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

    regmap: fix kernel hang on regmap_bulk_write with zero val_count.

to the 3.14-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-fix-kernel-hang-on-regmap_bulk_write-with-zero-val_count.patch
and it can be found in the queue-3.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.


>From 48a47140d74e7116a14f5300ebcff220176f48ac Mon Sep 17 00:00:00 2001
From: Quentin Casasnovas <[email protected]>
Date: Wed, 12 Nov 2014 11:19:23 +0100
Subject: regmap: fix kernel hang on regmap_bulk_write with zero val_count.

From: Quentin Casasnovas <[email protected]>

Fixes commit 2f06fa04cf35da5c24481da3ac84a2900d0b99c3 which was an
incorrect backported version of commit
d6b41cb06044a7d895db82bdd54f6e4219970510 upstream.

If val_count is zero we return -EINVAL with map->lock_arg locked, which
will deadlock the kernel next time we try to acquire this lock.

This was introduced by f5942dd ("regmap: fix possible ZERO_SIZE_PTR pointer
dereferencing error.") which improperly back-ported d6b41cb0.

This issue was found during review of Ubuntu Trusty 3.13.0-40.68 kernel to
prepare Ksplice rebootless updates.

Fixes: f5942dd ("regmap: fix possible ZERO_SIZE_PTR pointer dereferencing 
error.")
Signed-off-by: Quentin Casasnovas <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
 drivers/base/regmap/regmap.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -1557,8 +1557,10 @@ int regmap_bulk_write(struct regmap *map
        } else {
                void *wval;
 
-               if (!val_count)
-                       return -EINVAL;
+               if (!val_count) {
+                       ret = -EINVAL;
+                       goto out;
+               }
 
                wval = kmemdup(val, val_count * val_bytes, GFP_KERNEL);
                if (!wval) {


Patches currently in stable-queue which might be from 
[email protected] are

queue-3.14/regmap-fix-kernel-hang-on-regmap_bulk_write-with-zero-val_count.patch
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