Merge tag 'execve-v6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull execve updates from Kees Cook:

 - Support non-BSS ELF segments with zero filesz

   Eric Biederman and I refactored ELF segment loading to handle the
   case where a segment has a smaller filesz than memsz. Traditionally
   linkers only did this for .bss and it was always the last segment. As
   a result, the kernel only handled this case when it was the last
   segment. We've had two recent cases where linkers were trying to use
   these kinds of segments for other reasons, and the were in the middle
   of the segment list. There was no good reason for the kernel not to
   support this, and the refactor actually ends up making things more
   readable too.

 - Enable namespaced binfmt_misc

   Christian Brauner has made it possible to use binfmt_misc with mount
   namespaces. This means some traditionally root-only interfaces (for
   adding/removing formats) are now more exposed (but believed to be
   safe).

 - Remove struct tag 'dynamic' from ELF UAPI

   Alejandro Colomar noticed that the ELF UAPI has been polluting the
   struct namespace with an unused and overly generic tag named
   "dynamic" for no discernible reason for many many years. After
   double-checking various distro source repositories, it has been
   removed.

 - Clean up binfmt_elf_fdpic debug output (Greg Ungerer)

* tag 'execve-v6.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  binfmt_misc: enable sandboxed mounts
  binfmt_misc: cleanup on filesystem umount
  binfmt_elf_fdpic: clean up debug warnings
  mm: Remove unused vm_brk()
  binfmt_elf: Only report padzero() errors when PROT_WRITE
  binfmt_elf: Use elf_load() for library
  binfmt_elf: Use elf_load() for interpreter
  binfmt_elf: elf_bss no longer used by load_elf_binary()
  binfmt_elf: Support segments with 0 filesz and misaligned starts
  elf, uapi: Remove struct tag 'dynamic'

4 files changed, 20 insertions, 3 deletions

diff --git a/include/linux/binfmts.h b/include/linux/binfmts.h
index 8d51f69f9f5e..70f97f685bff 100644
--- a/include/linux/binfmts.h
+++ b/include/linux/binfmts.h
@@ -90,6 +90,16 @@ struct linux_binfmt {
 #endif
 } __randomize_layout;
 
+#if IS_ENABLED(CONFIG_BINFMT_MISC)
+struct binfmt_misc {
+	struct list_head entries;
+	rwlock_t entries_lock;
+	bool enabled;
+} __randomize_layout;
+
+extern struct binfmt_misc init_binfmt_misc;
+#endif
+
 extern void __register_binfmt(struct linux_binfmt *fmt, int insert);
 
 /* Registration of default binfmt handlers */
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 19fc73b02c9f..116c28c51468 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3308,8 +3308,7 @@ static inline void mm_populate(unsigned long addr, unsigned long len)
 static inline void mm_populate(unsigned long addr, unsigned long len) {}
 #endif
 
-/* These take the mm semaphore themselves */
-extern int __must_check vm_brk(unsigned long, unsigned long);
+/* This takes the mm semaphore itself */
 extern int __must_check vm_brk_flags(unsigned long, unsigned long, unsigned long);
 extern int vm_munmap(unsigned long, size_t);
 extern unsigned long __must_check vm_mmap(struct file *, unsigned long,
diff --git a/include/linux/user_namespace.h b/include/linux/user_namespace.h
index 45f09bec02c4..6030a8235617 100644
--- a/include/linux/user_namespace.h
+++ b/include/linux/user_namespace.h
@@ -65,6 +65,10 @@ enum rlimit_type {
 	UCOUNT_RLIMIT_COUNTS,
 };
 
+#if IS_ENABLED(CONFIG_BINFMT_MISC)
+struct binfmt_misc;
+#endif
+
 struct user_namespace {
 	struct uid_gid_map	uid_map;
 	struct uid_gid_map	gid_map;
@@ -102,6 +106,10 @@ struct user_namespace {
 	struct ucounts		*ucounts;
 	long ucount_max[UCOUNT_COUNTS];
 	long rlimit_max[UCOUNT_RLIMIT_COUNTS];
+
+#if IS_ENABLED(CONFIG_BINFMT_MISC)
+	struct binfmt_misc *binfmt_misc;
+#endif
 } __randomize_layout;
 
 struct ucounts {
diff --git a/include/uapi/linux/elf.h b/include/uapi/linux/elf.h
index 9b731976ce2f..9417309b7230 100644
--- a/include/uapi/linux/elf.h
+++ b/include/uapi/linux/elf.h
@@ -140,7 +140,7 @@ typedef __s64	Elf64_Sxword;
 #define ELF64_ST_BIND(x)	ELF_ST_BIND(x)
 #define ELF64_ST_TYPE(x)	ELF_ST_TYPE(x)
 
-typedef struct dynamic {
+typedef struct {
   Elf32_Sword d_tag;
   union {
     Elf32_Sword	d_val;