On 02/20/2013 02:19 PM, Karel Zak wrote: > On Tue, Jan 15, 2013 at 11:26:22PM +0100, Jiri Slaby wrote: >> Now that login from util-linux is forced to drop all references to a >> TTY which it wants to hangup (to reach reference count 1) we are >> seeing issues with telnet. When login closes its last reference to the >> slave PTY, it also resets packet mode on the *master* side. And we >> have a race here. > > [...] > >> By this I am resurrecting an old bug, see References. We are hitting >> it regularly now, i.e. with updated util-linux, ergo login. >> >> Here, I am changing a behavior introduced back in 2.1 times. It would >> better have a long time testing before goes upstream. > > It would be nice to found a quick way how to resolve this problem, > because telnet+login is broken now... and for end users it seems like > a regression.
Oh, the patch is in the TTY tree and I suppose it will go to 3.9-rc1 (and to stable as we will get to same later -rc -- to have some testing). > Maybe the requirement (patch) to close all references to TTY before > hangup should reverted or we can make an exception in login(1) code to > keep TTY open when login(1) is executed with -h (as used by telned). If we reverted the patch in login, we would have to revert also a patch in the TTY which closes a window allowing you to crash a kernel at will (in fact that patch disallows multiple opens when hanging up a terminal. IOW only the one to hang the terminal is allowed to have it opened.) -- js suse labs -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
