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authorAl Viro <viro@zeniv.linux.org.uk>2014-12-02 15:59:37 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-12-03 09:36:03 -0800
commit1ead0e79bfedd4b563b8ea7c585ca3884b0c89a7 (patch)
tree7ef8e695dea004a6c6d8b8f2b602140b2912a014
parente8577d1f0329d4842e8302e289fb2c22156abef4 (diff)
downloadlinux-linaro-stable-1ead0e79bfedd4b563b8ea7c585ca3884b0c89a7.tar.gz
fat: fix oops on corrupted vfat fs
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) [hirofumi@mail.parknet.co.jp: make change minimum, don't call d_move() for dir] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: <stable@vger.kernel.org> [3.17.x] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--fs/fat/namei_vfat.c20
1 files changed, 11 insertions, 9 deletions
diff --git a/fs/fat/namei_vfat.c b/fs/fat/namei_vfat.c
index 6df8d3d885e5..b8b92c2f9683 100644
--- a/fs/fat/namei_vfat.c
+++ b/fs/fat/namei_vfat.c
@@ -736,7 +736,12 @@ static struct dentry *vfat_lookup(struct inode *dir, struct dentry *dentry,
}
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 inode *dir, struct dentry *dentry,
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, struct dentry *dentry, umode_t mode,
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, struct dentry *dentry)
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, struct dentry *dentry)
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, struct dentry *dentry, umode_t mode)
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);