From: David Hildenbrand <david@xxxxxxxxxx> Subject: 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@xxxxxxxxxx Signed-off-by: David Hildenbrand <david@xxxxxxxxxx> Acked-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx> Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx> Cc: Alexander Shishkin <alexander.shishkin@xxxxxxxxxxxxxxx> Cc: Alexander Viro <viro@xxxxxxxxxxxxxxxxxx> Cc: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx> Cc: Borislav Petkov <bp@xxxxxxxxx> Cc: Catalin Marinas <catalin.marinas@xxxxxxx> Cc: Don Zickus <dzickus@xxxxxxxxxx> Cc: Feng Tang <feng.tang@xxxxxxxxx> Cc: Greg Ungerer <gerg@xxxxxxxxxxxxxx> Cc: "H. Peter Anvin" <hpa@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxxxxx> Cc: Jiri Olsa <jolsa@xxxxxxxxxx> Cc: Kevin Brodsky <Kevin.Brodsky@xxxxxxx> Cc: Mark Rutland <mark.rutland@xxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Mike Rapoport <rppt@xxxxxxxxxx> Cc: Namhyung Kim <namhyung@xxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- include/linux/mman.h | 2 ++ mm/mmap.c | 2 +- mm/nommu.c | 2 +- 3 files changed, 4 insertions(+), 2 deletions(-) --- a/include/linux/mman.h~mm-ignore-map_executable-in-ksys_mmap_pgoff +++ a/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 \ --- a/mm/mmap.c~mm-ignore-map_executable-in-ksys_mmap_pgoff +++ a/mm/mmap.c @@ -1633,7 +1633,7 @@ unsigned long ksys_mmap_pgoff(unsigned l return PTR_ERR(file); } - flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE); + flags &= ~MAP_DENYWRITE; retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff); out_fput: --- a/mm/nommu.c~mm-ignore-map_executable-in-ksys_mmap_pgoff +++ a/mm/nommu.c @@ -1296,7 +1296,7 @@ unsigned long ksys_mmap_pgoff(unsigned l goto out; } - flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE); + flags &= ~MAP_DENYWRITE; retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff); _
