kmap leak fix for x86_32 kdump

copy_oldmem_page should not return leaving a page frame from the
previous kernel mapped.

Signed-off-by: Fernando Luis Vázquez Cao <fernando@oss.ntt.co.jp>
Acked-by: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 0 deletions

diff --git a/arch/x86/kernel/crash_dump_32.c b/arch/x86/kernel/crash_dump_32.c
index 32e75d0731a9..72d0c56c1b48 100644
--- a/arch/x86/kernel/crash_dump_32.c
+++ b/arch/x86/kernel/crash_dump_32.c
@@ -47,6 +47,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
                 if (!kdump_buf_page) {
                         printk(KERN_WARNING "Kdump: Kdump buffer page not"
                                 " allocated\n");
+                        kunmap_atomic(vaddr, KM_PTE0);
                         return -EFAULT;
                 }
                 copy_page(kdump_buf_page, vaddr);