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| author | Christian Brauner <christian.brauner@canonical.com> | 2017-01-27 15:59:59 +0100 |
|---|---|---|
| committer | Dmitry V. Levin <ldv@altlinux.org> | 2017-03-19 17:36:13 +0000 |
| commit | 15e9a4f378c8607c2ae1aa465436af4321db0e23 (patch) | |
| tree | 021ac3c62fe588a8745fcdf09d29392a837759e0 /sysdeps/unix/sysv/linux/ttyname_r.c | |
| parent | 345118d7f5bc42c8d4c3a8ef70b9b709fa57e93d (diff) | |
| download | glibc-15e9a4f378c8607c2ae1aa465436af4321db0e23.tar.gz glibc-15e9a4f378c8607c2ae1aa465436af4321db0e23.tar.xz glibc-15e9a4f378c8607c2ae1aa465436af4321db0e23.zip | |
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>
Diffstat (limited to 'sysdeps/unix/sysv/linux/ttyname_r.c')
| -rw-r--r-- | sysdeps/unix/sysv/linux/ttyname_r.c | 17 |
1 files changed, 13 insertions, 4 deletions
diff --git a/sysdeps/unix/sysv/linux/ttyname_r.c b/sysdeps/unix/sysv/linux/ttyname_r.c index 10b170a8b5..dc863526ba 100644 --- a/sysdeps/unix/sysv/linux/ttyname_r.c +++ b/sysdeps/unix/sysv/linux/ttyname_r.c @@ -28,6 +28,8 @@ #include <_itoa.h> +#include "ttyname.h" + static int getttyname_r (char *buf, size_t buflen, dev_t mydev, ino64_t myino, int save, int *dostat) internal_function; @@ -152,12 +154,19 @@ __ttyname_r (int fd, char *buf, size_t buflen) #ifdef _STATBUF_ST_RDEV && S_ISCHR (st1.st_mode) && st1.st_rdev == st.st_rdev -#else - && st1.st_ino == st.st_ino - && st1.st_dev == st.st_dev #endif - ) + && st1.st_ino == st.st_ino + && st1.st_dev == st.st_dev) return 0; + + /* If the link doesn't exist, then it points to a device in another + * namespace. + */ + if (is_pty (&st)) + { + __set_errno (ENODEV); + return ENODEV; + } } /* Prepare the result buffer. */ |