From: Thomas Gleixner <tglx@linutronix.de> stable inclusion from stable-6.6.102 commit f07ab7a4b572fa0a6fef26df54c1a1c6710c07ca category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/ICULKF Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 5468c0fbccbb9d156522c50832244a8b722374fb upstream. Failure of the AUX buffer allocation leaks the reference count. Set the reference count to 1 only when the allocation succeeds. Fixes: 45bfb2e50471 ("perf/core: Add AUX area to ring buffer for raw data streams") Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Tengda Wu <wutengda2@huawei.com> --- kernel/events/core.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index 0b09ace2f009..cdef6ae43f4a 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6565,9 +6565,7 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) goto unlock; } - atomic_set(&rb->aux_mmap_count, 1); user_extra = nr_pages; - goto accounting; } @@ -6669,8 +6667,10 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) } else { ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages, event->attr.aux_watermark, flags); - if (!ret) + if (!ret) { + atomic_set(&rb->aux_mmap_count, 1); rb->aux_mmap_locked = extra; + } } unlock: @@ -6680,6 +6680,7 @@ static int perf_mmap(struct file *file, struct vm_area_struct *vma) atomic_inc(&event->mmap_count); } else if (rb) { + /* AUX allocation failed */ atomic_dec(&rb->mmap_count); } aux_unlock: -- 2.34.1