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| author | Al Viro <viro@zeniv.linux.org.uk> | 2014-12-02 15:59:37 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-12-03 09:36:03 -0800 |
| commit | 1ead0e79bfedd4b563b8ea7c585ca3884b0c89a7 (patch) | |
| tree | 7ef8e695dea004a6c6d8b8f2b602140b2912a014 /fs/fat | |
| parent | e8577d1f0329d4842e8302e289fb2c22156abef4 (diff) | |
| download | linux-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>
Diffstat (limited to 'fs/fat')
| -rw-r--r-- | fs/fat/namei_vfat.c | 20 |
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); |