diff mbox series

[V2] tracing: Prevent bad count for tracing_cpumask_write

Message ID 20241216073238.2573704-1-lizhi.xu@windriver.com (mailing list archive)
State New
Headers show
Series [V2] tracing: Prevent bad count for tracing_cpumask_write | expand

Commit Message

Lizhi Xu Dec. 16, 2024, 7:32 a.m. UTC 
If a large count is provided, it will triger a warning in bitmap_parse_user.
Also check zero for it.

Reported-by: syzbot+0aecfd34fb878546f3fd@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=0aecfd34fb878546f3fd
Tested-by: syzbot+0aecfd34fb878546f3fd@syzkaller.appspotmail.com
Signed-off-by: Lizhi Xu <lizhi.xu@windriver.com>
---
V1 -> V2: use KMALLOC_MAX_SIZE

 kernel/trace/trace.c | 3 +++
 1 file changed, 3 insertions(+)
diff mbox series

Patch

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index be62f0ea1814..109f301549b8 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -5225,6 +5225,9 @@  tracing_cpumask_write(struct file *filp, const char __user *ubuf,
 	cpumask_var_t tracing_cpumask_new;
 	int err;
 
+	if (count == 0 || count > KMALLOC_MAX_SIZE)
+		return -EINVAL;
+
 	if (!zalloc_cpumask_var(&tracing_cpumask_new, GFP_KERNEL))
 		return -ENOMEM;