From 07091aade394f690e7b655578140ef84d0e8d7b0 Mon Sep 17 00:00:00 2001 From: Thomas Gleixner Date: Sat, 2 Aug 2025 12:49:48 +0200 Subject: [PATCH] perf/core: Exit early on perf_mmap() fail When perf_mmap() fails to allocate a buffer, it still invokes the event_mapped() callback of the related event. On X86 this might increase the perf_rdpmc_allowed reference counter. But nothing undoes this as perf_mmap_close() is never called in this case, which causes another reference count leak. Return early on failure to prevent that. Fixes: 1e0fb9ec679c ("perf: Add pmu callbacks to track event mapping and unmapping") Signed-off-by: Thomas Gleixner Reviewed-by: Lorenzo Stoakes Cc: stable@vger.kernel.org --- kernel/events/core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/kernel/events/core.c b/kernel/events/core.c index e89e77228591..a2e3591175c6 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7138,6 +7138,9 @@ aux_unlock: mutex_unlock(aux_mutex); mutex_unlock(&event->mmap_mutex); + if (ret) + return ret; + /* * Since pinned accounting is per vm we cannot allow fork() to copy our * vma. @@ -7145,8 +7148,7 @@ aux_unlock: vm_flags_set(vma, VM_DONTCOPY | VM_DONTEXPAND | VM_DONTDUMP); vma->vm_ops = &perf_mmap_vmops; - if (!ret) - ret = map_range(rb, vma); + ret = map_range(rb, vma); mapped = get_mapped(event, event_mapped); if (mapped) -- 2.47.2