From ed0f298a929283947ffbe5ac24ea3a7cef898b3f Mon Sep 17 00:00:00 2001 From: Lizhi Xu Date: Mon, 16 Dec 2024 15:32:38 +0800 Subject: [PATCH] tracing: Prevent bad count for tracing_cpumask_write BugLink: https://bugs.launchpad.net/bugs/2103869 commit 98feccbf32cfdde8c722bc4587aaa60ee5ac33f0 upstream. 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 Signed-off-by: Steven Rostedt (Google) Signed-off-by: Greg Kroah-Hartman CVE-2024-56763 Signed-off-by: Manuel Diewald Signed-off-by: Mehmet Basaran --- kernel/trace/trace.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index f11eac9a86d4..5c6988494b74 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -5352,6 +5352,9 @@ 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;