FAILED: patch "[PATCH] riscv: kexec: initialize kexec_buf struct" failed to apply to 6.16-stable tree

FAILED: patch "[PATCH] riscv: kexec: initialize kexec_buf struct" failed to apply to 6.16-stable tree

[gregkh]

The patch below does not apply to the 6.16-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.16.y
git checkout FETCH_HEAD
git cherry-pick -x 8afbd0045922b8146acf1a78ae818693e0468dbd
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2025091310-tuition-parameter-2cd6@gregkh' --subject-prefix 'PATCH 6.16.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 8afbd0045922b8146acf1a78ae818693e0468dbd Mon Sep 17 00:00:00 2001
From: Breno Leitao <leitao@debian.org>
Date: Wed, 27 Aug 2025 03:42:22 -0700
Subject: [PATCH] riscv: kexec: initialize kexec_buf struct

The kexec_buf structure was previously declared without initialization.
commit bf454ec31add ("kexec_file: allow to place kexec_buf randomly")
added a field that is always read but not consistently populated by all
architectures. This un-initialized field will contain garbage.

This is also triggering a UBSAN warning when the uninitialized data was
accessed:

	------------[ cut here ]------------
	UBSAN: invalid-load in ./include/linux/kexec.h:210:10
	load of value 252 is not a valid value for type '_Bool'

Zero-initializing kexec_buf at declaration ensures all fields are
cleanly set, preventing future instances of uninitialized memory being
used.

Link: https://lkml.kernel.org/r/20250827-kbuf_all-v1-2-1df9882bb01a@debian.org
Fixes: bf454ec31add ("kexec_file: allow to place kexec_buf randomly")
Signed-off-by: Breno Leitao <leitao@debian.org>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Baoquan He <bhe@redhat.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Coiby Xu <coxu@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Will Deacon <will@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/arch/riscv/kernel/kexec_elf.c b/arch/riscv/kernel/kexec_elf.c
index 56444c7bd34e..531d348db84d 100644
--- a/arch/riscv/kernel/kexec_elf.c
+++ b/arch/riscv/kernel/kexec_elf.c
@@ -28,7 +28,7 @@ static int riscv_kexec_elf_load(struct kimage *image, struct elfhdr *ehdr,
 	int i;
 	int ret = 0;
 	size_t size;
-	struct kexec_buf kbuf;
+	struct kexec_buf kbuf = {};
 	const struct elf_phdr *phdr;
 
 	kbuf.image = image;
@@ -66,7 +66,7 @@ static int elf_find_pbase(struct kimage *image, unsigned long kernel_len,
 {
 	int i;
 	int ret;
-	struct kexec_buf kbuf;
+	struct kexec_buf kbuf = {};
 	const struct elf_phdr *phdr;
 	unsigned long lowest_paddr = ULONG_MAX;
 	unsigned long lowest_vaddr = ULONG_MAX;
diff --git a/arch/riscv/kernel/kexec_image.c b/arch/riscv/kernel/kexec_image.c
index 26a81774a78a..8f2eb900910b 100644
--- a/arch/riscv/kernel/kexec_image.c
+++ b/arch/riscv/kernel/kexec_image.c
@@ -41,7 +41,7 @@ static void *image_load(struct kimage *image,
 	struct riscv_image_header *h;
 	u64 flags;
 	bool be_image, be_kernel;
-	struct kexec_buf kbuf;
+	struct kexec_buf kbuf = {};
 	int ret;
 
 	/* Check Image header */
diff --git a/arch/riscv/kernel/machine_kexec_file.c b/arch/riscv/kernel/machine_kexec_file.c
index e36104af2e24..b9eb41b0a975 100644
--- a/arch/riscv/kernel/machine_kexec_file.c
+++ b/arch/riscv/kernel/machine_kexec_file.c
@@ -261,7 +261,7 @@ int load_extra_segments(struct kimage *image, unsigned long kernel_start,
 	int ret;
 	void *fdt;
 	unsigned long initrd_pbase = 0UL;
-	struct kexec_buf kbuf;
+	struct kexec_buf kbuf = {};
 	char *modified_cmdline = NULL;
 
 	kbuf.image = image;