From: David Hildenbrand <david@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: "David Hildenbrand" <david@redhat.com>,
"Linus Torvalds" <torvalds@linux-foundation.org>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Thomas Gleixner" <tglx@linutronix.de>,
"Ingo Molnar" <mingo@redhat.com>,
"Borislav Petkov" <bp@alien8.de>,
"H. Peter Anvin" <hpa@zytor.com>,
"Alexander Viro" <viro@zeniv.linux.org.uk>,
"Alexey Dobriyan" <adobriyan@gmail.com>,
"Steven Rostedt" <rostedt@goodmis.org>,
"Peter Zijlstra" <peterz@infradead.org>,
"Arnaldo Carvalho de Melo" <acme@kernel.org>,
"Mark Rutland" <mark.rutland@arm.com>,
"Alexander Shishkin" <alexander.shishkin@linux.intel.com>,
"Jiri Olsa" <jolsa@redhat.com>,
"Namhyung Kim" <namhyung@kernel.org>,
"Petr Mladek" <pmladek@suse.com>,
"Sergey Senozhatsky" <sergey.senozhatsky@gmail.com>,
"Andy Shevchenko" <andriy.shevchenko@linux.intel.com>,
"Rasmus Villemoes" <linux@rasmusvillemoes.dk>,
"Kees Cook" <keescook@chromium.org>,
"Eric W. Biederman" <ebiederm@xmission.com>,
"Greg Ungerer" <gerg@linux-m68k.org>,
"Geert Uytterhoeven" <geert@linux-m68k.org>,
"Mike Rapoport" <rppt@kernel.org>,
"Vlastimil Babka" <vbabka@suse.cz>,
"Vincenzo Frascino" <vincenzo.frascino@arm.com>,
"Chinwen Chang" <chinwen.chang@mediatek.com>,
"Catalin Marinas" <catalin.marinas@arm.com>,
"Matthew Wilcox (Oracle)" <willy@infradead.org>,
"Huang Ying" <ying.huang@intel.com>,
"Jann Horn" <jannh@google.com>, "Feng Tang" <feng.tang@intel.com>,
"Kevin Brodsky" <Kevin.Brodsky@arm.com>,
"Michael Ellerman" <mpe@ellerman.id.au>,
"Shawn Anastasio" <shawn@anastas.io>,
"Steven Price" <steven.price@arm.com>,
"Nicholas Piggin" <npiggin@gmail.com>,
"Christian Brauner" <christian.brauner@ubuntu.com>,
"Jens Axboe" <axboe@kernel.dk>,
"Gabriel Krisman Bertazi" <krisman@collabora.com>,
"Peter Xu" <peterx@redhat.com>,
"Suren Baghdasaryan" <surenb@google.com>,
"Shakeel Butt" <shakeelb@google.com>,
"Marco Elver" <elver@google.com>,
"Daniel Jordan" <daniel.m.jordan@oracle.com>,
"Nicolas Viennot" <Nicolas.Viennot@twosigma.com>,
"Thomas Cedeno" <thomascedeno@google.com>,
"Michal Hocko" <mhocko@suse.com>,
"Miklos Szeredi" <miklos@szeredi.hu>,
"Chengguang Xu" <cgxu519@mykernel.net>,
"Christian König" <ckoenig.leichtzumerken@gmail.com>,
"Florian Weimer" <fweimer@redhat.com>,
"David Laight" <David.Laight@ACULAB.COM>,
linux-unionfs@vger.kernel.org, linux-api@vger.kernel.org,
x86@kernel.org, linux-fsdevel@vger.kernel.org,
linux-mm@kvack.org
Subject: [PATCH v2 6/7] mm: ignore MAP_DENYWRITE in ksys_mmap_pgoff()
Date: Mon, 16 Aug 2021 21:48:39 +0200 [thread overview]
Message-ID: <20210816194840.42769-7-david@redhat.com> (raw)
In-Reply-To: <20210816194840.42769-1-david@redhat.com>
Let's also remove masking off MAP_DENYWRITE from ksys_mmap_pgoff():
the last in-tree occurrence of MAP_DENYWRITE 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_DENYWRITE is ignored.
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
include/linux/mman.h | 3 ++-
mm/mmap.c | 2 --
mm/nommu.c | 2 --
3 files changed, 2 insertions(+), 5 deletions(-)
diff --git a/include/linux/mman.h b/include/linux/mman.h
index bd9aadda047b..b66e91b8176c 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -32,7 +32,8 @@
* 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.
+ * MAP_EXECUTABLE and MAP_DENYWRITE are completely ignored throughout the
+ * kernel.
*/
#define LEGACY_MAP_MASK (MAP_SHARED \
| MAP_PRIVATE \
diff --git a/mm/mmap.c b/mm/mmap.c
index 589dc1dc13db..bf11fc6e8311 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -1626,8 +1626,6 @@ unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len,
return PTR_ERR(file);
}
- flags &= ~MAP_DENYWRITE;
-
retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff);
out_fput:
if (file)
diff --git a/mm/nommu.c b/mm/nommu.c
index 3a93d4054810..0987d131bdfc 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -1296,8 +1296,6 @@ unsigned long ksys_mmap_pgoff(unsigned long addr, unsigned long len,
goto out;
}
- flags &= ~MAP_DENYWRITE;
-
retval = vm_mmap_pgoff(file, addr, len, prot, flags, pgoff);
if (file)
--
2.31.1
next prev parent reply other threads:[~2021-08-16 19:51 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-08-16 19:48 [PATCH v2 0/7] Remove in-tree usage of MAP_DENYWRITE David Hildenbrand
2021-08-16 19:48 ` [PATCH v2 1/7] binfmt: don't use MAP_DENYWRITE when loading shared libraries via uselib() David Hildenbrand
2021-09-05 15:32 ` Guenter Roeck
2021-09-05 17:17 ` Linus Torvalds
2021-09-05 19:07 ` David Hildenbrand
2021-08-16 19:48 ` [PATCH v2 2/7] kernel/fork: factor out replacing the current MM exe_file David Hildenbrand
2021-08-19 20:51 ` Linus Torvalds
2021-08-20 8:46 ` David Hildenbrand
2021-08-20 14:36 ` Eric W. Biederman
2021-08-22 17:58 ` Linus Torvalds
2021-08-16 19:48 ` [PATCH v2 3/7] kernel/fork: always deny write access to " David Hildenbrand
2021-08-16 19:48 ` [PATCH v2 4/7] binfmt: remove in-tree usage of MAP_DENYWRITE David Hildenbrand
2021-08-16 19:48 ` [PATCH v2 5/7] mm: remove VM_DENYWRITE David Hildenbrand
2021-08-16 19:48 ` David Hildenbrand [this message]
2021-08-16 19:48 ` [PATCH v2 7/7] fs: update documentation of get_write_access() and friends David Hildenbrand
2021-08-17 11:01 ` [PATCH v2 0/7] Remove in-tree usage of MAP_DENYWRITE Christian König
2021-09-03 9:45 ` David Hildenbrand
2021-09-03 16:26 ` Linus Torvalds
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