From: Nicholas Piggin npiggin@gmail.com
[ Upstream commit 001c28e57187570e4b5aa4492c7a957fb6d65d7b ]
If a task oopses with irqs disabled, this can cause various cascading problems in the oops path such as sleep-from-invalid warnings, and potentially worse.
Since commit 0258b5fd7c712 ("coredump: Limit coredumps to a single thread group"), the unconditional irq enable in coredump_task_exit() will "fix" the irq state to be enabled early in do_exit(), so currently this may not be triggerable, but that is coincidental and fragile.
Detect and fix the irqs_disabled() condition in the oops path before calling do_exit(), similarly to the way in_atomic() is handled.
Reported-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Nicholas Piggin npiggin@gmail.com Signed-off-by: Peter Zijlstra (Intel) peterz@infradead.org Acked-by: "Eric W. Biederman" ebiederm@xmission.com Link: https://lore.kernel.org/lkml/20221004094401.708299-1-npiggin@gmail.com/ Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/exit.c | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/kernel/exit.c b/kernel/exit.c index 15dc2ec80c467..bccfa4218356e 100644 --- a/kernel/exit.c +++ b/kernel/exit.c @@ -807,6 +807,8 @@ void __noreturn do_exit(long code) struct task_struct *tsk = current; int group_dead;
+ WARN_ON(irqs_disabled()); + synchronize_group_exit(tsk, code);
WARN_ON(tsk->plug); @@ -938,6 +940,11 @@ void __noreturn make_task_dead(int signr) if (unlikely(!tsk->pid)) panic("Attempted to kill the idle task!");
+ if (unlikely(irqs_disabled())) { + pr_info("note: %s[%d] exited with irqs disabled\n", + current->comm, task_pid_nr(current)); + local_irq_enable(); + } if (unlikely(in_atomic())) { pr_info("note: %s[%d] exited with preempt_count %d\n", current->comm, task_pid_nr(current),