Gentle ping in case of forgotten.

On Mon, Dec 01, 2025 at 10:51:18AM +0000, Yeoreum Yun wrote:

Commit bf454ec31add ("kexec_file: allow to place kexec_buf randomly") introduced the kexec_buf->random field to enable random placement of kexec_buf.

However, this field was never properly initialized for kexec images that do not need to be placed randomly, leading to the following UBSAN warning:

[ +0.364528] ------------[ cut here ]------------ [ +0.000019] UBSAN: invalid-load in ./include/linux/kexec.h:210:12 [ +0.000131] load of value 2 is not a valid value for type 'bool' (aka '_Bool') [ +0.000003] CPU: 4 UID: 0 PID: 927 Comm: kexec Not tainted 6.18.0-rc7+ #3 PREEMPT(full) [ +0.000002] Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015 [ +0.000000] Call trace: [ +0.000001] show_stack+0x24/0x40 (C) [ +0.000006] __dump_stack+0x28/0x48 [ +0.000002] dump_stack_lvl+0x7c/0xb0 [ +0.000002] dump_stack+0x18/0x34 [ +0.000001] ubsan_epilogue+0x10/0x50 [ +0.000002] __ubsan_handle_load_invalid_value+0xc8/0xd0 [ +0.000003] locate_mem_hole_callback+0x28c/0x2a0 [ +0.000003] kexec_locate_mem_hole+0xf4/0x2f0 [ +0.000001] kexec_add_buffer+0xa8/0x178 [ +0.000002] image_load+0xf0/0x258 [ +0.000001] __arm64_sys_kexec_file_load+0x510/0x718 [ +0.000002] invoke_syscall+0x68/0xe8 [ +0.000001] el0_svc_common+0xb0/0xf8 [ +0.000002] do_el0_svc+0x28/0x48 [ +0.000001] el0_svc+0x40/0xe8 [ +0.000002] el0t_64_sync_handler+0x84/0x140 [ +0.000002] el0t_64_sync+0x1bc/0x1c0

To address this, initialise kexec_buf->random field properly.

Fixes: bf454ec31add ("kexec_file: allow to place kexec_buf randomly") Suggested-by: Breno Leitao leitao@debian.org Cc: stable@vger.kernel.org Signed-off-by: Yeoreum Yun yeoreum.yun@arm.com

---

arch/arm64/kernel/kexec_image.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/arm64/kernel/kexec_image.c b/arch/arm64/kernel/kexec_image.c index 532d72ea42ee..b70f4df15a1a 100644 --- a/arch/arm64/kernel/kexec_image.c +++ b/arch/arm64/kernel/kexec_image.c @@ -41,7 +41,7 @@ static void *image_load(struct kimage *image, 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;

-- LEVI:{C3F47F37-75D8-414A-A8BA-3980EC8A46D7}

-- Sincerely, Yeoreum Yun