Patch "binfmt_misc: fix shift-out-of-bounds in check_special_flags" has been added to the 4.19-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    binfmt_misc: fix shift-out-of-bounds in check_special_flags

to the 4.19-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     binfmt_misc-fix-shift-out-of-bounds-in-check_special.patch
and it can be found in the queue-4.19 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit a422917e30ed4f5eebc929450c9b77c73139a612
Author: Liu Shixin <liushixin2@xxxxxxxxxx>
Date:   Wed Nov 2 10:51:23 2022 +0800

    binfmt_misc: fix shift-out-of-bounds in check_special_flags
    
    [ Upstream commit 6a46bf558803dd2b959ca7435a5c143efe837217 ]
    
    UBSAN reported a shift-out-of-bounds warning:
    
     left shift of 1 by 31 places cannot be represented in type 'int'
     Call Trace:
      <TASK>
      __dump_stack lib/dump_stack.c:88 [inline]
      dump_stack_lvl+0x8d/0xcf lib/dump_stack.c:106
      ubsan_epilogue+0xa/0x44 lib/ubsan.c:151
      __ubsan_handle_shift_out_of_bounds+0x1e7/0x208 lib/ubsan.c:322
      check_special_flags fs/binfmt_misc.c:241 [inline]
      create_entry fs/binfmt_misc.c:456 [inline]
      bm_register_write+0x9d3/0xa20 fs/binfmt_misc.c:654
      vfs_write+0x11e/0x580 fs/read_write.c:582
      ksys_write+0xcf/0x120 fs/read_write.c:637
      do_syscall_x64 arch/x86/entry/common.c:50 [inline]
      do_syscall_64+0x34/0x80 arch/x86/entry/common.c:80
      entry_SYSCALL_64_after_hwframe+0x63/0xcd
     RIP: 0033:0x4194e1
    
    Since the type of Node's flags is unsigned long, we should define these
    macros with same type too.
    
    Signed-off-by: Liu Shixin <liushixin2@xxxxxxxxxx>
    Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
    Link: https://lore.kernel.org/r/20221102025123.1117184-1-liushixin2@xxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/fs/binfmt_misc.c b/fs/binfmt_misc.c
index 27a04f492541..8fe7edd2b001 100644
--- a/fs/binfmt_misc.c
+++ b/fs/binfmt_misc.c
@@ -42,10 +42,10 @@ static LIST_HEAD(entries);
 static int enabled = 1;
 
 enum {Enabled, Magic};
-#define MISC_FMT_PRESERVE_ARGV0 (1 << 31)
-#define MISC_FMT_OPEN_BINARY (1 << 30)
-#define MISC_FMT_CREDENTIALS (1 << 29)
-#define MISC_FMT_OPEN_FILE (1 << 28)
+#define MISC_FMT_PRESERVE_ARGV0 (1UL << 31)
+#define MISC_FMT_OPEN_BINARY (1UL << 30)
+#define MISC_FMT_CREDENTIALS (1UL << 29)
+#define MISC_FMT_OPEN_FILE (1UL << 28)
 
 typedef struct {
 	struct list_head list;