[PATCH] mm/mprotect: Fix do_mprotect_pkey() limit check

From: Liam R. Howlett
Date: Tue Jun 06 2023 - 14:30:20 EST


The return of do_mprotect_pkey() can still be incorrectly returned as
success if there is a gap that spans to or beyond the end address passed
in. Update the check to ensure that the end address has indeed been
seen.

Link: https://lore.kernel.org/all/CABi2SkXjN+5iFoBhxk71t3cmunTk-s=rB4T7qo0UQRh17s49PQ@xxxxxxxxxxxxxx/
Fixes: 82f951340f25 ("mm/mprotect: fix do_mprotect_pkey() return on error")
Reported-by: Jeff Xu <jeffxu@xxxxxxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Liam R. Howlett <Liam.Howlett@xxxxxxxxxx>
---
mm/mprotect.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/mprotect.c b/mm/mprotect.c
index 92d3d3ca390a..c59e7561698c 100644
--- a/mm/mprotect.c
+++ b/mm/mprotect.c
@@ -867,7 +867,7 @@ static int do_mprotect_pkey(unsigned long start, size_t len,
}
tlb_finish_mmu(&tlb);

- if (!error && vma_iter_end(&vmi) < end)
+ if (!error && tmp < end)
error = -ENOMEM;

out:
--
2.39.2