| commit | 15e9a4f378c8607c2ae1aa465436af4321db0e23 | |
| author | Christian Brauner <christian.brauner@canonical.com> | |
| Fri, 27 Jan 2017 14:59:59 +0000 (27 15:59 +0100) | ||
| committer | Dmitry V. Levin <ldv@altlinux.org> | |
| Sun, 19 Mar 2017 17:36:13 +0000 (19 17:36 +0000) | ||
| tree | 021ac3c62fe588a8745fcdf09d29392a837759e0 | treesnapshot (tar.gz zip) |
| parent | 345118d7f5bc42c8d4c3a8ef70b9b709fa57e93d | commitdiff |
linux ttyname and ttyname_r: do not return wrong results
If a link (say /proc/self/fd/0) pointing to a device, say /dev/pts/2, in a
parent mount namespace is passed to ttyname, and a /dev/pts/2 exists (in a
different devpts) in the current namespace, then it returns /dev/pts/2.
But /dev/pts/2 is NOT the current tty, it is a different file and device.
Detect this case and return ENODEV. Userspace can choose to take this as a hint
that the fd points to a tty device but to act on the fd rather than the link.
Signed-off-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
If a link (say /proc/self/fd/0) pointing to a device, say /dev/pts/2, in a
parent mount namespace is passed to ttyname, and a /dev/pts/2 exists (in a
different devpts) in the current namespace, then it returns /dev/pts/2.
But /dev/pts/2 is NOT the current tty, it is a different file and device.
Detect this case and return ENODEV. Userspace can choose to take this as a hint
that the fd points to a tty device but to act on the fd rather than the link.
Signed-off-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>