[PATCH AUTOSEL 4.9 05/15] rtc: pcf2127: fix a kmemleak caused in pcf2127_i2c_gather_write

Sasha Levin
2018-11-22T19:56:39Z

From: Xulin Sun <xulin.sun@windriver.com>

[ Upstream commit 9bde0afb7a906f1dabdba37162551565740b862d ]

pcf2127_i2c_gather_write() allocates memory as local variable
for i2c_master_send(), after finishing the master transfer,
the allocated memory should be freed. The kmemleak is reported:

unreferenced object 0xffff80231e7dba80 (size 64):
comm "hwclock", pid 27762, jiffies 4296880075 (age 356.944s)
hex dump (first 32 bytes):
03 00 12 03 19 02 11 13 00 80 98 18 00 00 ff ff ................
00 50 00 00 00 00 00 00 02 00 00 00 00 00 00 00 .P..............
backtrace:
[<ffff000008221398>] create_object+0xf8/0x278
[<ffff000008a96264>] kmemleak_alloc+0x74/0xa0
[<ffff00000821070c>] __kmalloc+0x1ac/0x348
[<ffff0000087ed1dc>] pcf2127_i2c_gather_write+0x54/0xf8
[<ffff0000085fd9d4>] _regmap_raw_write+0x464/0x850
[<ffff0000085fe3f4>] regmap_bulk_write+0x1a4/0x348
[<ffff0000087ed32c>] pcf2127_rtc_set_time+0xac/0xe8
[<ffff0000087eaad8>] rtc_set_time+0x80/0x138
[<ffff0000087ebfb0>] rtc_dev_ioctl+0x398/0x610
[<ffff00000823f2c0>] do_vfs_ioctl+0xb0/0x848
[<ffff00000823fae4>] SyS_ioctl+0x8c/0xa8
[<ffff000008083ac0>] el0_svc_naked+0x34/0x38
[<ffffffffffffffff>] 0xffffffffffffffff

Signed-off-by: Xulin Sun <xulin.sun@windriver.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/rtc/rtc-pcf2127.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/rtc/rtc-pcf2127.c b/drivers/rtc/rtc-pcf2127.c
index 2bfdf638b673..8a3667e761dd 100644
--- a/drivers/rtc/rtc-pcf2127.c
+++ b/drivers/rtc/rtc-pcf2127.c
@@ -237,6 +237,9 @@ static int pcf2127_i2c_gather_write(void *context,
memcpy(buf + 1, val, val_size);

ret = i2c_master_send(client, buf, val_size + 1);
+
+ kfree(buf);
+
if (ret != val_size + 1)
return ret < 0 ? ret : -EIO;

--
2.17.1