rtlwifi: fix null dereference on efuse_word on kmalloc fail returns NULL

Commit Message

Colin King Oct. 28, 2013, 12:58 p.m. UTC

From: Colin Ian King <[e-mail]>

kmalloc on efuse_word can return null, leading to free'ing of
elements in efuse_word on the error exit path even though it has not
been allocated.  Instead, don't free the elements of efuse_word if
kmalloc failed.

Also, kmalloc of any of the arrays in efuse_word[] can also fail,
leading to undefined contents in the remaining elements leading to
problems when free'ing these elements later on.  So kzalloc efuse_word
to ensure the kfree on the remaining elements won't cause breakage.

Signed-off-by: Colin Ian King <[e-mail]>
---
 drivers/net/wireless/rtlwifi/efuse.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

Patch

diff --git a/drivers/net/wireless/rtlwifi/efuse.c b/drivers/net/wireless/rtlwifi/efuse.c
index 838a1ed..66f0b2d 100644
--- a/drivers/net/wireless/rtlwifi/efuse.c
+++ b/drivers/net/wireless/rtlwifi/efuse.c
@@ -262,9 +262,9 @@  void read_efuse(struct ieee80211_hw *hw, u16 _offset, u16 _size_byte, u8 *pbuf)
 			    sizeof(u8), GFP_ATOMIC);
 	if (!efuse_tbl)
 		return;
-	efuse_word = kmalloc(EFUSE_MAX_WORD_UNIT * sizeof(u16 *), GFP_ATOMIC);
+	efuse_word = kzalloc(EFUSE_MAX_WORD_UNIT * sizeof(u16 *), GFP_ATOMIC);
 	if (!efuse_word)
-		goto done;
+		goto out;
 	for (i = 0; i < EFUSE_MAX_WORD_UNIT; i++) {
 		efuse_word[i] = kmalloc(efuse_max_section * sizeof(u16),
 					GFP_ATOMIC);
@@ -378,6 +378,7 @@  done:
 	for (i = 0; i < EFUSE_MAX_WORD_UNIT; i++)
 		kfree(efuse_word[i]);
 	kfree(efuse_word);
+out:
 	kfree(efuse_tbl);
 }