This is a note to let you know that I've just added the patch titled ipmi: ssif_bmc: prevent integer overflow on 32bit systems to the 6.10-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: ipmi-ssif_bmc-prevent-integer-overflow-on-32bit-syst.patch and it can be found in the queue-6.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 033ce8a77f7e3b53b3a132eed8694f2f37f474b2 Author: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Date: Fri Jun 14 20:30:44 2024 +0300 ipmi: ssif_bmc: prevent integer overflow on 32bit systems [ Upstream commit 0627cef36145c9ff9845bdfd7ddf485bbac1f981 ] There are actually two bugs here. First, we need to ensure that count is at least sizeof(u32) or msg.len will be uninitialized data. The "msg.len" variable is a u32 that comes from the user. On 32bit systems the "sizeof_field(struct ipmi_ssif_msg, len) + msg.len" addition can overflow if "msg.len" is greater than U32_MAX - 4. Valid lengths for "msg.len" are 1-254. Add a check for that to prevent the integer overflow. Fixes: dd2bc5cc9e25 ("ipmi: ssif_bmc: Add SSIF BMC driver") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Message-Id: <1431ca2e-4e9c-4520-bfc0-6879313c30e9@moroto.mountain> Signed-off-by: Corey Minyard <corey@xxxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/char/ipmi/ssif_bmc.c b/drivers/char/ipmi/ssif_bmc.c index 56346fb328727..ab4e87a99f087 100644 --- a/drivers/char/ipmi/ssif_bmc.c +++ b/drivers/char/ipmi/ssif_bmc.c @@ -177,13 +177,15 @@ static ssize_t ssif_bmc_write(struct file *file, const char __user *buf, size_t unsigned long flags; ssize_t ret; - if (count > sizeof(struct ipmi_ssif_msg)) + if (count < sizeof(msg.len) || + count > sizeof(struct ipmi_ssif_msg)) return -EINVAL; if (copy_from_user(&msg, buf, count)) return -EFAULT; - if (!msg.len || count < sizeof_field(struct ipmi_ssif_msg, len) + msg.len) + if (!msg.len || msg.len > IPMI_SSIF_PAYLOAD_MAX || + count < sizeof_field(struct ipmi_ssif_msg, len) + msg.len) return -EINVAL; spin_lock_irqsave(&ssif_bmc->lock, flags);