github-mirror/linux
1
0
Fork 0
mirror of https://github.com/torvalds/linux.git synced 2026-06-01 02:53:36 +02:00
Code Issues Actions Packages Projects Releases Wiki Activity Graph

cpufreq: intel_pstate: Fix NULL pointer dereference in update_cpu_qos_request()

Browse Source 
The update_cpu_qos_request() function attempts to initialize the 'freq'
variable by dereferencing 'cpudata' before verifying if the 'policy'
is valid.

This issue occurs on systems booted with the "nosmt" parameter, where
all_cpu_data[cpu] is NULL for the SMT sibling threads. As a result,
any call to update_qos_requests() will result in a NULL pointer
dereference as the code will attempt to access pstate.turbo_freq using
the NULL cpudata pointer.

Also, pstate.turbo_freq may be updated by intel_pstate_get_hwp_cap()
after initializing the 'freq' variable, so it is better to defer the
'freq' until intel_pstate_get_hwp_cap() has been called.

Fix this by deferring the 'freq' assignment until after the policy and
driver_data have been validated.

Fixes: ae1bdd23b9 ("cpufreq: intel_pstate: Adjust frequency percentage computations")
Reported-by: Jirka Hladky <jhladky@redhat.com>
Closes: https://lore.kernel.org/all/CAE4VaGDfiPvz3AzrwrwM4kWB3SCkMci25nPO8W1JmTBd=xHzZg@mail.gmail.com/
Signed-off-by: David Arcari <darcari@redhat.com>
Cc: 6.18+ <stable@vger.kernel.org> # 6.18+
[ rjw: Added one paragraph to the changelog ]
Link: https://patch.msgid.link/20260224122106.228116-1-darcari@redhat.com
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
David Arcari 2026-02-24 07:21:06 -05:00 committed by Rafael J. Wysocki
parent 6de23f81a5
commit ab39cc4cb8
1 changed files with 3 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
drivers/cpufreq/intel_pstate.c
View File

@ -1647,8 +1647,8 @@ static ssize_t store_no_turbo(struct kobject *a, struct kobj_attribute *b,
static void update_cpu_qos_request(int cpu, enum freq_qos_req_type type)
{
struct cpudata *cpudata = all_cpu_data[cpu];
unsigned int freq = cpudata->pstate.turbo_freq;
struct freq_qos_request *req;
unsigned int freq;
struct cpufreq_policy *policy __free(put_cpufreq_policy) = cpufreq_cpu_get(cpu);
if (!policy)
@ -1661,6 +1661,8 @@ static void update_cpu_qos_request(int cpu, enum freq_qos_req_type type)
if (hwp_active)
intel_pstate_get_hwp_cap(cpudata);
freq = cpudata->pstate.turbo_freq;
if (type == FREQ_QOS_MIN) {
freq = DIV_ROUND_UP(freq * global.min_perf_pct, 100);
} else {