5.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dan Carpenter <dan.carpenter@xxxxxxxxxx> [ Upstream commit a1e627af32ed60713941cbfc8075d44cad07f6dd ] If the "test->highmem = alloc_pages()" allocation fails then calling __free_pages(test->highmem) will result in a NULL dereference. Also change the error code to -ENOMEM instead of returning success. Fixes: 2661081f5ab9 ("mmc_test: highmem tests") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Link: https://lore.kernel.org/r/8c90be28-67b4-4b0d-a105-034dc72a0b31@stanley.mountain Signed-off-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> --- drivers/mmc/core/mmc_test.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/drivers/mmc/core/mmc_test.c b/drivers/mmc/core/mmc_test.c index cd64e0f23ae54..8fcaec5544ff4 100644 --- a/drivers/mmc/core/mmc_test.c +++ b/drivers/mmc/core/mmc_test.c @@ -3097,13 +3097,13 @@ static ssize_t mtf_test_write(struct file *file, const char __user *buf, test->buffer = kzalloc(BUFFER_SIZE, GFP_KERNEL); #ifdef CONFIG_HIGHMEM test->highmem = alloc_pages(GFP_KERNEL | __GFP_HIGHMEM, BUFFER_ORDER); + if (!test->highmem) { + count = -ENOMEM; + goto free_test_buffer; + } #endif -#ifdef CONFIG_HIGHMEM - if (test->buffer && test->highmem) { -#else if (test->buffer) { -#endif mutex_lock(&mmc_test_lock); mmc_test_run(test, testcase); mutex_unlock(&mmc_test_lock); @@ -3111,6 +3111,7 @@ static ssize_t mtf_test_write(struct file *file, const char __user *buf, #ifdef CONFIG_HIGHMEM __free_pages(test->highmem, BUFFER_ORDER); +free_test_buffer: #endif kfree(test->buffer); kfree(test); -- 2.43.0