From f0c7183008b41e92fa676406d87f18773724b48b Mon Sep 17 00:00:00 2001
From: Brian Geffon <bgeffon@google.com>
Date: Thu, 21 Sep 2023 13:00:45 -0400
Subject: [PATCH] PM: hibernate: Use __get_safe_page() rather than touching the list
Git-commit: f0c7183008b41e92fa676406d87f18773724b48b
Patch-mainline: v6.7-rc1
References: git-fixes
We found at least one situation where the safe pages list was empty and
get_buffer() would gladly try to use a NULL pointer.
Signed-off-by: Brian Geffon <bgeffon@google.com>
Fixes: 8357376d3df2 ("[PATCH] swsusp: Improve handling of highmem")
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
kernel/power/snapshot.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index 87e9f7e2bdc0..acd2e49b9ac8 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -2545,8 +2545,9 @@ static void *get_highmem_page_buffer(struct page *page,
pbe->copy_page = tmp;
} else {
/* Copy of the page will be stored in normal memory */
- kaddr = safe_pages_list;
- safe_pages_list = safe_pages_list->next;
+ kaddr = __get_safe_page(ca->gfp_mask);
+ if (!kaddr)
+ return ERR_PTR(-ENOMEM);
pbe->copy_page = virt_to_page(kaddr);
}
pbe->next = highmem_pblist;
@@ -2750,8 +2751,9 @@ static void *get_buffer(struct memory_bitmap *bm, struct chain_allocator *ca)
return ERR_PTR(-ENOMEM);
}
pbe->orig_address = page_address(page);
- pbe->address = safe_pages_list;
- safe_pages_list = safe_pages_list->next;
+ pbe->address = __get_safe_page(ca->gfp_mask);
+ if (!pbe->address)
+ return ERR_PTR(-ENOMEM);
pbe->next = restore_pblist;
restore_pblist = pbe;
return pbe->address;
--
2.35.3