Input: hideep - fix the uninitialized use in hideep_nvm_unlock()

stable inclusion
from linux-4.19.198
commit c71a120d34dcda696664c1ee74868f217d4fc4b6

--------------------------------

[ Upstream commit cac7100d ]

Inside function hideep_nvm_unlock(), variable "unmask_code" could
be uninitialized if hideep_pgm_r_reg() returns error, however, it
is used in the later if statement after an "and" operation, which
is potentially unsafe.
Signed-off-by: NYizhuo <yzhai003@ucr.edu>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

drivers/input/touchscreen/hideep.c

@@ -364,13 +364,16 @@ static int hideep_enter_pgm(struct hideep_ts *ts)
 	return -EIO;
 }
 
-static void hideep_nvm_unlock(struct hideep_ts *ts)
+static int hideep_nvm_unlock(struct hideep_ts *ts)
 {
 	u32 unmask_code;
+	int error;
 
 	hideep_pgm_w_reg(ts, HIDEEP_FLASH_CFG, HIDEEP_NVM_SFR_RPAGE);
-	hideep_pgm_r_reg(ts, 0x0000000C, &unmask_code);
+	error = hideep_pgm_r_reg(ts, 0x0000000C, &unmask_code);
 	hideep_pgm_w_reg(ts, HIDEEP_FLASH_CFG, HIDEEP_NVM_DEFAULT_PAGE);
+	if (error)
+		return error;
 
 	/* make it unprotected code */
 	unmask_code &= ~HIDEEP_PROT_MODE;
@@ -387,6 +390,8 @@ static void hideep_nvm_unlock(struct hideep_ts *ts)
 	NVM_W_SFR(HIDEEP_NVM_MASK_OFS, ts->nvm_mask);
 	SET_FLASH_HWCONTROL();
 	hideep_pgm_w_reg(ts, HIDEEP_FLASH_CFG, HIDEEP_NVM_DEFAULT_PAGE);
+
+	return 0;
 }
 
 static int hideep_check_status(struct hideep_ts *ts)
@@ -465,7 +470,9 @@ static int hideep_program_nvm(struct hideep_ts *ts,
 	u32 addr = 0;
 	int error;
 
-	hideep_nvm_unlock(ts);
+       error = hideep_nvm_unlock(ts);
+       if (error)
+               return error;
 
 	while (ucode_len > 0) {
 		xfer_len = min_t(size_t, ucode_len, HIDEEP_NVM_PAGE_SIZE);