@@ -489,7 +489,8 @@ SYSCALL_DEFINE1(chroot, const char __user *, filename)
if (error)
goto out;
- error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR);
+ error = inode_permission(path.dentry->d_inode, MAY_EXEC | MAY_CHDIR |
+ MAY_CHROOT);
if (error)
goto dput_and_out;
@@ -90,6 +90,7 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset,
#define MAY_CHDIR 0x00000040
/* called from RCU mode, don't block */
#define MAY_NOT_BLOCK 0x00000080
+#define MAY_CHROOT 0x00000100
/*
* flags in file.f_mode. Note that FMODE_READ and FMODE_WRITE must correspond
For compatibility reason, MAY_CHROOT is always set with MAY_CHDIR. However, this new flag enable to differentiate a chdir form a chroot. This is needed for the Landlock LSM to be able to evaluate a new root directory. Signed-off-by: Mickaël Salaün <mic@digikod.net> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Casey Schaufler <casey@schaufler-ca.com> Cc: James Morris <jmorris@namei.org> Cc: John Johansen <john.johansen@canonical.com> Cc: Kees Cook <keescook@chromium.org> Cc: Paul Moore <paul@paul-moore.com> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Cc: linux-fsdevel@vger.kernel.org --- fs/open.c | 3 ++- include/linux/fs.h | 1 + 2 files changed, 3 insertions(+), 1 deletion(-)