[PATCH 5.15 621/779] s390/crash: fix incorrect number of bytes to copy to user space

[Greg Kroah-Hartman]

From: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>

[ Upstream commit f6749da17a34eb08c9665f072ce7c812ff68aad2 ]

The number of bytes in a chunk is correctly calculated, but instead
the total number of bytes is passed to copy_to_user_real() function.

Reported-by: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Fixes: df9694c7975f ("s390/dump: streamline oldmem copy functions")
Signed-off-by: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 arch/s390/kernel/crash_dump.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c
index 199f136d1644..f17ad2daab07 100644
--- a/arch/s390/kernel/crash_dump.c
+++ b/arch/s390/kernel/crash_dump.c
@@ -198,7 +198,7 @@ static int copy_oldmem_user(void __user *dst, unsigned long src, size_t count)
 			} else {
 				len = count;
 			}
-			rc = copy_to_user_real(dst, src, count);
+			rc = copy_to_user_real(dst, src, len);
 			if (rc)
 				return rc;
 		}
-- 
2.35.1