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authorJean-Baptiste Maneyrol <jmaneyrol@invensense.com>2014-11-20 00:46:37 +0800
committerJiri Kosina <jkosina@suse.cz>2014-11-25 15:24:54 +0100
commit6296f4a8eb86f9abcc370fb7a1a116b8441c17fd (patch)
treebea704c7efa5eda1c5ca33271b44e7a4d34df272
parent08bb7beae7fe102939fe5931222fc09e10d27cda (diff)
downloadlinux-6296f4a8eb86f9abcc370fb7a1a116b8441c17fd.tar.gz
HID: i2c-hid: fix race condition reading reports
Current driver uses a common buffer for reading reports either synchronously in i2c_hid_get_raw_report() and asynchronously in the interrupt handler. There is race condition if an interrupt arrives immediately after the report is received in i2c_hid_get_raw_report(); the common buffer is modified by the interrupt handler with the new report and then i2c_hid_get_raw_report() proceed using wrong data. Fix it by using a separate buffers for synchronous reports. Signed-off-by: Jean-Baptiste Maneyrol <jmaneyrol@invensense.com> [Antonio Borneo: cleanup, rebase to v3.17, submit mainline] Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com> Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Jiri Kosina <jkosina@suse.cz>
-rw-r--r--drivers/hid/i2c-hid/i2c-hid.c12
1 files changed, 8 insertions, 4 deletions
diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c
index 933bf1052ec0..c66e6acf7152 100644
--- a/drivers/hid/i2c-hid/i2c-hid.c
+++ b/drivers/hid/i2c-hid/i2c-hid.c
@@ -137,6 +137,7 @@ struct i2c_hid {
* descriptor. */
unsigned int bufsize; /* i2c buffer size */
char *inbuf; /* Input buffer */
+ char *rawbuf; /* Raw Input buffer */
char *cmdbuf; /* Command buffer */
char *argsbuf; /* Command arguments buffer */
@@ -504,9 +505,11 @@ static void i2c_hid_find_max_report(struct hid_device *hid, unsigned int type,
static void i2c_hid_free_buffers(struct i2c_hid *ihid)
{
kfree(ihid->inbuf);
+ kfree(ihid->rawbuf);
kfree(ihid->argsbuf);
kfree(ihid->cmdbuf);
ihid->inbuf = NULL;
+ ihid->rawbuf = NULL;
ihid->cmdbuf = NULL;
ihid->argsbuf = NULL;
ihid->bufsize = 0;
@@ -522,10 +525,11 @@ static int i2c_hid_alloc_buffers(struct i2c_hid *ihid, size_t report_size)
report_size; /* report */
ihid->inbuf = kzalloc(report_size, GFP_KERNEL);
+ ihid->rawbuf = kzalloc(report_size, GFP_KERNEL);
ihid->argsbuf = kzalloc(args_len, GFP_KERNEL);
ihid->cmdbuf = kzalloc(sizeof(union command) + args_len, GFP_KERNEL);
- if (!ihid->inbuf || !ihid->argsbuf || !ihid->cmdbuf) {
+ if (!ihid->inbuf || !ihid->rawbuf || !ihid->argsbuf || !ihid->cmdbuf) {
i2c_hid_free_buffers(ihid);
return -ENOMEM;
}
@@ -552,12 +556,12 @@ static int i2c_hid_get_raw_report(struct hid_device *hid,
ret = i2c_hid_get_report(client,
report_type == HID_FEATURE_REPORT ? 0x03 : 0x01,
- report_number, ihid->inbuf, ask_count);
+ report_number, ihid->rawbuf, ask_count);
if (ret < 0)
return ret;
- ret_count = ihid->inbuf[0] | (ihid->inbuf[1] << 8);
+ ret_count = ihid->rawbuf[0] | (ihid->rawbuf[1] << 8);
if (ret_count <= 2)
return 0;
@@ -566,7 +570,7 @@ static int i2c_hid_get_raw_report(struct hid_device *hid,
/* The query buffer contains the size, dropping it in the reply */
count = min(count, ret_count - 2);
- memcpy(buf, ihid->inbuf + 2, count);
+ memcpy(buf, ihid->rawbuf + 2, count);
return count;
}