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

Daniel Borkmann says:

====================
pull-request: bpf 2021-01-16

1) Fix a double bpf_prog_put() for BPF_PROG_{TYPE_EXT,TYPE_TRACING} types in
   link creation's error path causing a refcount underflow, from Jiri Olsa.

2) Fix BTF validation errors for the case where kernel modules don't declare
   any new types and end up with an empty BTF, from Andrii Nakryiko.

3) Fix BPF local storage helpers to first check their {task,inode} owners for
   being NULL before access, from KP Singh.

4) Fix a memory leak in BPF setsockopt handling for the case where optlen is
   zero and thus temporary optval buffer should be freed, from Stanislav Fomichev.

5) Fix a syzbot memory allocation splat in BPF_PROG_TEST_RUN infra for
   raw_tracepoint caused by too big ctx_size_in, from Song Liu.

6) Fix LLVM code generation issues with verifier where PTR_TO_MEM{,_OR_NULL}
   registers were spilled to stack but not recognized, from Gilad Reti.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  MAINTAINERS: Update my email address
  selftests/bpf: Add verifier test for PTR_TO_MEM spill
  bpf: Support PTR_TO_MEM{,_OR_NULL} register spilling
  bpf: Reject too big ctx_size_in for raw_tp test run
  libbpf: Allow loading empty BTFs
  bpf: Allow empty module BTFs
  bpf: Don't leak memory in bpf getsockopt when optlen == 0
  bpf: Update local storage test to check handling of null ptrs
  bpf: Fix typo in bpf_inode_storage.c
  bpf: Local storage helpers should check nullness of owner ptr passed
  bpf: Prevent double bpf_prog_put call from bpf_tracing_prog_attach
====================

Link: https://lore.kernel.org/r/20210116002025.15706-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

6 files changed, 20 insertions, 9 deletions

diff --git a/kernel/bpf/bpf_inode_storage.c b/kernel/bpf/bpf_inode_storage.c
index 6edff97ad594..2f0597320b6d 100644
--- a/kernel/bpf/bpf_inode_storage.c
+++ b/kernel/bpf/bpf_inode_storage.c
@@ -176,14 +176,14 @@ BPF_CALL_4(bpf_inode_storage_get, struct bpf_map *, map, struct inode *, inode,
 	 * bpf_local_storage_update expects the owner to have a
 	 * valid storage pointer.
 	 */
-	if (!inode_storage_ptr(inode))
+	if (!inode || !inode_storage_ptr(inode))
 		return (unsigned long)NULL;
 
 	sdata = inode_storage_lookup(inode, map, true);
 	if (sdata)
 		return (unsigned long)sdata->data;
 
-	/* This helper must only called from where the inode is gurranteed
+	/* This helper must only called from where the inode is guaranteed
 	 * to have a refcount and cannot be freed.
 	 */
 	if (flags & BPF_LOCAL_STORAGE_GET_F_CREATE) {
@@ -200,7 +200,10 @@ BPF_CALL_4(bpf_inode_storage_get, struct bpf_map *, map, struct inode *, inode,
 BPF_CALL_2(bpf_inode_storage_delete,
 	   struct bpf_map *, map, struct inode *, inode)
 {
-	/* This helper must only called from where the inode is gurranteed
+	if (!inode)
+		return -EINVAL;
+
+	/* This helper must only called from where the inode is guaranteed
 	 * to have a refcount and cannot be freed.
 	 */
 	return inode_storage_delete(inode, map);
diff --git a/kernel/bpf/bpf_task_storage.c b/kernel/bpf/bpf_task_storage.c
index 4ef1959a78f2..e0da0258b732 100644
--- a/kernel/bpf/bpf_task_storage.c
+++ b/kernel/bpf/bpf_task_storage.c
@@ -218,7 +218,7 @@ BPF_CALL_4(bpf_task_storage_get, struct bpf_map *, map, struct task_struct *,
 	 * bpf_local_storage_update expects the owner to have a
 	 * valid storage pointer.
 	 */
-	if (!task_storage_ptr(task))
+	if (!task || !task_storage_ptr(task))
 		return (unsigned long)NULL;
 
 	sdata = task_storage_lookup(task, map, true);
@@ -243,6 +243,9 @@ BPF_CALL_4(bpf_task_storage_get, struct bpf_map *, map, struct task_struct *,
 BPF_CALL_2(bpf_task_storage_delete, struct bpf_map *, map, struct task_struct *,
 	   task)
 {
+	if (!task)
+		return -EINVAL;
+
 	/* This helper must only be called from places where the lifetime of the task
 	 * is guaranteed. Either by being refcounted or by being protected
 	 * by an RCU read-side critical section.
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 8d6bdb4f4d61..84a36ee4a4c2 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -4172,7 +4172,7 @@ static int btf_parse_hdr(struct btf_verifier_env *env)
 		return -ENOTSUPP;
 	}
 
-	if (btf_data_size == hdr->hdr_len) {
+	if (!btf->base_btf && btf_data_size == hdr->hdr_len) {
 		btf_verifier_log(env, "No data");
 		return -EINVAL;
 	}
diff --git a/kernel/bpf/cgroup.c b/kernel/bpf/cgroup.c
index 6ec088a96302..96555a8a2c54 100644
--- a/kernel/bpf/cgroup.c
+++ b/kernel/bpf/cgroup.c
@@ -1391,12 +1391,13 @@ int __cgroup_bpf_run_filter_setsockopt(struct sock *sk, int *level,
 		if (ctx.optlen != 0) {
 			*optlen = ctx.optlen;
 			*kernel_optval = ctx.optval;
+			/* export and don't free sockopt buf */
+			return 0;
 		}
 	}
 
 out:
-	if (ret)
-		sockopt_free_buf(&ctx);
+	sockopt_free_buf(&ctx);
 	return ret;
 }
 
diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c
index c3bb03c8371f..e5999d86c76e 100644
--- a/kernel/bpf/syscall.c
+++ b/kernel/bpf/syscall.c
@@ -2712,7 +2712,6 @@ out_unlock:
 out_put_prog:
 	if (tgt_prog_fd && tgt_prog)
 		bpf_prog_put(tgt_prog);
-	bpf_prog_put(prog);
 	return err;
 }
 
@@ -2825,7 +2824,10 @@ static int bpf_raw_tracepoint_open(const union bpf_attr *attr)
 			tp_name = prog->aux->attach_func_name;
 			break;
 		}
-		return bpf_tracing_prog_attach(prog, 0, 0);
+		err = bpf_tracing_prog_attach(prog, 0, 0);
+		if (err >= 0)
+			return err;
+		goto out_put_prog;
 	case BPF_PROG_TYPE_RAW_TRACEPOINT:
 	case BPF_PROG_TYPE_RAW_TRACEPOINT_WRITABLE:
 		if (strncpy_from_user(buf,
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 17270b8404f1..36af69fac591 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -2217,6 +2217,8 @@ static bool is_spillable_regtype(enum bpf_reg_type type)
 	case PTR_TO_RDWR_BUF:
 	case PTR_TO_RDWR_BUF_OR_NULL:
 	case PTR_TO_PERCPU_BTF_ID:
+	case PTR_TO_MEM:
+	case PTR_TO_MEM_OR_NULL:
 		return true;
 	default:
 		return false;