X-Git-Url: https://git.kernelconcepts.de/?p=karo-tx-linux.git;a=blobdiff_plain;f=mm%2Fshmem.c;h=6540e598244412023db650412062604b704b58b3;hp=b0aa6075d164df9ae4766876cc823394abaebc6d;hb=d041353dc98a6339182cd6f628b4c8f111278cb3;hpb=19c6e12c07ceab2ff5d5ec97354b893ab386c41c

diff --git a/mm/shmem.c b/mm/shmem.c
index b0aa6075d164..6540e5982444 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -1022,7 +1022,11 @@ static int shmem_setattr(struct dentry *dentry, struct iattr *attr)
 			 */
 			if (IS_ENABLED(CONFIG_TRANSPARENT_HUGE_PAGECACHE)) {
 				spin_lock(&sbinfo->shrinklist_lock);
-				if (list_empty(&info->shrinklist)) {
+				/*
+				 * _careful to defend against unlocked access to
+				 * ->shrink_list in shmem_unused_huge_shrink()
+				 */
+				if (list_empty_careful(&info->shrinklist)) {
 					list_add_tail(&info->shrinklist,
 							&sbinfo->shrinklist);
 					sbinfo->shrinklist_len++;
@@ -1817,7 +1821,11 @@ alloc_nohuge:		page = shmem_alloc_and_acct_page(gfp, info, sbinfo,
 			 * to shrink under memory pressure.
 			 */
 			spin_lock(&sbinfo->shrinklist_lock);
-			if (list_empty(&info->shrinklist)) {
+			/*
+			 * _careful to defend against unlocked access to
+			 * ->shrink_list in shmem_unused_huge_shrink()
+			 */
+			if (list_empty_careful(&info->shrinklist)) {
 				list_add_tail(&info->shrinklist,
 						&sbinfo->shrinklist);
 				sbinfo->shrinklist_len++;