This is a note to let you know that I've just added the patch titled
PM: hibernate: Use __get_safe_page() rather than touching the list
to the 4.19-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pm-hibernate-use-__get_safe_page-rather-than-touching-the-list.patch
and it can be found in the queue-4.19 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From f0c7183008b41e92fa676406d87f18773724b48b Mon Sep 17 00:00:00 2001
From: Brian Geffon <bgeffon@xxxxxxxxxx>
Date: Thu, 21 Sep 2023 13:00:45 -0400
Subject: PM: hibernate: Use __get_safe_page() rather than touching the list
From: Brian Geffon <bgeffon@xxxxxxxxxx>
commit f0c7183008b41e92fa676406d87f18773724b48b upstream.
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@xxxxxxxxxx>
Fixes: 8357376d3df2 ("[PATCH] swsusp: Improve handling of highmem")
Cc: All applicable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
kernel/power/snapshot.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -2376,8 +2376,9 @@ static void *get_highmem_page_buffer(str
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;
@@ -2557,8 +2558,9 @@ static void *get_buffer(struct memory_bi
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;
Patches currently in stable-queue which might be from bgeffon@xxxxxxxxxx are
queue-4.19/pm-hibernate-clean-up-sync_read-handling-in-snapshot_write_next.patch
queue-4.19/pm-hibernate-use-__get_safe_page-rather-than-touching-the-list.patch
