[PATCH 5.18 0898/1095] s390/crash: fix incorrect number of bytes to copy to user space

Greg Kroah-Hartman
2022-08-15T22:45:27Z

From: Alexander Gordeev <agordeev@linux.ibm.com>

[ 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@infradead.org>
Fixes: df9694c7975f ("s390/dump: streamline oldmem copy functions")
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 28124d0fa1d5..f8ebdd70dd31 100644
--- a/arch/s390/kernel/crash_dump.c
+++ b/arch/s390/kernel/crash_dump.c
@@ -199,7 +199,7 @@ 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