| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.18 157/158] autofs: fix autofs_sbi() does not check super block type | Date | Tue, 18 Sep 2018 00:43:07 +0200 |
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4.18-stable review patch. If anyone has any objections, please let me know.
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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.
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> Cc: Guenter Roeck <groeck@google.com> Cc: Zubin Mithra <zsm@chromium.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/autofs/autofs_i.h | 4 +++- fs/autofs/inode.c | 1 - 2 files changed, 3 insertions(+), 2 deletions(-)
--- a/fs/autofs/autofs_i.h +++ b/fs/autofs/autofs_i.h @@ -26,6 +26,7 @@ #include <linux/list.h> #include <linux/completion.h> #include <linux/file.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 *autofs_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 *autofs_dentry_ino(struct dentry *dentry) --- a/fs/autofs/inode.c +++ b/fs/autofs/inode.c @@ -10,7 +10,6 @@ #include <linux/seq_file.h> #include <linux/pagemap.h> #include <linux/parser.h> -#include <linux/magic.h> #include "autofs_i.h"
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