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| author | Dan Carpenter <dan.carpenter@linaro.org> | 2024-06-14 20:30:44 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-08-03 08:59:55 +0200 |
| commit | 898d200148d03cbaec0c63cd670445a2bb4a51a3 (patch) | |
| tree | 22a4eeec6fe323b07235c6de1b7d096779681acf | |
| parent | 5f8c27d3985edc7bdab84ca180dbc4f0edd4628f (diff) | |
| download | linux-stable-898d200148d03cbaec0c63cd670445a2bb4a51a3.tar.gz linux-stable-898d200148d03cbaec0c63cd670445a2bb4a51a3.tar.bz2 linux-stable-898d200148d03cbaec0c63cd670445a2bb4a51a3.zip | |
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@linaro.org>
Message-Id: <1431ca2e-4e9c-4520-bfc0-6879313c30e9@moroto.mountain>
Signed-off-by: Corey Minyard <corey@minyard.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/char/ipmi/ssif_bmc.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/char/ipmi/ssif_bmc.c b/drivers/char/ipmi/ssif_bmc.c index 56346fb32872..ab4e87a99f08 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); |