From: Xiubo Li Date: Wed, 30 Apr 2014 09:31:08 +0000 (+0800) Subject: regmap: Fix possible ZERO_SIZE_PTR pointer dereferencing error. X-Git-Tag: firefly_0821_release~176^2~3465^2~33^2~2^2~2 X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=f5727cd31283aa478f7f9396c6eb7b5aceebb869;p=firefly-linux-kernel-4.4.55.git regmap: Fix possible ZERO_SIZE_PTR pointer dereferencing error. Since we cannot make sure the 'len = pair_size * num_regs' will always be none zero from the users, and then if 'num_regs' equals to zero by mistake or other reasons, the kzalloc() will return ZERO_SIZE_PTR, which equals to ((void *)16). So this patch fix this with just doing the 'len' zero check before calling kzalloc(). Signed-off-by: Xiubo Li Signed-off-by: Mark Brown --- diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 63e30ef096e2..9596f3048939 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -1615,6 +1615,9 @@ static int _regmap_raw_multi_reg_write(struct regmap *map, size_t pair_size = reg_bytes + pad_bytes + val_bytes; size_t len = pair_size * num_regs; + if (!len) + return -EINVAL; + buf = kzalloc(len, GFP_KERNEL); if (!buf) return -ENOMEM;