Patch "regmap: debugfs: Ensure we don't underflow when printing access masks" has been added to the 4.2-stable tree

Patch "regmap: debugfs: Ensure we don't underflow when printing access masks" has been added to the 4.2-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    regmap: debugfs: Ensure we don't underflow when printing access masks

to the 4.2-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     regmap-debugfs-ensure-we-don-t-underflow-when-printing-access-masks.patch
and it can be found in the queue-4.2 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From b763ec17ac762470eec5be8ebcc43e4f8b2c2b82 Mon Sep 17 00:00:00 2001
From: Mark Brown <broonie@kernel.org>
Date: Sat, 19 Sep 2015 07:00:18 -0700
Subject: regmap: debugfs: Ensure we don't underflow when printing access masks

From: Mark Brown <broonie@kernel.org>

commit b763ec17ac762470eec5be8ebcc43e4f8b2c2b82 upstream.

If a read is attempted which is smaller than the line length then we may
underflow the subtraction we're doing with the unsigned size_t type so
move some of the calculation to be additions on the right hand side
instead in order to avoid this.

Reported-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/base/regmap/regmap-debugfs.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/base/regmap/regmap-debugfs.c
+++ b/drivers/base/regmap/regmap-debugfs.c
@@ -432,7 +432,7 @@ static ssize_t regmap_access_read_file(s
 		/* If we're in the region the user is trying to read */
 		if (p >= *ppos) {
 			/* ...but not beyond it */
-			if (buf_pos >= count - 1 - tot_len)
+			if (buf_pos + tot_len + 1 >= count)
 				break;
 
 			/* Format the register */


Patches currently in stable-queue which might be from broonie@kernel.org are

queue-4.2/asoc-pxa-pxa2xx-ac97-fix-dma-requestor-lines.patch
queue-4.2/spi-xtensa-xtfpga-fix-register-endianness.patch
queue-4.2/spi-bcm2835-bug-fix-wrong-use-of-page_mask.patch
queue-4.2/regmap-debugfs-ensure-we-don-t-underflow-when-printing-access-masks.patch
queue-4.2/spi-fix-documentation-of-spi_alloc_master.patch
queue-4.2/regulator-core-correct-return-value-check-in-regulator_resolve_supply.patch
queue-4.2/asoc-fix-broken-pxa-soc-support.patch
queue-4.2/asoc-sgtl5000-fix-wrong-register-mic_bias_voltage-setup-on-probe.patch
queue-4.2/asoc-dwc-correct-irq-clear-method.patch
queue-4.2/asoc-db1200-fix-dai-link-format-for-db1300-and-db1550.patch
queue-4.2/regulator-axp20x-fix-enable-bit-indexes-for-dcdc4-and-dcdc5.patch
queue-4.2/regulator-core-handle-probe-deferral-from-dt-when-resolving-supplies.patch
queue-4.2/spi-spidev-fix-possible-null-dereference.patch
queue-4.2/asoc-tas2552-fix-dbscale-min-declaration.patch
queue-4.2/regmap-debugfs-don-t-bother-actually-printing-when-calculating-max-length.patch
queue-4.2/spi-spi-pxa2xx-check-status-register-to-determine-if-sssr_tint-is-disabled.patch