Messages in this thread Patch in this message | | | From | Ashok Raj <> | Subject | [Patch v3 Part2 2/9] x86/microcode: Report invalid writes to reload sysfs file | Date | Mon, 30 Jan 2023 13:39:48 -0800 |
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Semantics of the microcode reload file are only defined if a "1" is written. But the code silently treats any other unsigned integer as a successful write even though no actions are performed to load microcode.
Report those erroneous writes back to user.
Suggested-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ashok Raj <ashok.raj@intel.com> Cc: LKML <linux-kernel@vger.kernel.org> Cc: x86 <x86@kernel.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Tony Luck <tony.luck@intel.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Alison Schofield <alison.schofield@intel.com> Cc: Reinette Chatre <reinette.chatre@intel.com> Cc: Thomas Gleixner (Intel) <tglx@linutronix.de> Cc: Tom Lendacky <thomas.lendacky@amd.com> Cc: Stefan Talpalaru <stefantalpalaru@yahoo.com> Cc: David Woodhouse <dwmw2@infradead.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Rafael J. Wysocki <rafael@kernel.org> Cc: Peter Zilstra (Intel) <peterz@infradead.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Andrew Cooper <Andrew.Cooper3@citrix.com> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Martin Pohlack <mpohlack@amazon.de> --- arch/x86/kernel/cpu/microcode/core.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-)
diff --git a/arch/x86/kernel/cpu/microcode/core.c b/arch/x86/kernel/cpu/microcode/core.c index 1c6831b8b244..e4b4dfcf2d18 100644 --- a/arch/x86/kernel/cpu/microcode/core.c +++ b/arch/x86/kernel/cpu/microcode/core.c @@ -476,11 +476,8 @@ static ssize_t reload_store(struct device *dev, ssize_t ret; ret = kstrtoul(buf, 0, &val); - if (ret) - return ret; - - if (val != 1) - return size; + if (ret || val != 1) + return -EINVAL; cpus_read_lock(); -- 2.37.2
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