mcp2@csd4.milw.wisc.edu (Michael C Polinske) (03/04/89)
Last night while working on the system I discovered a very serious bug in the screen program: The system was very busy, and I was working away trying to get my program done. I gave the command to open up another window "C-a c." After about 15 seconds the window opened. But some thing was different. I didn't have my normal prompt, I had what appeared to be someone else's. I did a pwd and it showed that I was in another person's directory. I did a whoami and it showed that I was the person whose directory I was in. So, I issued the login command. The command executed fine, but because I have my .login set up so that I go right into screen, it set up another set of screens. but the commands would only work in the first set. I next killed all of the current screens that I could, logged out of the main tty that I was on and logged in again. I checked what processes I had running and found theat the jobs on the pty where I did a login were still running. So i killed those and yet I was still taking up that pty. In tcsh it is supposed to automatically log you out, well according to the `w' command I am still logged in there doing nothing and a idle time of about 24 hours. So I guess I'll be taking up that port until the system goes down. What apparently happened was because ttys were rare with the high number of users, and the person who had just been on that pty just turned of the terminal instead of logging out and I just happened to go into that pty before the computer had a chance to completely close the previous connection. I hope that in the next release of screen the author(who?) includes a routine that will double check that the pty is closed before opening it up to set up another window. -- |snail mail: Michael Charles Polinske |email: mcp2@csd4.milw.wisc.edu | | 5730 North 68th St. | | | Milwaukee, WI 53218 |Telephone: 1+(414) 461-3717 |
net@tub.UUCP (Oliver Laumann) (03/05/89)
In article <MCP2.89Mar3163135@csd4.milw.wisc.edu> mcp2@csd4.milw.wisc.edu (Michael C Polinske) writes: > Last night while working on the system I discovered a very serious bug > in the screen program: [opening a window gets connected to another person's login session] This is a bug in the pseudo-tty implementation rather than a bug in screen. It should not be possible to allocate a pty that has not been closed. Regards, -- Oliver Laumann net@TUB.BITNET net@tub.UUCP