Re: [syzbot] [kernel?] KASAN: stack-out-of-bounds Read in __show_regs (2)

[Hillf Danton]

On Thu, 01 Aug 2024 16:39:23 -0700
> syzbot has found a reproducer for the following issue on:
> 
> HEAD commit:    931a3b3bccc9 Add linux-next specific files for 20240729
> git tree:       linux-next
> C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=10f437f1980000

Test Tetsuo's idea [1].
[1] https://lore.kernel.org/lkml/5136bcc7-3db7-4fc2-abde-a3aceeaf17c2@xxxxxxxxxxxxxxxxxxx/

#syz test linux-next  931a3b3bccc9

--- x/arch/x86/kernel/dumpstack.c
+++ y/arch/x86/kernel/dumpstack.c
@@ -192,6 +192,7 @@ static void show_trace_log_lvl(struct ta
 	int graph_idx = 0;
 	bool partial = false;
 
+	kasan_disable_current();
 	printk("%sCall Trace:\n", log_lvl);
 
 	unwind_start(&state, task, regs, stack);
@@ -304,6 +305,7 @@ next:
 		if (stack_name)
 			printk("%s </%s>\n", log_lvl, stack_name);
 	}
+	kasan_enable_current();
 }
 
 void show_stack(struct task_struct *task, unsigned long *sp,
--