From ea641be7a4faee4351f9c5ed6b188e1bbf5586a6 Mon Sep 17 00:00:00 2001 From: Jian Zhang Date: Fri, 3 Apr 2026 17:05:59 +0800 Subject: [PATCH] ipmi: ssif_bmc: fix missing check for copy_to_user() partial failure copy_to_user() returns the number of bytes that could not be copied, with a non-zero value indicating a partial or complete failure. The current code only checks for negative return values and treats all non-negative results as success. Treating any positive return value from copy_to_user() as an error and returning -EFAULT. Fixes: dd2bc5cc9e25 ("ipmi: ssif_bmc: Add SSIF BMC driver") Signed-off-by: Jian Zhang Message-ID: <20260403090603.3988423-2-zhangjian.3032@bytedance.com> Signed-off-by: Corey Minyard --- drivers/char/ipmi/ssif_bmc.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/char/ipmi/ssif_bmc.c b/drivers/char/ipmi/ssif_bmc.c index dc1d5bb4a4604..fbc7d2cfd5351 100644 --- a/drivers/char/ipmi/ssif_bmc.c +++ b/drivers/char/ipmi/ssif_bmc.c @@ -163,6 +163,8 @@ static ssize_t ssif_bmc_read(struct file *file, char __user *buf, size_t count, spin_unlock_irqrestore(&ssif_bmc->lock, flags); ret = copy_to_user(buf, &msg, count); + if (ret > 0) + ret = -EFAULT; } return (ret < 0) ? ret : count; -- 2.47.3