Home Home > GIT Browse
summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2016-05-07 10:53:32 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-05-07 10:53:32 -0700
commit32cf95db22d49cf4a3b421ba9fd156bb5f920ebb (patch)
tree48df4fe0b994c33155c7b19269621f6c122fee60
parent630aac5ab6d6708c2cf715ddb5a77928e0aacb04 (diff)
parentd1306eb675ad7a9a760b6b8e8e189824b8db89e7 (diff)
Merge tag 'char-misc-4.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull misc driver fixes from Gfreg KH: "Here are three small fixes for some driver problems that were reported. Full details in the shortlog below. All of these have been in linux-next with no reported issues" * tag 'char-misc-4.6-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: nvmem: mxs-ocotp: fix buffer overflow in read Drivers: hv: vmbus: Fix signaling logic in hv_need_to_signal_on_read() misc: mic: Fix for double fetch security bug in VOP driver
-rw-r--r--drivers/hv/ring_buffer.c26
-rw-r--r--drivers/misc/mic/vop/vop_vringh.c5
-rw-r--r--drivers/nvmem/mxs-ocotp.c4
3 files changed, 27 insertions, 8 deletions
diff --git a/drivers/hv/ring_buffer.c b/drivers/hv/ring_buffer.c
index 5613e2b5cff7..a40a73a7b71d 100644
--- a/drivers/hv/ring_buffer.c
+++ b/drivers/hv/ring_buffer.c
@@ -103,15 +103,29 @@ static bool hv_need_to_signal(u32 old_write, struct hv_ring_buffer_info *rbi)
* there is room for the producer to send the pending packet.
*/
-static bool hv_need_to_signal_on_read(u32 prev_write_sz,
- struct hv_ring_buffer_info *rbi)
+static bool hv_need_to_signal_on_read(struct hv_ring_buffer_info *rbi)
{
u32 cur_write_sz;
u32 r_size;
- u32 write_loc = rbi->ring_buffer->write_index;
+ u32 write_loc;
u32 read_loc = rbi->ring_buffer->read_index;
- u32 pending_sz = rbi->ring_buffer->pending_send_sz;
+ u32 pending_sz;
+ /*
+ * Issue a full memory barrier before making the signaling decision.
+ * Here is the reason for having this barrier:
+ * If the reading of the pend_sz (in this function)
+ * were to be reordered and read before we commit the new read
+ * index (in the calling function) we could
+ * have a problem. If the host were to set the pending_sz after we
+ * have sampled pending_sz and go to sleep before we commit the
+ * read index, we could miss sending the interrupt. Issue a full
+ * memory barrier to address this.
+ */
+ mb();
+
+ pending_sz = rbi->ring_buffer->pending_send_sz;
+ write_loc = rbi->ring_buffer->write_index;
/* If the other end is not blocked on write don't bother. */
if (pending_sz == 0)
return false;
@@ -120,7 +134,7 @@ static bool hv_need_to_signal_on_read(u32 prev_write_sz,
cur_write_sz = write_loc >= read_loc ? r_size - (write_loc - read_loc) :
read_loc - write_loc;
- if ((prev_write_sz < pending_sz) && (cur_write_sz >= pending_sz))
+ if (cur_write_sz >= pending_sz)
return true;
return false;
@@ -455,7 +469,7 @@ int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info,
/* Update the read index */
hv_set_next_read_location(inring_info, next_read_location);
- *signal = hv_need_to_signal_on_read(bytes_avail_towrite, inring_info);
+ *signal = hv_need_to_signal_on_read(inring_info);
return ret;
}
diff --git a/drivers/misc/mic/vop/vop_vringh.c b/drivers/misc/mic/vop/vop_vringh.c
index e94c7fb6712a..88e45234d527 100644
--- a/drivers/misc/mic/vop/vop_vringh.c
+++ b/drivers/misc/mic/vop/vop_vringh.c
@@ -945,6 +945,11 @@ static long vop_ioctl(struct file *f, unsigned int cmd, unsigned long arg)
ret = -EFAULT;
goto free_ret;
}
+ /* Ensure desc has not changed between the two reads */
+ if (memcmp(&dd, dd_config, sizeof(dd))) {
+ ret = -EINVAL;
+ goto free_ret;
+ }
mutex_lock(&vdev->vdev_mutex);
mutex_lock(&vi->vop_mutex);
ret = vop_virtio_add_device(vdev, dd_config);
diff --git a/drivers/nvmem/mxs-ocotp.c b/drivers/nvmem/mxs-ocotp.c
index 8ba19bba3156..2bb3c5799ac4 100644
--- a/drivers/nvmem/mxs-ocotp.c
+++ b/drivers/nvmem/mxs-ocotp.c
@@ -94,7 +94,7 @@ static int mxs_ocotp_read(void *context, const void *reg, size_t reg_size,
if (ret)
goto close_banks;
- while (val_size) {
+ while (val_size >= reg_size) {
if ((offset < OCOTP_DATA_OFFSET) || (offset % 16)) {
/* fill up non-data register */
*buf = 0;
@@ -103,7 +103,7 @@ static int mxs_ocotp_read(void *context, const void *reg, size_t reg_size,
}
buf++;
- val_size--;
+ val_size -= reg_size;
offset += reg_size;
}