From: Thorsten Blum <thorsten.blum@linux.dev>
To: Borislav Petkov <bp@alien8.de>
Cc: Thomas Gleixner <tglx@kernel.org>, Ingo Molnar <mingo@redhat.com>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] x86/boot: Reject truncated acpi_rsdp= values
Date: Fri, 19 Jun 2026 09:57:58 +0200 [thread overview]
Message-ID: <ajT2hnSb7o7SMyLU@linux.dev> (raw)
In-Reply-To: <20260619024814.GIajSt7h4E7GXlsO5U@fat_crate.local>
On Thu, Jun 18, 2026 at 07:48:14PM -0700, Borislav Petkov wrote:
> On Fri, Jun 19, 2026 at 03:00:54AM +0200, Thorsten Blum wrote:
> > You can reproduce this with QEMU using the malformed example from
> > before:
> >
> > acpi_rsdp=0x0123456789abcdefx
>
> I just did: it says
>
> [ 0.000000] Malformed early option 'acpi_rsdp'
>
> with latest Linus tree without your patch.
>
> That's because that comes from setup_acpi_rsdp() which calls kstrtoul().
>
> I doubt you even hit get_cmdline_acpi_rsdp() as that's the decompressor legacy
> path and modern machines boot through the EFI stub like my guest does...
Are you perhaps appending nokaslr?
With the latest Linus tree, defconfig, and CONFIG_MEMORY_HOTREMOVE=y,
this crashes reproducibly for me, but only when KASLR is not disabled:
qemu-system-x86_64 -nographic -no-reboot -kernel arch/x86/boot/bzImage -append "console=ttyS0 acpi_rsdp=0x0123456789abcdefx"
next prev parent reply other threads:[~2026-06-19 7:58 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-06-17 13:04 [PATCH] x86/boot: Reject truncated acpi_rsdp= values Thorsten Blum
2026-06-18 4:54 ` Borislav Petkov
2026-06-18 15:03 ` Thorsten Blum
2026-06-18 16:38 ` Borislav Petkov
2026-06-18 17:59 ` Thorsten Blum
2026-06-18 18:04 ` Borislav Petkov
2026-06-18 18:57 ` Thorsten Blum
2026-06-18 19:34 ` Borislav Petkov
2026-06-19 1:00 ` Thorsten Blum
2026-06-19 2:48 ` Borislav Petkov
2026-06-19 7:57 ` Thorsten Blum [this message]
2026-06-19 20:24 ` Borislav Petkov
2026-06-19 21:43 ` Thorsten Blum
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