ipmi: ssif_bmc: prevent integer overflow on 32bit systems
BugLink: https://bugs.launchpad.net/bugs/2083196
[ 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: dd2bc5cc9e ("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>
Signed-off-by: Portia Stephens <portia.stephens@canonical.com>
Signed-off-by: Roxana Nicolescu <roxana.nicolescu@canonical.com>
This commit is contained in:
committed by
Mehmet Basaran
parent
3787a7506b
commit
ee69d507ce
@@ -177,13 +177,15 @@ static ssize_t ssif_bmc_write(struct file *file, const char __user *buf, size_t
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unsigned long flags;
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ssize_t ret;
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if (count > sizeof(struct ipmi_ssif_msg))
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if (count < sizeof(msg.len) ||
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count > sizeof(struct ipmi_ssif_msg))
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return -EINVAL;
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if (copy_from_user(&msg, buf, count))
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return -EFAULT;
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if (!msg.len || count < sizeof_field(struct ipmi_ssif_msg, len) + msg.len)
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if (!msg.len || msg.len > IPMI_SSIF_PAYLOAD_MAX ||
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count < sizeof_field(struct ipmi_ssif_msg, len) + msg.len)
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return -EINVAL;
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spin_lock_irqsave(&ssif_bmc->lock, flags);
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