From: Arnaud Lecomte <contact@arnaud-lcm.com>
To: abbotti@mev.co.uk, hsweeten@visionengravers.com,
gregkh@linuxfoundation.org,
syzbot+a5e45f768aab5892da5d@syzkaller.appspotmail.com
Cc: contact@arnaud-lcm.com, jannh@google.com,
linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com
Subject: [PATCH] comedi: zero-init data in do_insn_ioctl
Date: Thu, 24 Jul 2025 22:04:51 +0100 [thread overview]
Message-ID: <20250724210451.108177-1-contact@arnaud-lcm.com> (raw)
KMSAN reported a kernel-infoleak when copying instruction data back to
userspace in do_insnlist_ioctl(). The issue occurs because allocated
memory buffers weren't properly initialized (not
zero initialized) before being copied to
userspace, potentially leaking kernel memory.
Reported-by: syzbot+a5e45f768aab5892da5d@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=a5e45f768aab5892da5d
Tested-by: syzbot+a5e45f768aab5892da5d@syzkaller.appspotmail.com
Signed-off-by: Arnaud Lecomte <contact@arnaud-lcm.com>
---
drivers/comedi/comedi_fops.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/comedi/comedi_fops.c b/drivers/comedi/comedi_fops.c
index c83fd14dd7ad..15fee829d14c 100644
--- a/drivers/comedi/comedi_fops.c
+++ b/drivers/comedi/comedi_fops.c
@@ -1636,7 +1636,7 @@ static int do_insn_ioctl(struct comedi_device *dev,
n_data = MAX_SAMPLES;
}
- data = kmalloc_array(n_data, sizeof(unsigned int), GFP_KERNEL);
+ data = kcalloc(n_data, sizeof(unsigned int), GFP_KERNEL);
if (!data) {
ret = -ENOMEM;
goto error;
--
2.43.0
next reply other threads:[~2025-07-24 21:05 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-24 21:04 Arnaud Lecomte [this message]
2025-07-25 9:41 ` Ian Abbott
2025-07-25 9:43 ` Lecomte, Arnaud
2025-07-25 10:04 ` Ian Abbott
2025-07-25 10:06 ` Lecomte, Arnaud
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