From 3b8db39fad98cbb1d36e079236a446fad710daea Mon Sep 17 00:00:00 2001 From: David Hildenbrand Date: Mon, 28 Jun 2021 19:38:35 -0700 Subject: [PATCH] mm: ignore MAP_EXECUTABLE in ksys_mmap_pgoff() Let's also remove masking off MAP_EXECUTABLE from ksys_mmap_pgoff(): the last in-tree occurrence of MAP_EXECUTABLE is now in LEGACY_MAP_MASK, which accepts the flag e.g., for MAP_SHARED_VALIDATE; however, the flag is ignored throughout the kernel now. Add a comment to LEGACY_MAP_MASK stating that MAP_EXECUTABLE is ignored. Link: https://lkml.kernel.org/r/20210421093453.6904-4-david@redhat.com Signed-off-by: David Hildenbrand Acked-by: "Eric W. Biederman" Reviewed-by: Kees Cook Cc: Alexander Shishkin Cc: Alexander Viro Cc: Arnaldo Carvalho de Melo Cc: Borislav Petkov Cc: Catalin Marinas Cc: Don Zickus Cc: Feng Tang Cc: Greg Ungerer Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kevin Brodsky Cc: Mark Rutland Cc: Michal Hocko Cc: Mike Rapoport Cc: Namhyung Kim Cc: Peter Zijlstra Cc: Thomas Gleixner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/mman.h | 2 ++ mm/mmap.c | 2 +- mm/nommu.c | 2 +- 3 files changed, 4 insertions(+), 2 deletions(-) diff --git a/include/linux/mman.h b/include/linux/mman.h index 629cefc4ecba..ebb09a964272 100644 --- a/include/linux/mman.h +++ b/include/linux/mman.h @@ -31,6 +31,8 @@ /* * The historical set of flags that all mmap implementations implicitly * support when a ->mmap_validate() op is not provided in file_operations. + * + * MAP_EXECUTABLE is completely ignored throughout the kernel. */ #define LEGACY_MAP_MASK (MAP_SHARED \ | MAP_PRIVATE \ diff --git a/mm/mmap.c b/mm/mmap.c index 0584e540246e..f9a61f7dc540 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1633,7 +1633,7 @@ unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len, return PTR_ERR(file); } - flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE); + flags &= ~MAP_DENYWRITE; retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff); out_fput: diff --git a/mm/nommu.c b/mm/nommu.c index 85a3a68dffb6..affda71641ca 100644 --- a/mm/nommu.c +++ b/mm/nommu.c @@ -1296,7 +1296,7 @@ unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len, goto out; } - flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE); + flags &= ~MAP_DENYWRITE; retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff);