From 215368e8e59023d6a0abdda896923018d74fdf7f Mon Sep 17 00:00:00 2001 From: Li Zefan Date: Mon, 15 Jun 2009 10:56:42 +0800 Subject: [PATCH] tracing: fix a typo in tracing_cpumask_write() It's tracing_cpumask_new that should be kfree()ed. This causes tracing_cpumask to be freed due to the typo: # echo z > tracing_cpumask bash: echo: write error: Invalid argument And subsequent reads/writes to tracing_cpuamsk will access this already-freed tracing_cpumask, thus may lead to crash. [ Impact: fix leak and crash when writing invalid val to tracing_cpumask ] Acked-by: Frederic Weisbecker Signed-off-by: Li Zefan LKML-Reference: <4A35B86A.7070608@cn.fujitsu.com> Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8acd9b81a5d7..7355a38e18be 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -2191,11 +2191,12 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf, if (!alloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL)) return -ENOMEM; - mutex_lock(&tracing_cpumask_update_lock); err = cpumask_parse_user(ubuf, count, tracing_cpumask_new); if (err) goto err_unlock; + mutex_lock(&tracing_cpumask_update_lock); + local_irq_disable(); __raw_spin_lock(&ftrace_max_lock); for_each_tracing_cpu(cpu) { @@ -2223,8 +2224,7 @@ tracing_cpumask_write(struct file *filp, const char __user *ubuf, return count; err_unlock: - mutex_unlock(&tracing_cpumask_update_lock); - free_cpumask_var(tracing_cpumask); + free_cpumask_var(tracing_cpumask_new); return err; } -- GitLab