This is a note to let you know that I've just added the patch titled
tracing: Prevent bad count for tracing_cpumask_write
to the 5.10-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:
tracing-prevent-bad-count-for-tracing_cpumask_write.patch
and it can be found in the queue-5.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit b3d02b31e729480f8a58c3562f7f8a932725a29d
Author: Lizhi Xu <lizhi.xu@xxxxxxxxxxxxx>
Date: Mon Dec 16 15:32:38 2024 +0800
tracing: Prevent bad count for tracing_cpumask_write
[ Upstream commit 98feccbf32cfdde8c722bc4587aaa60ee5ac33f0 ]
If a large count is provided, it will trigger a warning in bitmap_parse_user.
Also check zero for it.
Cc: stable@xxxxxxxxxxxxxxx
Fixes: 9e01c1b74c953 ("cpumask: convert kernel trace functions")
Link: https://lore.kernel.org/20241216073238.2573704-1-lizhi.xu@xxxxxxxxxxxxx
Reported-by: syzbot+0aecfd34fb878546f3fd@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=0aecfd34fb878546f3fd
Tested-by: syzbot+0aecfd34fb878546f3fd@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Lizhi Xu <lizhi.xu@xxxxxxxxxxxxx>
Signed-off-by: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 3ecd7c700579..ca39a647f2ef 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -4910,6 +4910,9 @@ 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;
