg6_hmac_info *hinfo;
+	struct sr6_tlv_hmac *tlv;
+	int err = -ENOENT;
+
+	tlv = seg6_get_tlv_hmac(srh);
+	if (!tlv)
+		return -EINVAL;
+
+	rcu_read_lock();
+
+	hinfo = seg6_hmac_info_lookup(net, be32_to_cpu(tlv->hmackeyid));
+	if (!hinfo)
+		goto out;
+
+	memset(tlv->hmac, 0, SEG6_HMAC_FIELD_LEN);
+	err = seg6_hmac_compute(hinfo, srh, saddr, tlv->hmac);
+
+out:
+	rcu_read_unlock();
+	return err;
+}
+EXPORT_SYMBOL(seg6_push_hmac);
+
+int __net_init seg6_hmac_net_init(struct net *net)
+{
+	struct seg6_pernet_data *sdata = seg6_pernet(net);
+
+	return rhashtable_init(&sdata->hmac_infos, &rht_params);
+}
+
+void __net_exit seg6_hmac_net_exit(struct net *net)
+{
+	struct seg6_pernet_data *sdata = seg6_pernet(net);
+
+	rhashtable_free_and_destroy(&sdata->hmac_infos, seg6_free_hi, NULL);
+}
+EXPORT_SYMBOL(seg6_hmac_net_exit);