Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2018-04-21

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) Fix a deadlock between mm->mmap_sem and bpf_event_mutex when
   one task is detaching a BPF prog via perf_event_detach_bpf_prog()
   and another one dumping through bpf_prog_array_copy_info(). For
   the latter we move the copy_to_user() out of the bpf_event_mutex
   lock to fix it, from Yonghong.

2) Fix test_sock and test_sock_addr.sh failures. The former was
   hitting rlimit issues and the latter required ping to specify
   the address family, from Yonghong.

3) Remove a dead check in sockmap's sock_map_alloc(), from Jann.

4) Add generated files to BPF kselftests gitignore that were previously
   missed, from Anders.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

3 files changed, 50 insertions, 23 deletions

diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index d315b39..ba03ec3 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -1572,13 +1572,32 @@ int bpf_prog_array_length(struct bpf_prog_array __rcu *progs)
 	return cnt;
 }
 
+static bool bpf_prog_array_copy_core(struct bpf_prog **prog,
+				     u32 *prog_ids,
+				     u32 request_cnt)
+{
+	int i = 0;
+
+	for (; *prog; prog++) {
+		if (*prog == &dummy_bpf_prog.prog)
+			continue;
+		prog_ids[i] = (*prog)->aux->id;
+		if (++i == request_cnt) {
+			prog++;
+			break;
+		}
+	}
+
+	return !!(*prog);
+}
+
 int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *progs,
 				__u32 __user *prog_ids, u32 cnt)
 {
 	struct bpf_prog **prog;
 	unsigned long err = 0;
-	u32 i = 0, *ids;
 	bool nospc;
+	u32 *ids;
 
 	/* users of this function are doing:
 	 * cnt = bpf_prog_array_length();
@@ -1595,16 +1614,7 @@ int bpf_prog_array_copy_to_user(struct bpf_prog_array __rcu *progs,
 		return -ENOMEM;
 	rcu_read_lock();
 	prog = rcu_dereference(progs)->progs;
-	for (; *prog; prog++) {
-		if (*prog == &dummy_bpf_prog.prog)
-			continue;
-		ids[i] = (*prog)->aux->id;
-		if (++i == cnt) {
-			prog++;
-			break;
-		}
-	}
-	nospc = !!(*prog);
+	nospc = bpf_prog_array_copy_core(prog, ids, cnt);
 	rcu_read_unlock();
 	err = copy_to_user(prog_ids, ids, cnt * sizeof(u32));
 	kfree(ids);
@@ -1683,22 +1693,25 @@ int bpf_prog_array_copy(struct bpf_prog_array __rcu *old_array,
 }
 
 int bpf_prog_array_copy_info(struct bpf_prog_array __rcu *array,
-			     __u32 __user *prog_ids, u32 request_cnt,
-			     __u32 __user *prog_cnt)
+			     u32 *prog_ids, u32 request_cnt,
+			     u32 *prog_cnt)
 {
+	struct bpf_prog **prog;
 	u32 cnt = 0;
 
 	if (array)
 		cnt = bpf_prog_array_length(array);
 
-	if (copy_to_user(prog_cnt, &cnt, sizeof(cnt)))
-		return -EFAULT;
+	*prog_cnt = cnt;
 
 	/* return early if user requested only program count or nothing to copy */
 	if (!request_cnt || !cnt)
 		return 0;
 
-	return bpf_prog_array_copy_to_user(array, prog_ids, request_cnt);
+	/* this function is called under trace/bpf_trace.c: bpf_event_mutex */
+	prog = rcu_dereference_check(array, 1)->progs;
+	return bpf_prog_array_copy_core(prog, prog_ids, request_cnt) ? -ENOSPC
+								     : 0;
 }
 
 static void bpf_prog_free_deferred(struct work_struct *work)
diff --git a/kernel/bpf/sockmap.c b/kernel/bpf/sockmap.c
index 8dd9210..a3b2138 100644
--- a/kernel/bpf/sockmap.c
+++ b/kernel/bpf/sockmap.c
@@ -1442,9 +1442,6 @@ static struct bpf_map *sock_map_alloc(union bpf_attr *attr)
 	    attr->value_size != 4 || attr->map_flags & ~SOCK_CREATE_FLAG_MASK)
 		return ERR_PTR(-EINVAL);
 
-	if (attr->value_size > KMALLOC_MAX_SIZE)
-		return ERR_PTR(-E2BIG);
-
 	err = bpf_tcp_ulp_register();
 	if (err && err != -EEXIST)
 		return ERR_PTR(err);
diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index d88e96d..56ba0f2 100644
--- a/kernel/trace/bpf_trace.c
+++ b/kernel/trace/bpf_trace.c
@@ -977,6 +977,7 @@ int perf_event_query_prog_array(struct perf_event *event, void __user *info)
 {
 	struct perf_event_query_bpf __user *uquery = info;
 	struct perf_event_query_bpf query = {};
+	u32 *ids, prog_cnt, ids_len;
 	int ret;
 
 	if (!capable(CAP_SYS_ADMIN))
@@ -985,16 +986,32 @@ int perf_event_query_prog_array(struct perf_event *event, void __user *info)
 		return -EINVAL;
 	if (copy_from_user(&query, uquery, sizeof(query)))
 		return -EFAULT;
-	if (query.ids_len > BPF_TRACE_MAX_PROGS)
+
+	ids_len = query.ids_len;
+	if (ids_len > BPF_TRACE_MAX_PROGS)
 		return -E2BIG;
+	ids = kcalloc(ids_len, sizeof(u32), GFP_USER | __GFP_NOWARN);
+	if (!ids)
+		return -ENOMEM;
+	/*
+	 * The above kcalloc returns ZERO_SIZE_PTR when ids_len = 0, which
+	 * is required when user only wants to check for uquery->prog_cnt.
+	 * There is no need to check for it since the case is handled
+	 * gracefully in bpf_prog_array_copy_info.
+	 */
 
 	mutex_lock(&bpf_event_mutex);
 	ret = bpf_prog_array_copy_info(event->tp_event->prog_array,
-				       uquery->ids,
-				       query.ids_len,
-				       &uquery->prog_cnt);
+				       ids,
+				       ids_len,
+				       &prog_cnt);
 	mutex_unlock(&bpf_event_mutex);
 
+	if (copy_to_user(&uquery->prog_cnt, &prog_cnt, sizeof(prog_cnt)) ||
+	    copy_to_user(uquery->ids, ids, ids_len * sizeof(u32)))
+		ret = -EFAULT;
+
+	kfree(ids);
 	return ret;
 }