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[PATCH 1/2] mmc: core: guard dereference of optional parameter

From "Tobin C. Harding" <me@tobin.cc>
Newsgroups linux.kernel
Subject [PATCH 1/2] mmc: core: guard dereference of optional parameter
Date 2017-03-15 09:50 +0100
Message-ID <tlcN3-573-13@gated-at.bofh.it> (permalink)
References <tlcN3-573-1@gated-at.bofh.it>
Organization linux.* mail to news gateway

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Various functions take as parameter an optional pointer. Pointer
should be guarded with non-NULL check before dereferencing.

Add non-NULL check before dereference of pointer.

Signed-off-by: Tobin C. Harding <me@tobin.cc>
---
 drivers/mmc/core/sdio_io.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/mmc/core/sdio_io.c b/drivers/mmc/core/sdio_io.c
index 74195d7..3482314 100644
--- a/drivers/mmc/core/sdio_io.c
+++ b/drivers/mmc/core/sdio_io.c
@@ -373,7 +373,8 @@ u8 sdio_readb(struct sdio_func *func, unsigned int addr, int *err_ret)
 	u8 val;
 
 	if (!func) {
-		*err_ret = -EINVAL;
+		if (err_ret)
+			*err_ret = -EINVAL;
 		return 0xFF;
 	}
 
@@ -407,7 +408,8 @@ void sdio_writeb(struct sdio_func *func, u8 b, unsigned int addr, int *err_ret)
 	int ret;
 
 	if (!func) {
-		*err_ret = -EINVAL;
+		if (err_ret)
+			*err_ret = -EINVAL;
 		return;
 	}
 
@@ -635,7 +637,8 @@ unsigned char sdio_f0_readb(struct sdio_func *func, unsigned int addr,
 	unsigned char val;
 
 	if (!func) {
-		*err_ret = -EINVAL;
+		if (err_ret)
+			*err_ret = -EINVAL;
 		return 0xFF;
 	}
 
@@ -673,7 +676,8 @@ void sdio_f0_writeb(struct sdio_func *func, unsigned char b, unsigned int addr,
 	int ret;
 
 	if (!func) {
-		*err_ret = -EINVAL;
+		if (err_ret)
+			*err_ret = -EINVAL;
 		return;
 	}
 
-- 
2.7.4

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Thread

[PATCH 0/2] mmc: core: null pointer dereference bug "Tobin C. Harding" <me@tobin.cc> - 2017-03-15 09:50 +0100
  [PATCH 2/2] mmc: core: simplify return code "Tobin C. Harding" <me@tobin.cc> - 2017-03-15 09:50 +0100
  [PATCH 1/2] mmc: core: guard dereference of optional parameter "Tobin C. Harding" <me@tobin.cc> - 2017-03-15 09:50 +0100
  Re: [PATCH 0/2] mmc: core: null pointer dereference bug Ulf Hansson <ulf.hansson@linaro.org> - 2017-03-16 15:50 +0100

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