This is a note to let you know that I've just added the patch titled
riscv: Avoid enabling interrupts in die()
to the 6.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
riscv-avoid-enabling-interrupts-in-die.patch
and it can be found in the queue-6.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 130aee3fd9981297ff9354e5d5609cd59aafbbea Mon Sep 17 00:00:00 2001
From: Mattias Nissler <mnissler@xxxxxxxxxxxx>
Date: Wed, 15 Feb 2023 14:48:28 +0000
Subject: riscv: Avoid enabling interrupts in die()
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From: Mattias Nissler <mnissler@xxxxxxxxxxxx>
commit 130aee3fd9981297ff9354e5d5609cd59aafbbea upstream.
While working on something else, I noticed that the kernel would start
accepting interrupts again after crashing in an interrupt handler. Since
the kernel is already in inconsistent state, enabling interrupts is
dangerous and opens up risk of kernel state deteriorating further.
Interrupts do get enabled via what looks like an unintended side effect of
spin_unlock_irq, so switch to the more cautious
spin_lock_irqsave/spin_unlock_irqrestore instead.
Fixes: 76d2a0493a17 ("RISC-V: Init and Halt Code")
Signed-off-by: Mattias Nissler <mnissler@xxxxxxxxxxxx>
Reviewed-by: Björn Töpel <bjorn@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230215144828.3370316-1-mnissler@xxxxxxxxxxxx
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/riscv/kernel/traps.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
--- a/arch/riscv/kernel/traps.c
+++ b/arch/riscv/kernel/traps.c
@@ -34,10 +34,11 @@ void die(struct pt_regs *regs, const cha
static int die_counter;
int ret;
long cause;
+ unsigned long flags;
oops_enter();
- spin_lock_irq(&die_lock);
+ spin_lock_irqsave(&die_lock, flags);
console_verbose();
bust_spinlocks(1);
@@ -54,7 +55,7 @@ void die(struct pt_regs *regs, const cha
bust_spinlocks(0);
add_taint(TAINT_DIE, LOCKDEP_NOW_UNRELIABLE);
- spin_unlock_irq(&die_lock);
+ spin_unlock_irqrestore(&die_lock, flags);
oops_exit();
if (in_interrupt())
Patches currently in stable-queue which might be from mnissler@xxxxxxxxxxxx are
queue-6.2/riscv-avoid-enabling-interrupts-in-die.patch
