diff options
| author | Ard Biesheuvel <ardb@kernel.org> | 2024-02-14 13:29:28 +0100 |
|---|---|---|
| committer | Catalin Marinas <catalin.marinas@arm.com> | 2024-02-16 12:42:43 +0000 |
| commit | cb1a393c40eee2f1692c995ea0cc6e45bfccde4d (patch) | |
| tree | cdb22e3f9f77883f442ad3f1e279c5040309751f /mm/mmap.c | |
| parent | 5d101654226d64ac0a6928019fbf476b46e9d14b (diff) | |
mm: add arch hook to validate mmap() prot flags
Add a hook to permit architectures to perform validation on the prot
flags passed to mmap(), like arch_validate_prot() does for mprotect().
This will be used by arm64 to reject PROT_WRITE+PROT_EXEC mappings on
configurations that run with WXN enabled.
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20240214122845.2033971-87-ardb+git@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Diffstat (limited to 'mm/mmap.c')
| -rw-r--r-- | mm/mmap.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/mm/mmap.c b/mm/mmap.c index d89770eaab6b..977a8c3fd9f5 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1229,6 +1229,9 @@ unsigned long do_mmap(struct file *file, unsigned long addr, if (!(file && path_noexec(&file->f_path))) prot |= PROT_EXEC; + if (!arch_validate_mmap_prot(prot, addr)) + return -EACCES; + /* force arch specific MAP_FIXED handling in get_unmapped_area */ if (flags & MAP_FIXED_NOREPLACE) flags |= MAP_FIXED; |