The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 98feccbf32cfdde8c722bc4587aaa60ee5ac33f0 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024123047-unfounded-coil-47c5@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 98feccbf32cfdde8c722bc4587aaa60ee5ac33f0 Mon Sep 17 00:00:00 2001 From: Lizhi Xu lizhi.xu@windriver.com Date: Mon, 16 Dec 2024 15:32:38 +0800 Subject: [PATCH] tracing: Prevent bad count for tracing_cpumask_write

If a large count is provided, it will trigger a warning in bitmap_parse_user. Also check zero for it.

Cc: stable@vger.kernel.org Fixes: 9e01c1b74c953 ("cpumask: convert kernel trace functions") Link: https://lore.kernel.org/20241216073238.2573704-1-lizhi.xu@windriver.com 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 Signed-off-by: Steven Rostedt (Google) rostedt@goodmis.org

diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 957f941a08e7..f8aebcb01e62 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5087,6 +5087,9 @@ 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;