[PATCH] x86/vdso: fix incorrect size in munmap during map_vdso failure

[Guilherme Giacomo Simoes <trintaeoitogc@gmail.com>]

In the map_vdso function, if a failure occurs during the installation of
the VVAR mappings, the error path attempts to clean up previously
allocated mappings using do_munmap. However, the cleanup for the VVAR
mapping was incorrectly using image->size (the size of the vDSO text)
instead of the actual size allocated for the VVAR area.

Replace the incorrect image->size parameter with the constant
VDSO_NR_PAGES * PAGE_SIZE in the do_munmap call. Ensure the unmap size
exactly matches the size used during the vdso_install_vvar_mapping()
phase to provide a symmetrical and complete teardown of the memory
region.

Signed-off-by: Guilherme Giacomo Simoes <trintaeoitogc@gmail.com>
---
 arch/x86/entry/vdso/vma.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/entry/vdso/vma.c b/arch/x86/entry/vdso/vma.c
index a6bfcc8243cd..d903bce24f15 100644
--- a/arch/x86/entry/vdso/vma.c
+++ b/arch/x86/entry/vdso/vma.c
@@ -178,7 +178,7 @@ static int map_vdso(const struct vdso_image *image, unsigned long addr)
 	if (IS_ERR(vma)) {
 		ret = PTR_ERR(vma);
 		do_munmap(mm, text_start, image->size, NULL);
-		do_munmap(mm, addr, image->size, NULL);
+		do_munmap(mm, addr, VDSO_NR_PAGES * PAGE_SIZE, NULL);
 		goto up_fail;
 	}
 
-- 
2.52.0