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

Linus Torvalds committed 10 years ago

Commit 32cf95d2 parents 630aac5 d1306eb3 files · +27 −8Browse files

Unified · Split

3 files

drivers/hv/ring_buffer.c +20 −6
drivers/misc/mic/vop/vop_vringh.c +5 −0
drivers/nvmem/mxs-ocotp.c +2 −2

drivers/hv/ring_buffer.c+20−6

@@ -103,15 +103,29 @@ static bool hv_need_to_signal(u32 old_write, struct hv_ring_buffer_info *rbi) · 102 unmodified lines
103	103	* there is room for the producer to send the pending packet.
104	104	*/
105	105
106		−static bool hv_need_to_signal_on_read(u32 prev_write_sz,
107		− struct hv_ring_buffer_info *rbi)
	106	+static bool hv_need_to_signal_on_read(struct hv_ring_buffer_info *rbi)
108	107	{
109	108	u32 cur_write_sz;
110	109	u32 r_size;
111		− u32 write_loc = rbi->ring_buffer->write_index;
	110	+ u32 write_loc;
112	111	u32 read_loc = rbi->ring_buffer->read_index;
113		− u32 pending_sz = rbi->ring_buffer->pending_send_sz;
	112	+ u32 pending_sz;
114	113
	114	+ /*
	115	+ * Issue a full memory barrier before making the signaling decision.
	116	+ * Here is the reason for having this barrier:
	117	+ * If the reading of the pend_sz (in this function)
	118	+ * were to be reordered and read before we commit the new read
	119	+ * index (in the calling function) we could
	120	+ * have a problem. If the host were to set the pending_sz after we
	121	+ * have sampled pending_sz and go to sleep before we commit the
	122	+ * read index, we could miss sending the interrupt. Issue a full
	123	+ * memory barrier to address this.
	124	+ */
	125	+ mb();
	126	+
	127	+ pending_sz = rbi->ring_buffer->pending_send_sz;
	128	+ write_loc = rbi->ring_buffer->write_index;
115	129	/* If the other end is not blocked on write don't bother. */
116	130	if (pending_sz == 0)
117	131	return false;
@@ -120,7 +134,7 @@ static bool hv_need_to_signal_on_read(u32 prev_write_sz, · 2 unmodified lines
120	134	cur_write_sz = write_loc >= read_loc ? r_size - (write_loc - read_loc) :
121	135	read_loc - write_loc;
122	136
123		− if ((prev_write_sz < pending_sz) && (cur_write_sz >= pending_sz))
	137	+ if (cur_write_sz >= pending_sz)
124	138	return true;
125	139
126	140	return false;
@@ -455,7 +469,7 @@ int hv_ringbuffer_read(struct hv_ring_buffer_info *inring_info, · 328 unmodified lines
455	469	/* Update the read index */
456	470	hv_set_next_read_location(inring_info, next_read_location);
457	471
458		− *signal = hv_need_to_signal_on_read(bytes_avail_towrite, inring_info);
	472	+ *signal = hv_need_to_signal_on_read(inring_info);
459	473
460	474	return ret;
461	475	}

drivers/misc/mic/vop/vop_vringh.c+5−0

@@ -945,6 +945,11 @@ static long vop_ioctl(struct file *f, unsigned int cmd, unsigned long arg) · 944 unmodified lines
945	945	ret = -EFAULT;
946	946	goto free_ret;
947	947	}
	948	+ /* Ensure desc has not changed between the two reads */
	949	+ if (memcmp(&dd, dd_config, sizeof(dd))) {
	950	+ ret = -EINVAL;
	951	+ goto free_ret;
	952	+ }
948	953	mutex_lock(&vdev->vdev_mutex);
949	954	mutex_lock(&vi->vop_mutex);
950	955	ret = vop_virtio_add_device(vdev, dd_config);

drivers/nvmem/mxs-ocotp.c+2−2

@@ -94,7 +94,7 @@ static int mxs_ocotp_read(void context, const void reg, size_t reg_size, · 93 unmodified lines
94	94	if (ret)
95	95	goto close_banks;
96	96
97		− while (val_size) {
	97	+ while (val_size >= reg_size) {
98	98	if ((offset < OCOTP_DATA_OFFSET) \|\| (offset % 16)) {
99	99	/* fill up non-data register */
100	100	*buf = 0;
@@ -103,7 +103,7 @@ static int mxs_ocotp_read(void context, const void reg, size_t reg_size, · 2 unmodified lines
103	103	}
104	104
105	105	buf++;
106		− val_size--;
	106	+ val_size -= reg_size;
107	107	offset += reg_size;
108	108	}
109	109