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.

Fixes: bf454ec31add ("kexec_file: allow to place kexec_buf randomly")
Signed-off-by: Breno Leitao <leitao@debian.org>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20250827-kbuf_all-v1-2-1df9882bb01a@debian.org
Signed-off-by: Paul Walmsley <pjw@kernel.org>

diff --git a/arch/riscv/kernel/kexec_elf.c b/arch/riscv/kernel/kexec_elf.c
index 56444c7bd34eb11f7e70223715b343f7de1ff5ef..531d348db84d73cbeb87ae42f01248672259c129 100644 (file)
--- 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 26a81774a78a36f05f3252d71edba16fd2d3b96f..8f2eb900910b1434045ff68b123457afe36bf309 100644 (file)
--- 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 e36104af2e247fc0acb88eb5558d07ac49c713e4..b9eb41b0a975192c1395202074f54c751e818b30 100644 (file)
--- 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;