bpf: mark a NULL kfunc argument precisegrafted

check_kfunc_arg() allows bpf_register_is_null() for nullable arguments
w/o marking the underlying scalar register precise. Hence a checkpoint
created on such a path would prune against arbitrary scalar value.

Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 36 insertions, 0 deletions

diff --git a/include/uapi/asm-generic/Kbuild b/include/uapi/asm-generic/Kbuild
new file mode 100644
index 000000000..ebb180aac
--- /dev/null
+++ b/include/uapi/asm-generic/Kbuild
@@ -0,0 +1,36 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Headers that are mandatory in usr/include/asm/
+# (This file is not included when SRCARCH=um since UML does not support UAPI.)
+
+mandatory-y += auxvec.h
+mandatory-y += bitsperlong.h
+mandatory-y += bpf_perf_event.h
+mandatory-y += byteorder.h
+mandatory-y += errno.h
+mandatory-y += fcntl.h
+mandatory-y += ioctl.h
+mandatory-y += ioctls.h
+mandatory-y += ipcbuf.h
+mandatory-y += mman.h
+mandatory-y += msgbuf.h
+mandatory-y += param.h
+mandatory-y += poll.h
+mandatory-y += posix_types.h
+mandatory-y += ptrace.h
+mandatory-y += resource.h
+mandatory-y += sembuf.h
+mandatory-y += setup.h
+mandatory-y += shmbuf.h
+mandatory-y += sigcontext.h
+mandatory-y += siginfo.h
+mandatory-y += signal.h
+mandatory-y += socket.h
+mandatory-y += sockios.h
+mandatory-y += stat.h
+mandatory-y += statfs.h
+mandatory-y += swab.h
+mandatory-y += termbits.h
+mandatory-y += termios.h
+mandatory-y += types.h
+mandatory-y += unistd.h