3ab2011ea3
There is a race condition in tpm_common_write function allowing
two threads on the same /dev/tpm<N>, or two different applications
on the same /dev/tpmrm<N> to overwrite each other commands/responses.
Fixed this by taking the priv->buffer_mutex early in the function.
Also converted the priv->data_pending from atomic to a regular size_t
type. There is no need for it to be atomic since it is only touched
under the protection of the priv->buffer_mutex.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: stable@vger.kernel.org
Signed-off-by: Tadeusz Struk <tadeusz.struk@intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
29 lines
776 B
C
29 lines
776 B
C
/* SPDX-License-Identifier: GPL-2.0 */
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#ifndef _TPM_DEV_H
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#define _TPM_DEV_H
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#include "tpm.h"
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struct file_priv {
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struct tpm_chip *chip;
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/* Data passed to and from the tpm via the read/write calls */
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size_t data_pending;
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struct mutex buffer_mutex;
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struct timer_list user_read_timer; /* user needs to claim result */
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struct work_struct work;
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u8 data_buffer[TPM_BUFSIZE];
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};
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void tpm_common_open(struct file *file, struct tpm_chip *chip,
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struct file_priv *priv);
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ssize_t tpm_common_read(struct file *file, char __user *buf,
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size_t size, loff_t *off);
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ssize_t tpm_common_write(struct file *file, const char __user *buf,
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size_t size, loff_t *off, struct tpm_space *space);
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void tpm_common_release(struct file *file, struct file_priv *priv);
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#endif
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