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 <stable@xxxxxxxxxxxxxxx> know about it.
>From 48a47140d74e7116a14f5300ebcff220176f48ac Mon Sep 17 00:00:00 2001
From: Quentin Casasnovas <quentin.casasnovas@xxxxxxxxxx>
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 <quentin.casasnovas@xxxxxxxxxx>
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 <quentin.casasnovas@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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 quentin.casasnovas@xxxxxxxxxx are
queue-3.14/regmap-fix-kernel-hang-on-regmap_bulk_write-with-zero-val_count.patch
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