diff options
| author | Vernon Yang <yanglincheng@kylinos.cn> | 2026-09-09 10:58:03 +0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2026-10-06 17:38:56 -0700 |
| commit | 9010383e71e6ce75fcd3c8f87133c8ce6c0e6ab4 (patch) | |
| tree | 04098300624ae74ce6e6744c0318e7875e06f6c3 /include | |
| parent | ba2f1f92ddfabd340c9248fd2380104f717ee8b1 (diff) | |
mm: khugepaged: fix folio is used after folio_put/unlock()
On the rollback path, folio_put() has already dropped the last reference
of new_folio. On the success path, new_folio is already unlocked and can
be freed concurrently. The trace_mm_khugepaged_collapse_file() is left
with a dangling folio pointer.
So using the folio_pfn() before dropping the reference, closing
use-after-free window.
Link: https://lore.kernel.org/20260909025804.3233645-4-vernon2gm@gmail.com
Fixes: 4c9473e87e75 ("mm/khugepaged: add tracepoint to collapse_file()")
Signed-off-by: Vernon Yang <yanglincheng@kylinos.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Cc: Barry Song <baohua@kernel.org>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Cc: <stable@vger.kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/trace/events/huge_memory.h | 6 |
1 files changed, 3 insertions, 3 deletions
diff --git a/include/trace/events/huge_memory.h b/include/trace/events/huge_memory.h index fa828967e1fb..5fb4d92cfd84 100644 --- a/include/trace/events/huge_memory.h +++ b/include/trace/events/huge_memory.h @@ -211,10 +211,10 @@ TRACE_EVENT(mm_khugepaged_scan_file, ); TRACE_EVENT(mm_khugepaged_collapse_file, - TP_PROTO(struct mm_struct *mm, struct folio *new_folio, pgoff_t index, + TP_PROTO(struct mm_struct *mm, unsigned long new_pfn, pgoff_t index, unsigned long addr, bool is_shmem, struct file *file, int nr, int result), - TP_ARGS(mm, new_folio, index, addr, is_shmem, file, nr, result), + TP_ARGS(mm, new_pfn, index, addr, is_shmem, file, nr, result), TP_STRUCT__entry( __field(struct mm_struct *, mm) __field(unsigned long, hpfn) @@ -228,7 +228,7 @@ TRACE_EVENT(mm_khugepaged_collapse_file, TP_fast_assign( __entry->mm = mm; - __entry->hpfn = new_folio ? folio_pfn(new_folio) : -1; + __entry->hpfn = new_pfn; __entry->index = index; __entry->addr = addr; __entry->is_shmem = is_shmem; |