diff options
| author | Jean-Baptiste Maneyrol <jmaneyrol@invensense.com> | 2014-11-20 00:46:37 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-01-16 06:59:01 -0800 |
| commit | caa853b3d80473ec7a646a7e163ddf8bc1f4ef46 (patch) | |
| tree | d763df1652a8c91a1a16ffc7790bb3465dfa692f | |
| parent | b658f2ad07e5e15a8e29bb95740452bd5b6a8eea (diff) | |
HID: i2c-hid: fix race condition reading reports
commit 6296f4a8eb86f9abcc370fb7a1a116b8441c17fd upstream.
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>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/hid/i2c-hid/i2c-hid.c | 12 |
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 2b1799a3b212..25b9844f7e41 100644 --- a/drivers/hid/i2c-hid/i2c-hid.c +++ b/drivers/hid/i2c-hid/i2c-hid.c @@ -134,6 +134,7 @@ 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 */ @@ -471,9 +472,11 @@ 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; @@ -489,10 +492,11 @@ 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; } @@ -519,12 +523,12 @@ 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; @@ -533,7 +537,7 @@ 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; } |