From: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
To: Andrew Morton <akpm@linux-foundation.org>
Cc: viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org,
linux-fsdevel@vger.kernel.org
Subject: [PATCH] fat: Fix oops on corrupted vfat fs
Date: Thu, 27 Nov 2014 00:31:28 +0900 [thread overview]
Message-ID: <873896x9kf.fsf@devron.myhome.or.jp> (raw)
a) don't bother with ->d_time for positives - we only check it for negatives
anyway.
b) make sure to set it at unlink and rmdir time - at *that* point soon-to-be
negative dentry matches then-current directory contents
c) don't go into renaming of old alias in vfat_lookup() unless it has
the same parent (which it will, unless we are seeing corrupted image)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org> # 3.17.x
[Make change minimum, don't call d_move() for dir]
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
---
fs/fat/namei_vfat.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)
diff -puN fs/fat/namei_vfat.c~fat-corrupt-fs-fix fs/fat/namei_vfat.c
--- linux/fs/fat/namei_vfat.c~fat-corrupt-fs-fix 2014-11-10 01:09:08.782815944 +0900
+++ linux-hirofumi/fs/fat/namei_vfat.c 2014-11-10 01:56:47.283117983 +0900
@@ -736,7 +736,12 @@ static struct dentry *vfat_lookup(struct
}
alias = d_find_alias(inode);
- if (alias && !vfat_d_anon_disconn(alias)) {
+ /*
+ * Checking "alias->d_parent == dentry->d_parent" to make sure
+ * FS is not corrupted (especially double linked dir).
+ */
+ if (alias && alias->d_parent == dentry->d_parent &&
+ !vfat_d_anon_disconn(alias)) {
/*
* This inode has non anonymous-DCACHE_DISCONNECTED
* dentry. This means, the user did ->lookup() by an
@@ -755,12 +760,9 @@ static struct dentry *vfat_lookup(struct
out:
mutex_unlock(&MSDOS_SB(sb)->s_lock);
- dentry->d_time = dentry->d_parent->d_inode->i_version;
- dentry = d_splice_alias(inode, dentry);
- if (dentry)
- dentry->d_time = dentry->d_parent->d_inode->i_version;
- return dentry;
-
+ if (!inode)
+ dentry->d_time = dir->i_version;
+ return d_splice_alias(inode, dentry);
error:
mutex_unlock(&MSDOS_SB(sb)->s_lock);
return ERR_PTR(err);
@@ -793,7 +795,6 @@ static int vfat_create(struct inode *dir
inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
/* timestamp is already written, so mark_inode_dirty() is unneeded. */
- dentry->d_time = dentry->d_parent->d_inode->i_version;
d_instantiate(dentry, inode);
out:
mutex_unlock(&MSDOS_SB(sb)->s_lock);
@@ -824,6 +825,7 @@ static int vfat_rmdir(struct inode *dir,
clear_nlink(inode);
inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
fat_detach(inode);
+ dentry->d_time = dir->i_version;
out:
mutex_unlock(&MSDOS_SB(sb)->s_lock);
@@ -849,6 +851,7 @@ static int vfat_unlink(struct inode *dir
clear_nlink(inode);
inode->i_mtime = inode->i_atime = CURRENT_TIME_SEC;
fat_detach(inode);
+ dentry->d_time = dir->i_version;
out:
mutex_unlock(&MSDOS_SB(sb)->s_lock);
@@ -889,7 +892,6 @@ static int vfat_mkdir(struct inode *dir,
inode->i_mtime = inode->i_atime = inode->i_ctime = ts;
/* timestamp is already written, so mark_inode_dirty() is unneeded. */
- dentry->d_time = dentry->d_parent->d_inode->i_version;
d_instantiate(dentry, inode);
mutex_unlock(&MSDOS_SB(sb)->s_lock);
_
next reply other threads:[~2014-11-26 15:31 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-26 15:31 OGAWA Hirofumi [this message]
2014-11-26 22:28 ` [PATCH] fat: Fix oops on corrupted vfat fs Andrew Morton
2014-11-27 7:00 ` OGAWA Hirofumi
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=873896x9kf.fsf@devron.myhome.or.jp \
--to=hirofumi@mail.parknet.co.jp \
--cc=akpm@linux-foundation.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=viro@zeniv.linux.org.uk \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).