* [PATCH 1/3] TPM: Zero buffer whole after copying to userspace [not found] <1323196162-2717-1-git-send-email-tim.gardner@canonical.com> @ 2011-12-06 18:29 ` Tim Gardner 2012-02-03 17:39 ` Rajiv Andrade 2011-12-06 18:29 ` [PATCH 2/3] TPM: Close data_pending and data_buffer races Tim Gardner 1 sibling, 1 reply; 4+ messages in thread From: Tim Gardner @ 2011-12-06 18:29 UTC (permalink / raw) To: linux-kernel Cc: Seth Forshee, Tim Gardner, Debora Velarde, Rajiv Andrade, Marcel Selhorst, tpmdd-devel, stable Commit 3321c07ae5068568cd61ac9f4ba749006a7185c9 correctly clears the TPM buffer if the user specified read length is >= the TPM buffer length. However, if the user specified read length is < the TPM buffer length, then part of the TPM buffer is left uncleared. Reported-by: Seth Forshee <seth.forshee@canonical.com> Cc: Debora Velarde <debora@linux.vnet.ibm.com> Cc: Rajiv Andrade <srajiv@linux.vnet.ibm.com> Cc: Marcel Selhorst <m.selhorst@sirrix.com> Cc: tpmdd-devel@lists.sourceforge.net Cc: stable@vger.kernel.org Signed-off-by: Tim Gardner <tim.gardner@canonical.com> --- drivers/char/tpm/tpm.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c index 361a1df..b366b34 100644 --- a/drivers/char/tpm/tpm.c +++ b/drivers/char/tpm/tpm.c @@ -1115,12 +1115,13 @@ ssize_t tpm_read(struct file *file, char __user *buf, ret_size = atomic_read(&chip->data_pending); atomic_set(&chip->data_pending, 0); if (ret_size > 0) { /* relay data */ + ssize_t orig_ret_size = ret_size; if (size < ret_size) ret_size = size; mutex_lock(&chip->buffer_mutex); rc = copy_to_user(buf, chip->data_buffer, ret_size); - memset(chip->data_buffer, 0, ret_size); + memset(chip->data_buffer, 0, orig_ret_size); if (rc) ret_size = -EFAULT; -- 1.7.0.4 ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH 1/3] TPM: Zero buffer whole after copying to userspace 2011-12-06 18:29 ` [PATCH 1/3] TPM: Zero buffer whole after copying to userspace Tim Gardner @ 2012-02-03 17:39 ` Rajiv Andrade 0 siblings, 0 replies; 4+ messages in thread From: Rajiv Andrade @ 2012-02-03 17:39 UTC (permalink / raw) To: Tim Gardner Cc: linux-kernel, Seth Forshee, Debora Velarde, Marcel Selhorst, tpmdd-devel, stable On Tue, 06 Dec 2011, Tim Gardner wrote: > Commit 3321c07ae5068568cd61ac9f4ba749006a7185c9 correctly clears the TPM > buffer if the user specified read length is >= the TPM buffer length. However, > if the user specified read length is < the TPM buffer length, then part of the > TPM buffer is left uncleared. > > Reported-by: Seth Forshee <seth.forshee@canonical.com> > Cc: Debora Velarde <debora@linux.vnet.ibm.com> > Cc: Rajiv Andrade <srajiv@linux.vnet.ibm.com> > Cc: Marcel Selhorst <m.selhorst@sirrix.com> > Cc: tpmdd-devel@lists.sourceforge.net > Cc: stable@vger.kernel.org > Signed-off-by: Tim Gardner <tim.gardner@canonical.com> Applied to github.com:srajiv/tpm.git next Thanks, Rajiv ^ permalink raw reply [flat|nested] 4+ messages in thread
* [PATCH 2/3] TPM: Close data_pending and data_buffer races [not found] <1323196162-2717-1-git-send-email-tim.gardner@canonical.com> 2011-12-06 18:29 ` [PATCH 1/3] TPM: Zero buffer whole after copying to userspace Tim Gardner @ 2011-12-06 18:29 ` Tim Gardner 2011-12-20 16:38 ` Rajiv Andrade 1 sibling, 1 reply; 4+ messages in thread From: Tim Gardner @ 2011-12-06 18:29 UTC (permalink / raw) To: linux-kernel Cc: Seth Forshee, Tim Gardner, Debora Velarde, Rajiv Andrade, Marcel Selhorst, tpmdd-devel, stable There is a race betwen tpm_read() and tpm_write where both chip->data_pending and chip->data_buffer can be changed by tpm_write() when tpm_read() clears chip->data_pending, but before tpm_read() grabs the mutex. Protect changes to chip->data_pending and chip->data_buffer by expanding the scope of chip->buffer_mutex. Reported-by: Seth Forshee <seth.forshee@canonical.com> Cc: Debora Velarde <debora@linux.vnet.ibm.com> Cc: Rajiv Andrade <srajiv@linux.vnet.ibm.com> Cc: Marcel Selhorst <m.selhorst@sirrix.com> Cc: tpmdd-devel@lists.sourceforge.net Cc: stable@vger.kernel.org Signed-off-by: Tim Gardner <tim.gardner@canonical.com> --- drivers/char/tpm/tpm.c | 17 +++++++++-------- 1 files changed, 9 insertions(+), 8 deletions(-) diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c index b366b34..70bf9e5 100644 --- a/drivers/char/tpm/tpm.c +++ b/drivers/char/tpm/tpm.c @@ -1074,12 +1074,15 @@ ssize_t tpm_write(struct file *file, const char __user *buf, struct tpm_chip *chip = file->private_data; size_t in_size = size, out_size; + mutex_lock(&chip->buffer_mutex); + /* cannot perform a write until the read has cleared either via tpm_read or a user_read_timer timeout */ - while (atomic_read(&chip->data_pending) != 0) + while (atomic_read(&chip->data_pending) != 0) { + mutex_unlock(&chip->buffer_mutex); msleep(TPM_TIMEOUT); - - mutex_lock(&chip->buffer_mutex); + mutex_lock(&chip->buffer_mutex); + } if (in_size > TPM_BUFSIZE) in_size = TPM_BUFSIZE; @@ -1112,22 +1115,20 @@ ssize_t tpm_read(struct file *file, char __user *buf, del_singleshot_timer_sync(&chip->user_read_timer); flush_work_sync(&chip->work); - ret_size = atomic_read(&chip->data_pending); - atomic_set(&chip->data_pending, 0); + mutex_lock(&chip->buffer_mutex); + ret_size = atomic_xchg(&chip->data_pending, 0); if (ret_size > 0) { /* relay data */ ssize_t orig_ret_size = ret_size; if (size < ret_size) ret_size = size; - mutex_lock(&chip->buffer_mutex); rc = copy_to_user(buf, chip->data_buffer, ret_size); memset(chip->data_buffer, 0, orig_ret_size); if (rc) ret_size = -EFAULT; - - mutex_unlock(&chip->buffer_mutex); } + mutex_unlock(&chip->buffer_mutex); return ret_size; } EXPORT_SYMBOL_GPL(tpm_read); -- 1.7.0.4 ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH 2/3] TPM: Close data_pending and data_buffer races 2011-12-06 18:29 ` [PATCH 2/3] TPM: Close data_pending and data_buffer races Tim Gardner @ 2011-12-20 16:38 ` Rajiv Andrade 0 siblings, 0 replies; 4+ messages in thread From: Rajiv Andrade @ 2011-12-20 16:38 UTC (permalink / raw) To: Tim Gardner Cc: linux-kernel, Seth Forshee, Debora Velarde, Marcel Selhorst, tpmdd-devel, stable On 06/12/11 16:29, Tim Gardner wrote: > There is a race betwen tpm_read() and tpm_write where both chip->data_pending > and chip->data_buffer can be changed by tpm_write() when tpm_read() > clears chip->data_pending, but before tpm_read() grabs the mutex. > > Protect changes to chip->data_pending and chip->data_buffer by expanding > the scope of chip->buffer_mutex. > > Reported-by: Seth Forshee<seth.forshee@canonical.com> > Cc: Debora Velarde<debora@linux.vnet.ibm.com> > Cc: Rajiv Andrade<srajiv@linux.vnet.ibm.com> > Cc: Marcel Selhorst<m.selhorst@sirrix.com> > Cc: tpmdd-devel@lists.sourceforge.net > Cc: stable@vger.kernel.org > Signed-off-by: Tim Gardner<tim.gardner@canonical.com> > --- > drivers/char/tpm/tpm.c | 17 +++++++++-------- > 1 files changed, 9 insertions(+), 8 deletions(-) > > diff --git a/drivers/char/tpm/tpm.c b/drivers/char/tpm/tpm.c > index b366b34..70bf9e5 100644 > --- a/drivers/char/tpm/tpm.c > +++ b/drivers/char/tpm/tpm.c > @@ -1074,12 +1074,15 @@ ssize_t tpm_write(struct file *file, const char __user *buf, > struct tpm_chip *chip = file->private_data; > size_t in_size = size, out_size; > > + mutex_lock(&chip->buffer_mutex); > + > /* cannot perform a write until the read has cleared > either via tpm_read or a user_read_timer timeout */ > - while (atomic_read(&chip->data_pending) != 0) > + while (atomic_read(&chip->data_pending) != 0) { > + mutex_unlock(&chip->buffer_mutex); > msleep(TPM_TIMEOUT); > - > - mutex_lock(&chip->buffer_mutex); > + mutex_lock(&chip->buffer_mutex); > + } > > if (in_size> TPM_BUFSIZE) > in_size = TPM_BUFSIZE; > @@ -1112,22 +1115,20 @@ ssize_t tpm_read(struct file *file, char __user *buf, > > del_singleshot_timer_sync(&chip->user_read_timer); > flush_work_sync(&chip->work); > - ret_size = atomic_read(&chip->data_pending); > - atomic_set(&chip->data_pending, 0); > + mutex_lock(&chip->buffer_mutex); > + ret_size = atomic_xchg(&chip->data_pending, 0); > if (ret_size> 0) { /* relay data */ > ssize_t orig_ret_size = ret_size; > if (size< ret_size) > ret_size = size; > > - mutex_lock(&chip->buffer_mutex); > rc = copy_to_user(buf, chip->data_buffer, ret_size); > memset(chip->data_buffer, 0, orig_ret_size); > if (rc) > ret_size = -EFAULT; What about just moving atomic_set(&chip->data_pending, 0); to here? If I'm not missing anything, this would be cleaner. Rajiv > - > - mutex_unlock(&chip->buffer_mutex); > } > > + mutex_unlock(&chip->buffer_mutex); > return ret_size; > } > EXPORT_SYMBOL_GPL(tpm_read); ^ permalink raw reply [flat|nested] 4+ messages in thread
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2011-12-06 18:29 ` [PATCH 1/3] TPM: Zero buffer whole after copying to userspace Tim Gardner
2012-02-03 17:39 ` Rajiv Andrade
2011-12-06 18:29 ` [PATCH 2/3] TPM: Close data_pending and data_buffer races Tim Gardner
2011-12-20 16:38 ` Rajiv Andrade
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