2022-09-16 07:25:02

by Dan Carpenter

[permalink] [raw]
Subject: drivers/fpga/intel-m10-bmc-sec-update.c:103 flash_count_show() warn: possible memory leak of 'flash_buf'

tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 3245cb65fd91cd514801bf91f5a3066d562f0ac4
commit: 154afa5c31cd2de5e6c2c4f35eee390993ee345a fpga: m10bmc-sec: expose max10 flash update count
config: m68k-randconfig-m031-20220914 (https://download.01.org/0day-ci/archive/20220916/[email protected]/config)
compiler: m68k-linux-gcc (GCC) 12.1.0

If you fix the issue, kindly add following tag where applicable
Reported-by: kernel test robot <[email protected]>
Reported-by: Dan Carpenter <[email protected]>

smatch warnings:
drivers/fpga/intel-m10-bmc-sec-update.c:103 flash_count_show() warn: possible memory leak of 'flash_buf'

vim +/flash_buf +103 drivers/fpga/intel-m10-bmc-sec-update.c

154afa5c31cd2d Russ Weight 2022-06-06 83 static ssize_t flash_count_show(struct device *dev,
154afa5c31cd2d Russ Weight 2022-06-06 84 struct device_attribute *attr, char *buf)
154afa5c31cd2d Russ Weight 2022-06-06 85 {
154afa5c31cd2d Russ Weight 2022-06-06 86 struct m10bmc_sec *sec = dev_get_drvdata(dev);
154afa5c31cd2d Russ Weight 2022-06-06 87 unsigned int stride, num_bits;
154afa5c31cd2d Russ Weight 2022-06-06 88 u8 *flash_buf;
154afa5c31cd2d Russ Weight 2022-06-06 89 int cnt, ret;
154afa5c31cd2d Russ Weight 2022-06-06 90
154afa5c31cd2d Russ Weight 2022-06-06 91 stride = regmap_get_reg_stride(sec->m10bmc->regmap);
154afa5c31cd2d Russ Weight 2022-06-06 92 num_bits = FLASH_COUNT_SIZE * 8;
154afa5c31cd2d Russ Weight 2022-06-06 93
154afa5c31cd2d Russ Weight 2022-06-06 94 flash_buf = kmalloc(FLASH_COUNT_SIZE, GFP_KERNEL);
154afa5c31cd2d Russ Weight 2022-06-06 95 if (!flash_buf)
154afa5c31cd2d Russ Weight 2022-06-06 96 return -ENOMEM;
154afa5c31cd2d Russ Weight 2022-06-06 97
154afa5c31cd2d Russ Weight 2022-06-06 98 if (FLASH_COUNT_SIZE % stride) {
154afa5c31cd2d Russ Weight 2022-06-06 99 dev_err(sec->dev,
154afa5c31cd2d Russ Weight 2022-06-06 100 "FLASH_COUNT_SIZE (0x%x) not aligned to stride (0x%x)\n",
154afa5c31cd2d Russ Weight 2022-06-06 101 FLASH_COUNT_SIZE, stride);
154afa5c31cd2d Russ Weight 2022-06-06 102 WARN_ON_ONCE(1);

do this check before the kmalloc()?

154afa5c31cd2d Russ Weight 2022-06-06 @103 return -EINVAL;
154afa5c31cd2d Russ Weight 2022-06-06 104 }
154afa5c31cd2d Russ Weight 2022-06-06 105
154afa5c31cd2d Russ Weight 2022-06-06 106 ret = regmap_bulk_read(sec->m10bmc->regmap, STAGING_FLASH_COUNT,
154afa5c31cd2d Russ Weight 2022-06-06 107 flash_buf, FLASH_COUNT_SIZE / stride);
154afa5c31cd2d Russ Weight 2022-06-06 108 if (ret) {
154afa5c31cd2d Russ Weight 2022-06-06 109 dev_err(sec->dev,
154afa5c31cd2d Russ Weight 2022-06-06 110 "failed to read flash count: %x cnt %x: %d\n",
154afa5c31cd2d Russ Weight 2022-06-06 111 STAGING_FLASH_COUNT, FLASH_COUNT_SIZE / stride, ret);
154afa5c31cd2d Russ Weight 2022-06-06 112 goto exit_free;
154afa5c31cd2d Russ Weight 2022-06-06 113 }
154afa5c31cd2d Russ Weight 2022-06-06 114 cnt = num_bits - bitmap_weight((unsigned long *)flash_buf, num_bits);
154afa5c31cd2d Russ Weight 2022-06-06 115
154afa5c31cd2d Russ Weight 2022-06-06 116 exit_free:
154afa5c31cd2d Russ Weight 2022-06-06 117 kfree(flash_buf);
154afa5c31cd2d Russ Weight 2022-06-06 118
154afa5c31cd2d Russ Weight 2022-06-06 119 return ret ? : sysfs_emit(buf, "%u\n", cnt);
154afa5c31cd2d Russ Weight 2022-06-06 120 }

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