Messages in this thread | | | Date | Sun, 11 Sep 2016 22:05:46 -0600 | From | Jason Gunthorpe <> | Subject | Re: [PATCH] tpm: fix buffer overflow in /dev/tpm0 |
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On Sun, Sep 11, 2016 at 03:19:00PM +0300, Jarkko Sakkinen wrote: > tpm_write() does not check whether the buffer has at least enough space > for the header before passing it to tpm_transmit() so an overflow can > happen.
Eh?
tpm_write uses a hard wired buffer size of TPM_BUFSIZE when working with tpm_transmit.
in_size is never used except for the copy. We should probably fix that to sanity check the header length vs in_size.
That doesn't seem to be a security issue however because the header length is propery limited to TPM_BUFSIZE and the data buffer is allocated specifically for that process using kzalloc.
Jason
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