| From 0633da48f0793aeba27f82d30605624416723a91 Mon Sep 17 00:00:00 2001 |
| From: Ian Kent <raven@themaw.net> |
| Date: Tue, 21 Aug 2018 21:51:45 -0700 |
| Subject: autofs: fix autofs_sbi() does not check super block type |
| |
| From: Ian Kent <raven@themaw.net> |
| |
| commit 0633da48f0793aeba27f82d30605624416723a91 upstream. |
| |
| autofs_sbi() does not check the superblock magic number to verify it has |
| been given an autofs super block. |
| |
| Backport Note: autofs4 has been renamed to autofs upstream. As a result |
| the upstream patch does not apply cleanly onto 4.14.y. |
| |
| Link: http://lkml.kernel.org/r/153475422934.17131.7563724552005298277.stgit@pluto.themaw.net |
| Reported-by: <syzbot+87c3c541582e56943277@syzkaller.appspotmail.com> |
| Signed-off-by: Ian Kent <raven@themaw.net> |
| Reviewed-by: Andrew Morton <akpm@linux-foundation.org> |
| Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
| Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> |
| Signed-off-by: Zubin Mithra <zsm@chromium.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| fs/autofs4/autofs_i.h | 4 +++- |
| fs/autofs4/inode.c | 1 - |
| 2 files changed, 3 insertions(+), 2 deletions(-) |
| |
| --- a/fs/autofs4/autofs_i.h |
| +++ b/fs/autofs4/autofs_i.h |
| @@ -26,6 +26,7 @@ |
| #include <linux/list.h> |
| #include <linux/completion.h> |
| #include <asm/current.h> |
| +#include <linux/magic.h> |
| |
| /* This is the range of ioctl() numbers we claim as ours */ |
| #define AUTOFS_IOC_FIRST AUTOFS_IOC_READY |
| @@ -124,7 +125,8 @@ struct autofs_sb_info { |
| |
| static inline struct autofs_sb_info *autofs4_sbi(struct super_block *sb) |
| { |
| - return (struct autofs_sb_info *)(sb->s_fs_info); |
| + return sb->s_magic != AUTOFS_SUPER_MAGIC ? |
| + NULL : (struct autofs_sb_info *)(sb->s_fs_info); |
| } |
| |
| static inline struct autofs_info *autofs4_dentry_ino(struct dentry *dentry) |
| --- a/fs/autofs4/inode.c |
| +++ b/fs/autofs4/inode.c |
| @@ -14,7 +14,6 @@ |
| #include <linux/pagemap.h> |
| #include <linux/parser.h> |
| #include <linux/bitops.h> |
| -#include <linux/magic.h> |
| #include "autofs_i.h" |
| #include <linux/module.h> |
| |
