| Message ID | 20221015130424.1923706-2-fabien.parent@linaro.org (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | [v2,1/3] cpufreq: qcom: fix memory leak in error path | expand |
diff --git a/drivers/cpufreq/qcom-cpufreq-nvmem.c b/drivers/cpufreq/qcom-cpufreq-nvmem.c index 3bd38acde4b9..82e0339d7722 100644 --- a/drivers/cpufreq/qcom-cpufreq-nvmem.c +++ b/drivers/cpufreq/qcom-cpufreq-nvmem.c @@ -265,7 +265,8 @@ static int qcom_cpufreq_probe(struct platform_device *pdev) struct nvmem_cell *speedbin_nvmem; struct device_node *np; struct device *cpu_dev; - char *pvs_name = "speedXX-pvsXX-vXX"; + char pvs_name_buffer[] = "speedXX-pvsXX-vXX"; + char *pvs_name = pvs_name_buffer; unsigned cpu; const struct of_device_id *match; int ret;
This commit fixes a kernel oops because of a write in some read-only memory: [ 9.068287] Unable to handle kernel write to read-only memory at virtual address ffff800009240ad8 ..snip.. [ 9.138790] Internal error: Oops: 9600004f [#1] PREEMPT SMP ..snip.. [ 9.269161] Call trace: [ 9.276271] __memcpy+0x5c/0x230 [ 9.278531] snprintf+0x58/0x80 [ 9.282002] qcom_cpufreq_msm8939_name_version+0xb4/0x190 [ 9.284869] qcom_cpufreq_probe+0xc8/0x39c ..snip.. The following line defines a pointer that point to a char buffer stored in read-only memory: char *pvs_name = "speedXX-pvsXX-vXX"; This pointer is meant to hold a template "speedXX-pvsXX-vXX" where the XX values get overridden by the qcom_cpufreq_krait_name_version function. Since the template is actually stored in read-only memory, when the function executes the following call we get an oops: snprintf(*pvs_name, sizeof("speedXX-pvsXX-vXX"), "speed%d-pvs%d-v%d", speed, pvs, pvs_ver); To fix this issue, we instead store the template name onto the stack by using the following syntax: char pvs_name_buffer[] = "speedXX-pvsXX-vXX"; Because the `pvs_name` needs to be able to be assigned to NULL, the template buffer is stored in the pvs_name_buffer and not under the pvs_name variable. Fixes: a8811ec764f9 ("cpufreq: qcom: Add support for krait based socs") Signed-off-by: Fabien Parent <fabien.parent@linaro.org> --- v2: * Added missing "Fixes" tag * Rebased to not depend on another non-bug fix patch drivers/cpufreq/qcom-cpufreq-nvmem.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)