GitHub-Mirror/Star64_linux
2
0
Fork 0
mirror of https://github.com/Fishwaldo/Star64_linux.git synced 2025-03-16 04:04:06 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions

sched/core: Fix NULL pointer access fault in sched_setaffinity() with non-SMP configs

Browse source 
The kernel commit 9a5418bc48 ("sched/core: Use kfree_rcu() in
do_set_cpus_allowed()") introduces a bug for kernels built with non-SMP
configs. Calling sched_setaffinity() on such a uniprocessor kernel will
cause cpumask_copy() to be called with a NULL pointer leading to general
protection fault. This is not really a problem in real use cases as
there aren't that many uniprocessor kernel configs in use and calling
sched_setaffinity() on such a uniprocessor system doesn't make sense.

Fix this problem by making sure cpumask_copy() will not be called in
such a case.

Fixes: 9a5418bc48 ("sched/core: Use kfree_rcu() in do_set_cpus_allowed()")
Reported-by: kernel test robot <yujie.liu@intel.com>
Signed-off-by: Waiman Long <longman@redhat.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20230115193122.563036-1-longman@redhat.com
This commit is contained in:
Waiman Long 2023-01-15 14:31:22 -05:00 • committed by Ingo Molnar
parent da07d2f9c1
commit 5657c11678
1 changed files with 8 additions and 2 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

10
kernel/sched/core.c
View file

@ -8290,12 +8290,18 @@ long sched_setaffinity(pid_t pid, const struct cpumask *in_mask)
if (retval)
goto out_put_task;
/*
* With non-SMP configs, user_cpus_ptr/user_mask isn't used and
* alloc_user_cpus_ptr() returns NULL.
*/
user_mask = alloc_user_cpus_ptr(NUMA_NO_NODE);
if (IS_ENABLED(CONFIG_SMP) && !user_mask) {
if (user_mask) {
cpumask_copy(user_mask, in_mask);
} else if (IS_ENABLED(CONFIG_SMP)) {
retval = -ENOMEM;
goto out_put_task;
}
cpumask_copy(user_mask, in_mask);
ac = (struct affinity_context){
.new_mask = in_mask,
.user_mask = user_mask,