FAILED: patch "[PATCH] i2c: smbus: kill memory leak on emulated and failed DMA SMBus" failed to apply to 4.17-stable tree

From 9aa613674f89d01248ae2e4afe691b515ff8fbb6 Mon Sep 17 00:00:00 2001

The patch below does not apply to the 4.17-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

Quoted 1 line

From 9aa613674f89d01248ae2e4afe691b515ff8fbb6 Mon Sep 17 00:00:00 2001

From: Peter Rosin <[email protected]>
Date: Wed, 20 Jun 2018 11:43:23 +0200
Subject: [PATCH] i2c: smbus: kill memory leak on emulated and failed DMA SMBus
xfers

If DMA safe memory was allocated, but the subsequent I2C transfer fails the memory is leaked. Plug this leak.

Fixes 8a77821e74d6 ("i2c: smbus: use DMA safe buffers for emulated

SMBus transactions")

Signed-off-by Peter Rosin <[email protected]>

Signed-off-by Wolfram Sang <[email protected]>

Cc [email protected]

drivers/i2c/i2c-core-smbus.c +7 -4

index f3f683041e7f..51970bae3c4a 100644
@@ -465,15 +465,18 @@ static s32 i2c_smbus_xfer_emulated(struct
 i2c_adapter *adapter, u16 addr,
 
 	status = i2c_transfer(adapter, msg, num);
 	if (status < 0)
-		return status;
-	if (status != num)
-		return -EIO;
+		goto cleanup;
+	if (status != num) {
+		status = -EIO;
+		goto cleanup;
+	}
+	status = 0;
 
 	/* Check PEC if last message is a read */
 	if (i && (msg[num-1].flags & I2C_M_RD)) {
 		status = i2c_smbus_check_pec(partial_pec, &msg[num-1]);
 		if (status < 0)
-			return status;
+			goto cleanup;
 	}
 

	if (read_write == I2C_SMBUS_READ)

drivers/i2c/i2c-core-smbus.c +2 -1

@@ -499,12 +502,13 @@ static s32 i2c_smbus_xfer_emulated(struct
 i2c_adapter *adapter, u16 addr,
 			break;
 		}
 
+cleanup:
 	if (msg[0].flags & I2C_M_DMA_SAFE)
 		kfree(msg[0].buf);
 	if (msg[1].flags & I2C_M_DMA_SAFE)
 		kfree(msg[1].buf);
 
-	return 0;
+	return status;
 }
 

/**

Quoted 5 lines · On July 1, 2018 3:51:18 PM GMT+02:00, [email protected] wrote:

The patch below does not apply to the 4.17-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

I think it might be enough to also backport 8e03477cb709 ("i2c: core: smbus: fix a potential missing-check bug")?

I have not tested if that is enough though (and am not in a position to easily do so)...