arch/arm64/kernel/machine_kexec_file.c | 2 +- arch/riscv/kernel/kexec_elf.c | 4 ++-- arch/riscv/kernel/kexec_image.c | 2 +- arch/riscv/kernel/machine_kexec_file.c | 2 +- arch/s390/kernel/kexec_elf.c | 2 +- arch/s390/kernel/kexec_image.c | 2 +- arch/s390/kernel/machine_kexec_file.c | 6 +++--- 7 files changed, 10 insertions(+), 10 deletions(-)
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.
An initial fix was already landed for arm64[0], and this patchset fixes
the problem on the remaining arm64 code and on riscv, as raised by Mark.
Discussions about this problem could be found at[1][2].
Link: https://lore.kernel.org/all/20250826180742.f2471131255ec1c43683ea07@linux-foundation.org/ [0]
Link: https://lore.kernel.org/all/oninomspajhxp4omtdapxnckxydbk2nzmrix7rggmpukpnzadw@c67o7njgdgm3/ [1]
Link: https://lore.kernel.org/all/20250826-akpm-v1-1-3c831f0e3799@debian.org/ [2]
Signed-off-by: Breno Leitao <leitao@debian.org>
---
Breno Leitao (3):
arm64: kexec: Initialize kexec_buf struct in load_other_segments()
riscv: kexec: Initialize kexec_buf struct
s390: kexec: Initialize kexec_buf struct
arch/arm64/kernel/machine_kexec_file.c | 2 +-
arch/riscv/kernel/kexec_elf.c | 4 ++--
arch/riscv/kernel/kexec_image.c | 2 +-
arch/riscv/kernel/machine_kexec_file.c | 2 +-
arch/s390/kernel/kexec_elf.c | 2 +-
arch/s390/kernel/kexec_image.c | 2 +-
arch/s390/kernel/machine_kexec_file.c | 6 +++---
7 files changed, 10 insertions(+), 10 deletions(-)
---
base-commit: 3c642997252eef4449cb6b6e02af3dc22515d817
change-id: 20250827-kbuf_all-b9d55c9291eb
Best regards,
--
Breno Leitao <leitao@debian.org>
Hi Breno,
On 8/27/25 12:42, Breno Leitao wrote:
> 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.
>
> An initial fix was already landed for arm64[0], and this patchset fixes
> the problem on the remaining arm64 code and on riscv, as raised by Mark.
>
> Discussions about this problem could be found at[1][2].
>
> Link: https://lore.kernel.org/all/20250826180742.f2471131255ec1c43683ea07@linux-foundation.org/ [0]
> Link: https://lore.kernel.org/all/oninomspajhxp4omtdapxnckxydbk2nzmrix7rggmpukpnzadw@c67o7njgdgm3/ [1]
> Link: https://lore.kernel.org/all/20250826-akpm-v1-1-3c831f0e3799@debian.org/ [2]
>
> Signed-off-by: Breno Leitao <leitao@debian.org>
> ---
> Breno Leitao (3):
> arm64: kexec: Initialize kexec_buf struct in load_other_segments()
> riscv: kexec: Initialize kexec_buf struct
> s390: kexec: Initialize kexec_buf struct
>
> arch/arm64/kernel/machine_kexec_file.c | 2 +-
> arch/riscv/kernel/kexec_elf.c | 4 ++--
> arch/riscv/kernel/kexec_image.c | 2 +-
> arch/riscv/kernel/machine_kexec_file.c | 2 +-
> arch/s390/kernel/kexec_elf.c | 2 +-
> arch/s390/kernel/kexec_image.c | 2 +-
> arch/s390/kernel/machine_kexec_file.c | 6 +++---
> 7 files changed, 10 insertions(+), 10 deletions(-)
> ---
> base-commit: 3c642997252eef4449cb6b6e02af3dc22515d817
> change-id: 20250827-kbuf_all-b9d55c9291eb
>
> Best regards,
> --
> Breno Leitao <leitao@debian.org>
I see that the commit those patches fix is in 6.16 so we should add cc:
stable.
And who should merge those patches? Should we do it on a per-arch basis?
Thanks,
Alex
>
> _______________________________________________
> linux-riscv mailing list
> linux-riscv@lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-riscv
On 09/01/25 at 08:42am, Alexandre Ghiti wrote: > Hi Breno, > > On 8/27/25 12:42, Breno Leitao wrote: .....snip... > > I see that the commit those patches fix is in 6.16 so we should add cc: > stable. > > And who should merge those patches? Should we do it on a per-arch basis? It's been in Andrew's akpm-mm/mm-hotfixes-unstable.
Hi Baoquan, On 9/1/25 11:02, Baoquan He wrote: > On 09/01/25 at 08:42am, Alexandre Ghiti wrote: >> Hi Breno, >> >> On 8/27/25 12:42, Breno Leitao wrote: > .....snip... >> I see that the commit those patches fix is in 6.16 so we should add cc: >> stable. >> >> And who should merge those patches? Should we do it on a per-arch basis? > It's been in Andrew's akpm-mm/mm-hotfixes-unstable. Great, thanks for letting me know. Alex >
On 08/27/25 at 03:42am, Breno Leitao wrote:
> 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.
>
> An initial fix was already landed for arm64[0], and this patchset fixes
> the problem on the remaining arm64 code and on riscv, as raised by Mark.
>
> Discussions about this problem could be found at[1][2].
>
> Link: https://lore.kernel.org/all/20250826180742.f2471131255ec1c43683ea07@linux-foundation.org/ [0]
> Link: https://lore.kernel.org/all/oninomspajhxp4omtdapxnckxydbk2nzmrix7rggmpukpnzadw@c67o7njgdgm3/ [1]
> Link: https://lore.kernel.org/all/20250826-akpm-v1-1-3c831f0e3799@debian.org/ [2]
>
> Signed-off-by: Breno Leitao <leitao@debian.org>
> ---
> Breno Leitao (3):
> arm64: kexec: Initialize kexec_buf struct in load_other_segments()
> riscv: kexec: Initialize kexec_buf struct
> s390: kexec: Initialize kexec_buf struct
Thanks for the fix, all looks good to me.
Acked-by: Baoquan He <bhe@redhat.com>
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