Merge tag 'v5.16-rc2' into devel

Linux 5.16-rc2 is needed because nonurgent fixes headed
for next are strongly textually dependent on a fix that
was applied for rc2.

Signed-off-by: Linus Walleij <[email protected]>

1 files changed, 12 insertions, 8 deletions

diff --git a/fs/proc/vmcore.c b/fs/proc/vmcore.c
index 30a3b66f475a..509f85148fee 100644
--- a/fs/proc/vmcore.c
+++ b/fs/proc/vmcore.c
@@ -154,9 +154,13 @@ ssize_t read_from_oldmem(char *buf, size_t count,
 			nr_bytes = count;
 
 		/* If pfn is not ram, return zeros for sparse dump files */
-		if (!pfn_is_ram(pfn))
-			memset(buf, 0, nr_bytes);
-		else {
+		if (!pfn_is_ram(pfn)) {
+			tmp = 0;
+			if (!userbuf)
+				memset(buf, 0, nr_bytes);
+			else if (clear_user(buf, nr_bytes))
+				tmp = -EFAULT;
+		} else {
 			if (encrypted)
 				tmp = copy_oldmem_page_encrypted(pfn, buf,
 								 nr_bytes,
@@ -165,12 +169,12 @@ ssize_t read_from_oldmem(char *buf, size_t count,
 			else
 				tmp = copy_oldmem_page(pfn, buf, nr_bytes,
 						       offset, userbuf);
-
-			if (tmp < 0) {
-				up_read(&vmcore_cb_rwsem);
-				return tmp;
-			}
 		}
+		if (tmp < 0) {
+			up_read(&vmcore_cb_rwsem);
+			return tmp;
+		}
+
 		*ppos += nr_bytes;
 		count -= nr_bytes;
 		buf += nr_bytes;