Return-Path: From: lizf@kernel.org To: stable@vger.kernel.org Cc: linux-kernel@vger.kernel.org, Xiubo Li , Mark Brown , Zefan Li Subject: [PATCH 3.4 032/177] regmap: fix possible ZERO_SIZE_PTR pointer dereferencing error. Date: Wed, 28 Jan 2015 12:07:11 +0800 Message-Id: <1422418236-12852-64-git-send-email-lizf@kernel.org> In-Reply-To: <1422418050-12581-1-git-send-email-lizf@kernel.org> References: <1422418050-12581-1-git-send-email-lizf@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: From: Xiubo Li 3.4.106-rc1 review patch. If anyone has any objections, please let me know. ------------------ commit d6b41cb06044a7d895db82bdd54f6e4219970510 upstream. Since we cannot make sure the 'val_count' will always be none zero here, and then if it equals to zero, the kmemdup() will return ZERO_SIZE_PTR, which equals to ((void *)16). So this patch fix this with just doing the zero check before calling kmemdup(). Signed-off-by: Xiubo Li Signed-off-by: Mark Brown [lizf: Backported to 3.4: release mutex before returning EINVAL] Signed-off-by: Zefan Li --- drivers/base/regmap/regmap.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index e554542..8e81f85 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -600,6 +600,11 @@ int regmap_bulk_write(struct regmap *map, unsigned int reg, const void *val, if (val_bytes == 1) { wval = (void *)val; } else { + if (!val_count) { + ret = -EINVAL; + goto out; + } + wval = kmemdup(val, val_count * val_bytes, GFP_KERNEL); if (!wval) { ret = -ENOMEM; -- 1.9.1