6.15-stable review patch. If anyone has any objections, please let me know.
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From: Thomas Gleixner tglx@linutronix.de
commit 54473e0ef849f44e5ee43e6d6746c27030c3825b upstream.
A recent overhaul sets the return value to 0 unconditionally after the allocations, which causes reference count leaks and corrupts the user->vm accounting.
Preserve the AUX buffer allocation failure return value, so that the subsequent code works correctly.
Fixes: 0983593f32c4 ("perf/core: Lift event->mmap_mutex in perf_mmap()") 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 --- kernel/events/core.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
--- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7052,6 +7052,7 @@ static int perf_mmap(struct file *file, perf_event_update_time(event); perf_event_init_userpage(event); perf_event_update_userpage(event); + ret = 0; } else { ret = rb_alloc_aux(rb, event, vma->vm_pgoff, nr_pages, event->attr.aux_watermark, flags); @@ -7059,8 +7060,6 @@ static int perf_mmap(struct file *file, rb->aux_mmap_locked = extra; }
- ret = 0; - unlock: if (!ret) { atomic_long_add(user_extra, &user->locked_vm);