The patch titled Subject: arm64: kexec: Initialize kexec_buf struct in image_load() has been added to the -mm mm-hotfixes-unstable branch. Its filename is arm64-kexec-initialize-kexec_buf-struct-in-image_load.patch
This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches...
This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------ From: Breno Leitao leitao@debian.org Subject: arm64: kexec: Initialize kexec_buf struct in image_load() Date: Tue, 26 Aug 2025 05:08:51 -0700
The kexec_buf structure was previously declared without initialization in image_load(). This led to a UBSAN warning when the structure was expanded and uninitialized fields were accessed [1].
Zero-initializing kexec_buf at declaration ensures all fields are cleanly set, preventing future instances of uninitialized memory being used.
Fixes this UBSAN warning:
[ 32.362488] UBSAN: invalid-load in ./include/linux/kexec.h:210:10 [ 32.362649] load of value 252 is not a valid value for type '_Bool'
Andrew Morton suggested that this function is only called 3x a week[2], thus, the memset() cost is inexpensive.
Link: https://lore.kernel.org/all/oninomspajhxp4omtdapxnckxydbk2nzmrix7rggmpukpnza... [1] Link: https://lore.kernel.org/all/20250825180531.94bfb86a26a43127c0a1296f@linux-fo... [2] Link: https://lkml.kernel.org/r/20250826-akpm-v1-1-3c831f0e3799@debian.org Fixes: bf454ec31add ("kexec_file: allow to place kexec_buf randomly") Signed-off-by: Breno Leitao leitao@debian.org Suggested-by: Andrew Morton akpm@linux-foundation.org Cc: Mark Rutland mark.rutland@arm.com Cc: Baoquan He bhe@redhat.com Cc: Coiby Xu coxu@redhat.com Cc: "Daniel P. Berrange" berrange@redhat.com Cc: Dave Hansen dave.hansen@intel.com Cc: Dave Young dyoung@redhat.com Cc: Kairui Song ryncsn@gmail.com Cc: Liu Pingfan kernelfans@gmail.com Cc: Milan Broz gmazyland@gmail.com Cc: Ondrej Kozina okozina@redhat.com Cc: Vitaly Kuznetsov vkuznets@redhat.com Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---
arch/arm64/kernel/kexec_image.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/arch/arm64/kernel/kexec_image.c~arm64-kexec-initialize-kexec_buf-struct-in-image_load +++ a/arch/arm64/kernel/kexec_image.c @@ -41,7 +41,7 @@ static void *image_load(struct kimage *i struct arm64_image_header *h; u64 flags, value; bool be_image, be_kernel; - struct kexec_buf kbuf; + struct kexec_buf kbuf = {}; unsigned long text_offset, kernel_segment_number; struct kexec_segment *kernel_segment; int ret; _
Patches currently in -mm which might be from leitao@debian.org are
arm64-kexec-initialize-kexec_buf-struct-in-image_load.patch