Bug#243954: Processed: Reopen and Reassign 243954

[GOTO Masanori <gotom@debian.or.jp>]

severity 243954 normal
thanks

> So if a user runs such code (or just runs a buggy program that blocks a
> signal and then receives 1000 such signals - which happens here), this
> will cause a DoS againt anything running on the same system that uses
> linuxthreads, including daemons running as root.
> 
> On systems that use NPTL (such as Linux 2.6 kernel) there is no 'thread
> zombie' problem, because in NPTL another notification mechanism is used.

Because kernel can't handle POSIX Threads appropriately for a long
time (over 5 years) before appearing NPTL.  So linuxthreads tried to
use signal because of kernel incapability.  This is a long time
problem item, and this is one reason why NPTL (for both kernel and
glibc) is written.  Use NPTL.  This bug will not be fixed.  If this
bug is focued with linuxthreads (not kernel), I just tag as "wontfix".

> However, DoS is still possible (and really happens - in form of daemon
> crashes), because when it is not possible to allocatre a "struct
> sigqueue"
> object, kernel behaviour in signal-passing changes, causing random hangs
> and segfaults in different programs.

This is not glibc, but kernel issue.

Regards,
-- gotom