* + arm64-kernel-initialize-missing-kexec_buf-random-field.patch added to mm-hotfixes-unstable branch
@ 2026-01-03 17:25 Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2026-01-03 17:25 UTC (permalink / raw)
To: mm-commits, will, stable, mark.rutland, leitao, coxu,
catalin.marinas, yeoreum.yun, akpm
The patch titled
Subject: arm64: kernel: initialize missing kexec_buf->random field
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
arm64-kernel-initialize-missing-kexec_buf-random-field.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/arm64-kernel-initialize-missing-kexec_buf-random-field.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via various
branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there most days
------------------------------------------------------
From: Yeoreum Yun <yeoreum.yun@arm.com>
Subject: arm64: kernel: initialize missing kexec_buf->random field
Date: Mon, 1 Dec 2025 10:51:18 +0000
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.
Link: https://lkml.kernel.org/r/20251201105118.2786335-1-yeoreum.yun@arm.com
Fixes: bf454ec31add ("kexec_file: allow to place kexec_buf randomly")
Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Suggested-by: Breno Leitao <leitao@debian.org>
Reviewed-by: Breno Leitao <leitao@debian.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Coiby Xu <coxu@redhat.com>
Cc: levi.yun <yeoreum.yun@arm.com>
Cc: Marc Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
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-kernel-initialize-missing-kexec_buf-random-field
+++ 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 yeoreum.yun@arm.com are
arm64-kernel-initialize-missing-kexec_buf-random-field.patch
^ permalink raw reply [flat|nested] 2+ messages in thread* + arm64-kernel-initialize-missing-kexec_buf-random-field.patch added to mm-hotfixes-unstable branch
@ 2025-11-27 19:37 Andrew Morton
0 siblings, 0 replies; 2+ messages in thread
From: Andrew Morton @ 2025-11-27 19:37 UTC (permalink / raw)
To: mm-commits, will, stable, leitao, jpazdziora, coxu,
catalin.marinas, bhe, yeoreum.yun, akpm
The patch titled
Subject: arm64: kernel: initialize missing kexec_buf->random field
has been added to the -mm mm-hotfixes-unstable branch. Its filename is
arm64-kernel-initialize-missing-kexec_buf-random-field.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/arm64-kernel-initialize-missing-kexec_buf-random-field.patch
This patch will later appear in the mm-hotfixes-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Before you just go and hit "reply", please:
a) Consider who else should be cc'ed
b) Prefer to cc a suitable mailing list as well
c) Ideally: find the original patch on the mailing list and do a
reply-to-all to that, adding suitable additional cc's
*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***
The -mm tree is included into linux-next via the mm-everything
branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
and is updated there every 2-3 working days
------------------------------------------------------
From: Yeoreum Yun <yeoreum.yun@arm.com>
Subject: arm64: kernel: initialize missing kexec_buf->random field
Date: Thu, 27 Nov 2025 18:26:44 +0000
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.
Link: https://lkml.kernel.org/r/20251127182644.1577592-1-yeoreum.yun@arm.com
Fixes: bf454ec31add ("kexec_file: allow to place kexec_buf randomly")
Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Breno Leitao <leitao@debian.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Coiby Xu <coxu@redhat.com>
Cc: levi.yun <yeoreum.yun@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Jan Pazdziora <jpazdziora@redhat.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
arch/arm64/kernel/kexec_image.c | 3 +++
arch/arm64/kernel/machine_kexec_file.c | 6 +++++-
2 files changed, 8 insertions(+), 1 deletion(-)
--- a/arch/arm64/kernel/kexec_image.c~arm64-kernel-initialize-missing-kexec_buf-random-field
+++ a/arch/arm64/kernel/kexec_image.c
@@ -76,6 +76,9 @@ static void *image_load(struct kimage *i
kbuf.buf_min = 0;
kbuf.buf_max = ULONG_MAX;
kbuf.top_down = false;
+#ifdef CONFIG_CRASH_DUMP
+ kbuf.random = false;
+#endif
kbuf.buffer = kernel;
kbuf.bufsz = kernel_len;
--- a/arch/arm64/kernel/machine_kexec_file.c~arm64-kernel-initialize-missing-kexec_buf-random-field
+++ a/arch/arm64/kernel/machine_kexec_file.c
@@ -94,7 +94,11 @@ int load_other_segments(struct kimage *i
char *initrd, unsigned long initrd_len,
char *cmdline)
{
- struct kexec_buf kbuf = {};
+ struct kexec_buf kbuf = {
+#ifdef CONFIG_CRASH_DUMP
+ .random = false,
+#endif
+ };
void *dtb = NULL;
unsigned long initrd_load_addr = 0, dtb_len,
orig_segments = image->nr_segments;
_
Patches currently in -mm which might be from yeoreum.yun@arm.com are
arm64-kernel-initialize-missing-kexec_buf-random-field.patch
^ permalink raw reply [flat|nested] 2+ messages in thread
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2025-11-27 19:37 Andrew Morton
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