From: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Date: Fri, 1 Feb 2019 16:26:08 +0000 (+0000)
Subject: arm64: kexec_file: handle empty command-line
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=ea5736805190e912903c27c9f17c7a4341a405e9;p=linux.git

arm64: kexec_file: handle empty command-line

Calling strlen() on cmdline == NULL produces a kernel oops. Since having
a NULL cmdline is valid, handle this case explicitly.

Fixes: 52b2a8af7436 ("arm64: kexec_file: load initrd and device-tree")
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---

diff --git a/arch/arm64/kernel/machine_kexec_file.c b/arch/arm64/kernel/machine_kexec_file.c
index f2c211a6229ba..58871333737a4 100644
--- a/arch/arm64/kernel/machine_kexec_file.c
+++ b/arch/arm64/kernel/machine_kexec_file.c
@@ -120,10 +120,12 @@ static int create_dtb(struct kimage *image,
 {
 	void *buf;
 	size_t buf_size;
+	size_t cmdline_len;
 	int ret;
 
+	cmdline_len = cmdline ? strlen(cmdline) : 0;
 	buf_size = fdt_totalsize(initial_boot_params)
-			+ strlen(cmdline) + DTB_EXTRA_SPACE;
+			+ cmdline_len + DTB_EXTRA_SPACE;
 
 	for (;;) {
 		buf = vmalloc(buf_size);