If the directory is corrupted and the number of nlinks is less than 2 (valid nlinks have at least 2), then when the directory is deleted, the minix_rmdir will try to reduce the nlinks(unsigned int) to a negative value.

Make nlinks validity check for directory in minix_lookup.

Signed-off-by: Andrey Kriulin kitotavrik.s@gmail.com --- v2: Move nlinks validaty check to V[12]_minix_iget() per Jan Kara jack@suse.cz request. Change return error code to EUCLEAN. Don't block directory in r/o mode per Al Viro viro@zeniv.linux.org.uk request.

fs/minix/inode.c | 16 ++++++++++++++++ fs/minix/namei.c | 7 +------ 2 files changed, 17 insertions(+), 6 deletions(-)

diff --git a/fs/minix/inode.c b/fs/minix/inode.c index f007e389d5d2..d815397b8b0d 100644 --- a/fs/minix/inode.c +++ b/fs/minix/inode.c @@ -517,6 +517,14 @@ static struct inode *V1_minix_iget(struct inode *inode) iget_failed(inode); return ERR_PTR(-ESTALE); } + if (S_ISDIR(raw_inode->i_mode) && raw_inode->i_nlinks < 2) { + printk("MINIX-fs: inode directory with corrupted number of links"); + if (!sb_rdonly(inode->i_sb)) { + brelse(bh); + iget_failed(inode); + return ERR_PTR(-EUCLEAN); + } + } inode->i_mode = raw_inode->i_mode; i_uid_write(inode, raw_inode->i_uid); i_gid_write(inode, raw_inode->i_gid); @@ -555,6 +563,14 @@ static struct inode *V2_minix_iget(struct inode *inode) iget_failed(inode); return ERR_PTR(-ESTALE); } + if (S_ISDIR(raw_inode->i_mode) && raw_inode->i_nlinks < 2) { + printk("MINIX-fs: inode directory with corrupted number of links"); + if (!sb_rdonly(inode->i_sb)) { + brelse(bh); + iget_failed(inode); + return ERR_PTR(-EUCLEAN); + } + } inode->i_mode = raw_inode->i_mode; i_uid_write(inode, raw_inode->i_uid); i_gid_write(inode, raw_inode->i_gid); diff --git a/fs/minix/namei.c b/fs/minix/namei.c index 5717a56fa01a..8938536d8d3c 100644 --- a/fs/minix/namei.c +++ b/fs/minix/namei.c @@ -28,13 +28,8 @@ static struct dentry *minix_lookup(struct inode * dir, struct dentry *dentry, un return ERR_PTR(-ENAMETOOLONG);

ino = minix_inode_by_name(dentry); - if (ino) { + if (ino) inode = minix_iget(dir->i_sb, ino); - if (S_ISDIR(inode->i_mode) && inode->i_nlink < 2) { - iput(inode); - return ERR_PTR(-EIO); - } - } return d_splice_alias(inode, dentry); }