4.19-stable review patch. If anyone has any objections, please let me know.
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From: Brian Geffon bgeffon@google.com
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@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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- 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;