| Message ID | 20221109093120.3128541-1-zengheng4@huawei.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2] gpiolib: fix memory leak in gpiochip_setup_dev | expand |
diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 4756ea08894f..fa659af86d07 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -539,6 +539,7 @@ static int gpiochip_setup_dev(struct gpio_device *gdev) err_remove_device: gcdev_unregister(gdev); + kfree(gdev->dev.p); return ret; }
gcdev_register & gcdev_unregister call device_add & device_del to request/release source. But in device_add, the dev->p allocated by device_private_init is not released by device_del. So when calling gcdev_unregister to release gdev, it needs put_device to release dev in the following. Otherwise, kmemleak would report memory leak such as below: unreferenced object 0xffff88810b406400 (size 512): comm "python3", pid 1682, jiffies 4295346908 (age 24.090s) hex dump (first 32 bytes): 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N.......... ff ff ff ff ff ff ff ff a0 5e 23 90 ff ff ff ff .........^#..... backtrace: [<00000000a58ee5fe>] kmalloc_trace+0x22/0x110 [<0000000045fe2058>] device_add+0xb34/0x1130 [<00000000d778b45f>] cdev_device_add+0x83/0xe0 [<0000000089f948ed>] gpiolib_cdev_register+0x73/0xa0 [<00000000a3a8a316>] gpiochip_setup_dev+0x1c/0x70 [<00000000787227b4>] gpiochip_add_data_with_key+0x10f6/0x1bf0 [<000000009ac5742c>] devm_gpiochip_add_data_with_key+0x2e/0x80 [<00000000bf2b23d9>] xra1403_probe+0x192/0x1b0 [gpio_xra1403] [<000000005b5ef2d4>] spi_probe+0xe1/0x140 [<000000002b26f6f1>] really_probe+0x17c/0x3f0 [<00000000dd2dad9c>] __driver_probe_device+0xe3/0x170 [<000000005ca60d2a>] device_driver_attach+0x34/0x80 [<00000000e9db90db>] bind_store+0x10b/0x1a0 [<00000000e2650f8a>] drv_attr_store+0x49/0x70 [<0000000080a80b2b>] sysfs_kf_write+0x8c/0xb0 [<00000000a28b45b9>] kernfs_fop_write_iter+0x216/0x2e0 unreferenced object 0xffff888100de9800 (size 512): comm "python3", pid 264, jiffies 4294737615 (age 33.514s) hex dump (first 32 bytes): 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N.......... ff ff ff ff ff ff ff ff a0 5e 63 a1 ff ff ff ff .........^c..... backtrace: [<00000000bcc571d0>] kmalloc_trace+0x22/0x110 [<00000000eeb06124>] device_add+0xb34/0x1130 [<000000007e5cd2fd>] cdev_device_add+0x83/0xe0 [<000000008f6bcd3a>] gpiolib_cdev_register+0x73/0xa0 [<0000000012c93b24>] gpiochip_setup_dev+0x1c/0x70 [<00000000a24b646a>] gpiochip_add_data_with_key+0x10f6/0x1bf0 [<000000000c225212>] tpic2810_probe+0x16e/0x196 [gpio_tpic2810] [<00000000b52d04ff>] i2c_device_probe+0x651/0x680 [<0000000058d3ff6b>] really_probe+0x17c/0x3f0 [<00000000586f43d3>] __driver_probe_device+0xe3/0x170 [<000000003f428602>] device_driver_attach+0x34/0x80 [<0000000040e91a1b>] bind_store+0x10b/0x1a0 [<00000000c1d990b9>] drv_attr_store+0x49/0x70 [<00000000a23bfc22>] sysfs_kf_write+0x8c/0xb0 [<00000000064e6572>] kernfs_fop_write_iter+0x216/0x2e0 [<00000000026ce093>] vfs_write+0x658/0x810 Because at the point of gpiochip_setup_dev here, where dev.release does not set yet, calling put_device would cause the warning of no release function and double-free in the following fault handler route (when kfree dev_name). So directly calling kfree to release dev->p here in case of memory leak. Fixes: 159f3cd92f17 ("gpiolib: Defer gpio device setup until after gpiolib initialization") Signed-off-by: Zeng Heng <zengheng4@huawei.com> --- changes in v2: - correct fix tag --- drivers/gpio/gpiolib.c | 1 + 1 file changed, 1 insertion(+)