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>

1 files changed, 21 insertions, 4 deletions

diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c
index d88e96d4e12c..56ba0f2a01db 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;
 }