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| author | Sami Kerola | 2015-10-31 20:21:16 +0100 |
|---|---|---|
| committer | Karel Zak | 2015-11-09 09:56:14 +0100 |
| commit | c3a9f86fcd1977365bbbe9aaee36b02df9f330f5 (patch) | |
| tree | f30b4d178f6b06272638c36ea7322f639a6618cc /term-utils/agetty.c | |
| parent | fsck: retire stat(3) when access(3) does better job (diff) | |
| download | kernel-qcow2-util-linux-c3a9f86fcd1977365bbbe9aaee36b02df9f330f5.tar.gz kernel-qcow2-util-linux-c3a9f86fcd1977365bbbe9aaee36b02df9f330f5.tar.xz kernel-qcow2-util-linux-c3a9f86fcd1977365bbbe9aaee36b02df9f330f5.zip | |
agetty: fix chown(3), chmod(3) and open(3) race
Signed-off-by: Sami Kerola <kerolasa@iki.fi>
Diffstat (limited to 'term-utils/agetty.c')
| -rw-r--r-- | term-utils/agetty.c | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/term-utils/agetty.c b/term-utils/agetty.c index 0237b79d9..a9c878547 100644 --- a/term-utils/agetty.c +++ b/term-utils/agetty.c @@ -1004,23 +1004,23 @@ static void open_tty(char *tty, struct termios *tp, struct options *op) (int)sizeof(buf)) || (len < 0)) log_err(_("/dev/%s: cannot open as standard input: %m"), tty); + /* Open the tty as standard input. */ + if ((fd = open(buf, O_RDWR|O_NOCTTY|O_NONBLOCK, 0)) < 0) + log_err(_("/dev/%s: cannot open as standard input: %m"), tty); + /* * There is always a race between this reset and the call to * vhangup() that s.o. can use to get access to your tty. * Linux login(1) will change tty permissions. Use root owner and group * with permission -rw------- for the period between getty and login. */ - if (chown(buf, 0, gid) || chmod(buf, (gid ? 0620 : 0600))) { + if (fchown(fd, 0, gid) || fchmod(fd, (gid ? 0620 : 0600))) { if (errno == EROFS) log_warn("%s: %m", buf); else log_err("%s: %m", buf); } - /* Open the tty as standard input. */ - if ((fd = open(buf, O_RDWR|O_NOCTTY|O_NONBLOCK, 0)) < 0) - log_err(_("/dev/%s: cannot open as standard input: %m"), tty); - /* Sanity checks... */ if (fstat(fd, &st) < 0) log_err("%s: %m", buf); |