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

Daniel Borkmann says:

====================
pull-request: bpf 2021-01-29

1) Fix two copy_{from,to}_user() warn_on_once splats for BPF cgroup getsockopt
infra when user space is trying to race against optlen, from Loris Reiff.

2) Fix a missing fput() in BPF inode storage map update helper, from Pan Bian.

3) Fix a build error on unresolved symbols on disabled networking / keys LSM
hooks, from Mikko Ylinen.

4) Fix preload BPF prog build when the output directory from make points to a
relative path, from Quentin Monnet.

* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
bpf, preload: Fix build when $(O) points to a relative path
bpf: Drop disabled LSM hooks from the sleepable set
bpf, inode_storage: Put file handler if no storage was found
bpf, cgroup: Fix problematic bounds check
bpf, cgroup: Fix optlen WARN_ON_ONCE toctou
====================

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

kernel/bpf/bpf_inode_storage.c

···
 
 	fd = *(int *)key;
 	f = fget_raw(fd);
-	if (!f || !inode_storage_ptr(f->f_inode))
+	if (!f)
 		return -EBADF;
+	if (!inode_storage_ptr(f->f_inode)) {
+		fput(f);
+		return -EBADF;
+	}
 
 	sdata = bpf_local_storage_update(f->f_inode,
 					 (struct bpf_local_storage_map *)map,

kernel/bpf/bpf_lsm.c

···
 BTF_ID(func, bpf_lsm_file_lock)
 BTF_ID(func, bpf_lsm_file_open)
 BTF_ID(func, bpf_lsm_file_receive)
+
+#ifdef CONFIG_SECURITY_NETWORK
 BTF_ID(func, bpf_lsm_inet_conn_established)
+#endif /* CONFIG_SECURITY_NETWORK */
+
 BTF_ID(func, bpf_lsm_inode_create)
 BTF_ID(func, bpf_lsm_inode_free_security)
 BTF_ID(func, bpf_lsm_inode_getattr)
···
 BTF_ID(func, bpf_lsm_inode_unlink)
 BTF_ID(func, bpf_lsm_kernel_module_request)
 BTF_ID(func, bpf_lsm_kernfs_init_security)
+
+#ifdef CONFIG_KEYS
 BTF_ID(func, bpf_lsm_key_free)
+#endif /* CONFIG_KEYS */
+
 BTF_ID(func, bpf_lsm_mmap_file)
 BTF_ID(func, bpf_lsm_netlink_send)
 BTF_ID(func, bpf_lsm_path_notify)
···
 BTF_ID(func, bpf_lsm_sb_statfs)
 BTF_ID(func, bpf_lsm_sb_umount)
 BTF_ID(func, bpf_lsm_settime)
+
+#ifdef CONFIG_SECURITY_NETWORK
 BTF_ID(func, bpf_lsm_socket_accept)
 BTF_ID(func, bpf_lsm_socket_bind)
 BTF_ID(func, bpf_lsm_socket_connect)
···
 BTF_ID(func, bpf_lsm_socket_sendmsg)
 BTF_ID(func, bpf_lsm_socket_shutdown)
 BTF_ID(func, bpf_lsm_socket_socketpair)
+#endif /* CONFIG_SECURITY_NETWORK */
+
 BTF_ID(func, bpf_lsm_syslog)
 BTF_ID(func, bpf_lsm_task_alloc)
 BTF_ID(func, bpf_lsm_task_getsecid)

kernel/bpf/cgroup.c

···
 			goto out;
 		}
 
+		if (ctx.optlen < 0) {
+			ret = -EFAULT;
+			goto out;
+		}
+
 		if (copy_from_user(ctx.optval, optval,
 				   min(ctx.optlen, max_optlen)) != 0) {
 			ret = -EFAULT;
···
 		goto out;
 	}
 
-	if (ctx.optlen > max_optlen) {
+	if (ctx.optlen > max_optlen || ctx.optlen < 0) {
 		ret = -EFAULT;
 		goto out;
 	}

kernel/bpf/preload/Makefile

···
 LIBBPF_A = $(obj)/libbpf.a
 LIBBPF_OUT = $(abspath $(obj))
 
+# Although not in use by libbpf's Makefile, set $(O) so that the "dummy" test
+# in tools/scripts/Makefile.include always succeeds when building the kernel
+# with $(O) pointing to a relative path, as in "make O=build bindeb-pkg".
 $(LIBBPF_A):
-	$(Q)$(MAKE) -C $(LIBBPF_SRCS) OUTPUT=$(LIBBPF_OUT)/ $(LIBBPF_OUT)/libbpf.a
+	$(Q)$(MAKE) -C $(LIBBPF_SRCS) O=$(LIBBPF_OUT)/ OUTPUT=$(LIBBPF_OUT)/ $(LIBBPF_OUT)/libbpf.a
 
 userccflags += -I $(srctree)/tools/include/ -I $(srctree)/tools/include/uapi \
 	-I $(srctree)/tools/lib/ -Wno-unused-result