diff options
author | Alexander Potapenko <glider@google.com> | 2022-11-02 12:06:11 +0100 |
---|---|---|
committer | Andrew Morton <akpm@linux-foundation.org> | 2022-11-08 15:57:24 -0800 |
commit | ba54d194f8daad8943802d6dfe06e205f882c391 (patch) | |
tree | f0b6971ef0ef09d4a5ffa01ab24c8885d2478aa7 /arch/x86/kernel/traps.c | |
parent | 83d0edfa04eeca46b3eff554fb42b2fefe97bdf1 (diff) | |
download | linux-stable-ba54d194f8daad8943802d6dfe06e205f882c391.tar.gz linux-stable-ba54d194f8daad8943802d6dfe06e205f882c391.tar.bz2 linux-stable-ba54d194f8daad8943802d6dfe06e205f882c391.zip |
x86/traps: avoid KMSAN bugs originating from handle_bug()
There is a case in exc_invalid_op handler that is executed outside the
irqentry_enter()/irqentry_exit() region when an UD2 instruction is used to
encode a call to __warn().
In that case the `struct pt_regs` passed to the interrupt handler is never
unpoisoned by KMSAN (this is normally done in irqentry_enter()), which
leads to false positives inside handle_bug().
Use kmsan_unpoison_entry_regs() to explicitly unpoison those registers
before using them.
Link: https://lkml.kernel.org/r/20221102110611.1085175-5-glider@google.com
Signed-off-by: Alexander Potapenko <glider@google.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Marco Elver <elver@google.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Nick Desaulniers <ndesaulniers@google.com>
Cc: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'arch/x86/kernel/traps.c')
-rw-r--r-- | arch/x86/kernel/traps.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index 178015a820f0..d3fdec706f1d 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -15,6 +15,7 @@ #include <linux/context_tracking.h> #include <linux/interrupt.h> #include <linux/kallsyms.h> +#include <linux/kmsan.h> #include <linux/spinlock.h> #include <linux/kprobes.h> #include <linux/uaccess.h> @@ -301,6 +302,12 @@ static noinstr bool handle_bug(struct pt_regs *regs) { bool handled = false; + /* + * Normally @regs are unpoisoned by irqentry_enter(), but handle_bug() + * is a rare case that uses @regs without passing them to + * irqentry_enter(). + */ + kmsan_unpoison_entry_regs(regs); if (!is_valid_bugaddr(regs->ip)) return handled; |