From 9ab96b524dce598c041388a599e3a227c7a7926c Mon Sep 17 00:00:00 2001 From: Muchun Song Date: Mon, 6 Jan 2025 11:31:17 +0800 Subject: [PATCH] hugetlb: fix NULL pointer dereference in trace_hugetlbfs_alloc_inode hugetlb_file_setup() will pass a NULL @dir to hugetlbfs_get_inode(), so we will access a NULL pointer for @dir. Fix it and set __entry->dr to 0 if @dir is NULL. Because ->i_ino cannot be 0 (see get_next_ino()), there is no confusing if user sees a 0 inode number. Link: https://lkml.kernel.org/r/20250106033118.4640-1-songmuchun@bytedance.com Fixes: 318580ad7f28 ("hugetlbfs: support tracepoint") Signed-off-by: Muchun Song Reported-by: Cheung Wall Closes: https://lore.kernel.org/linux-mm/02858D60-43C1-4863-A84F-3C76A8AF1F15@linux.dev/T/# Reviewed-by: Hongbo Li Cc: cheung wall Cc: Christian Brauner Cc: Signed-off-by: Andrew Morton --- include/trace/events/hugetlbfs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/include/trace/events/hugetlbfs.h b/include/trace/events/hugetlbfs.h index 8331c904a9ba87..59605dfaeeb43d 100644 --- a/include/trace/events/hugetlbfs.h +++ b/include/trace/events/hugetlbfs.h @@ -23,7 +23,7 @@ TRACE_EVENT(hugetlbfs_alloc_inode, TP_fast_assign( __entry->dev = inode->i_sb->s_dev; __entry->ino = inode->i_ino; - __entry->dir = dir->i_ino; + __entry->dir = dir ? dir->i_ino : 0; __entry->mode = mode; ),