| Message ID | 1441527246-18189-1-git-send-email-agruenba@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Sun, Sep 06, 2015 at 10:14:06AM +0200, Andreas Gruenbacher wrote: > [This replaces v7 of this patch; MAY_DELETE_SELF now properly overrides the > sticky check.] > > Normally, deleting a file requires MAY_WRITE access to the parent > directory. With richacls, a file may be deleted with MAY_DELETE_CHILD access > to the parent directory or with MAY_DELETE_SELF access to the file. > > To support that, pass the MAY_DELETE_CHILD mask flag to inode_permission() > when checking for delete access inside a directory, and MAY_DELETE_SELF > when checking for delete access to a file itelf. > > The MAY_DELETE_SELF permission overrides the sticky directory check. > Reviewed-by: J. Bruce Fields <bfields@redhat.com> > Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> > --- > fs/namei.c | 21 ++++++++++++--------- > include/linux/fs.h | 2 ++ > 2 files changed, 14 insertions(+), 9 deletions(-) > > diff --git a/fs/namei.c b/fs/namei.c > index 428b4a6..1a3f0d8 100644 > --- a/fs/namei.c > +++ b/fs/namei.c > @@ -453,9 +453,9 @@ static int sb_permission(struct super_block *sb, struct inode *inode, int mask) > * this, letting us set arbitrary permissions for filesystem access without > * changing the "normal" UIDs which are used for other things. > * > - * MAY_WRITE must be set in @mask whenever MAY_APPEND, MAY_CREATE_FILE, or > - * MAY_CREATE_DIR are set. That way, file systems that don't support these > - * permissions will check for MAY_WRITE instead. > + * MAY_WRITE must be set in @mask whenever MAY_APPEND, MAY_CREATE_FILE, > + * MAY_CREATE_DIR, or MAY_DELETE_CHILD are set. That way, file systems that > + * don't support these permissions will check for MAY_WRITE instead. > */ > int inode_permission(struct inode *inode, int mask) > { > @@ -2528,7 +2528,7 @@ static int may_delete(struct inode *dir, struct dentry *victim, > bool isdir, bool replace) > { > struct inode *inode = d_backing_inode(victim); > - int error, mask = MAY_WRITE | MAY_EXEC; > + int error, mask = MAY_EXEC; > > if (d_is_negative(victim)) > return -ENOENT; > @@ -2538,15 +2538,18 @@ static int may_delete(struct inode *dir, struct dentry *victim, > audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE); > > if (replace) > - mask |= isdir ? MAY_CREATE_DIR : MAY_CREATE_FILE; > - error = inode_permission(dir, mask); > + mask |= MAY_WRITE | (isdir ? MAY_CREATE_DIR : MAY_CREATE_FILE); > + error = inode_permission(dir, mask | MAY_WRITE | MAY_DELETE_CHILD); > + if (!error && check_sticky(dir, inode)) > + error = -EPERM; > + if (error && IS_RICHACL(inode) && > + inode_permission(inode, MAY_DELETE_SELF) == 0) > + error = 0; > if (error) > return error; > if (IS_APPEND(dir)) > return -EPERM; > - > - if (check_sticky(dir, inode) || IS_APPEND(inode) || > - IS_IMMUTABLE(inode) || IS_SWAPFILE(inode)) > + if (IS_APPEND(inode) || IS_IMMUTABLE(inode) || IS_SWAPFILE(inode)) > return -EPERM; > if (isdir) { > if (!d_is_dir(victim)) > diff --git a/include/linux/fs.h b/include/linux/fs.h > index b2f1b1b..99c95d1 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -84,6 +84,8 @@ typedef void (dax_iodone_t)(struct buffer_head *bh_map, int uptodate); > #define MAY_NOT_BLOCK 0x00000080 > #define MAY_CREATE_FILE 0x00000100 > #define MAY_CREATE_DIR 0x00000200 > +#define MAY_DELETE_CHILD 0x00000400 > +#define MAY_DELETE_SELF 0x00000800 > > /* > * flags in file.f_mode. Note that FMODE_READ and FMODE_WRITE must correspond > -- > 2.4.3 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/namei.c b/fs/namei.c index 428b4a6..1a3f0d8 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -453,9 +453,9 @@ static int sb_permission(struct super_block *sb, struct inode *inode, int mask) * this, letting us set arbitrary permissions for filesystem access without * changing the "normal" UIDs which are used for other things. * - * MAY_WRITE must be set in @mask whenever MAY_APPEND, MAY_CREATE_FILE, or - * MAY_CREATE_DIR are set. That way, file systems that don't support these - * permissions will check for MAY_WRITE instead. + * MAY_WRITE must be set in @mask whenever MAY_APPEND, MAY_CREATE_FILE, + * MAY_CREATE_DIR, or MAY_DELETE_CHILD are set. That way, file systems that + * don't support these permissions will check for MAY_WRITE instead. */ int inode_permission(struct inode *inode, int mask) { @@ -2528,7 +2528,7 @@ static int may_delete(struct inode *dir, struct dentry *victim, bool isdir, bool replace) { struct inode *inode = d_backing_inode(victim); - int error, mask = MAY_WRITE | MAY_EXEC; + int error, mask = MAY_EXEC; if (d_is_negative(victim)) return -ENOENT; @@ -2538,15 +2538,18 @@ static int may_delete(struct inode *dir, struct dentry *victim, audit_inode_child(dir, victim, AUDIT_TYPE_CHILD_DELETE); if (replace) - mask |= isdir ? MAY_CREATE_DIR : MAY_CREATE_FILE; - error = inode_permission(dir, mask); + mask |= MAY_WRITE | (isdir ? MAY_CREATE_DIR : MAY_CREATE_FILE); + error = inode_permission(dir, mask | MAY_WRITE | MAY_DELETE_CHILD); + if (!error && check_sticky(dir, inode)) + error = -EPERM; + if (error && IS_RICHACL(inode) && + inode_permission(inode, MAY_DELETE_SELF) == 0) + error = 0; if (error) return error; if (IS_APPEND(dir)) return -EPERM; - - if (check_sticky(dir, inode) || IS_APPEND(inode) || - IS_IMMUTABLE(inode) || IS_SWAPFILE(inode)) + if (IS_APPEND(inode) || IS_IMMUTABLE(inode) || IS_SWAPFILE(inode)) return -EPERM; if (isdir) { if (!d_is_dir(victim)) diff --git a/include/linux/fs.h b/include/linux/fs.h index b2f1b1b..99c95d1 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -84,6 +84,8 @@ typedef void (dax_iodone_t)(struct buffer_head *bh_map, int uptodate); #define MAY_NOT_BLOCK 0x00000080 #define MAY_CREATE_FILE 0x00000100 #define MAY_CREATE_DIR 0x00000200 +#define MAY_DELETE_CHILD 0x00000400 +#define MAY_DELETE_SELF 0x00000800 /* * flags in file.f_mode. Note that FMODE_READ and FMODE_WRITE must correspond
[This replaces v7 of this patch; MAY_DELETE_SELF now properly overrides the sticky check.] Normally, deleting a file requires MAY_WRITE access to the parent directory. With richacls, a file may be deleted with MAY_DELETE_CHILD access to the parent directory or with MAY_DELETE_SELF access to the file. To support that, pass the MAY_DELETE_CHILD mask flag to inode_permission() when checking for delete access inside a directory, and MAY_DELETE_SELF when checking for delete access to a file itelf. The MAY_DELETE_SELF permission overrides the sticky directory check. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> --- fs/namei.c | 21 ++++++++++++--------- include/linux/fs.h | 2 ++ 2 files changed, 14 insertions(+), 9 deletions(-)