[linux-next][PATCH 1/1] gpio: Delete excess allocated label memory

From: Xiaolei Wang
Date: Sat Feb 17 2024 - 09:31:31 EST


The changes in commit 1f2bcb8c8ccd ("gpio: protect the
descriptor label with SRCU"), desc_set_label has already
allocated memory space for the label, so there is no need
to allocate it again. otherwise memory leaks will be
introduced.

unreferenced object 0xffff0000c3e4d0c0 (size 32):
comm "kworker/u16:4", pid 60, jiffies 4294894555
hex dump (first 32 bytes):
72 65 67 75 6c 61 74 6f 72 2d 63 61 6e 32 2d 73 regulator-can2-s
74 62 79 00 00 00 ff ff ff ff ff ff eb db ff ff tby.............
backtrace (crc 2c3a0350):
[<00000000e93c5cf4>] kmemleak_alloc+0x34/0x40
[<0000000097a2657f>] __kmalloc_node_track_caller+0x2c4/0x524
[<000000000dd1c057>] kstrdup+0x4c/0x98
[<00000000b513a96a>] kstrdup_const+0x34/0x40
[<000000008a7f0feb>] gpiod_request_commit+0xdc/0x358
[<00000000fc71ad64>] gpiod_request+0xd8/0x204
[<00000000fa24b091>] gpiod_find_and_request+0x170/0x780
[<0000000086ecf92d>] gpiod_get_index+0x70/0xe0
[<000000004aef97f9>] gpiod_get_optional+0x18/0x30
[<00000000312f1b25>] reg_fixed_voltage_probe+0x58c/0xad8
[<00000000e6f47635>] platform_probe+0xc4/0x198
[<00000000cf78fbdb>] really_probe+0x204/0x5a8
[<00000000e28d05ec>] __driver_probe_device+0x158/0x2c4
[<00000000e4fe452b>] driver_probe_device+0x60/0x18c
[<00000000479fcf5d>] __device_attach_driver+0x168/0x208
[<000000007d389f38>] bus_for_each_drv+0x104/0x190

Fixes: 1f2bcb8c8ccd ("gpio: protect the descriptor label with SRCU")
Signed-off-by: Xiaolei Wang <xiaolei.wang@xxxxxxxxxxxxx>
---
drivers/gpio/gpiolib.c | 6 ------
1 file changed, 6 deletions(-)

diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
index 02be0ba1a402..32191547dece 100644
--- a/drivers/gpio/gpiolib.c
+++ b/drivers/gpio/gpiolib.c
@@ -2250,12 +2250,6 @@ static int gpiod_request_commit(struct gpio_desc *desc, const char *label)
if (test_and_set_bit(FLAG_REQUESTED, &desc->flags))
return -EBUSY;

- if (label) {
- label = kstrdup_const(label, GFP_KERNEL);
- if (!label)
- return -ENOMEM;
- }
-
/* NOTE: gpio_request() can be called in early boot,
* before IRQs are enabled, for non-sleeping (SOC) GPIOs.
*/
--
2.25.1