Posix-timers armed with a short interval with an ignored signal result
in an unpriviledged DoS. Due to the ignored signal the timer switches
into self rearm mode. This issue had been "fixed" before but a rework of
the alarmtimer code 5 years ago lost that workaround.
There is no real good solution for this issue, which is also worked around
in the core posix-timer code in the same way, but it certainly moved way
up on the ever growing todo list.
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Merge tag 'timers-urgent-2023-02-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Thomas Gleixner:
"A fix for a long standing issue in the alarmtimer code.
Posix-timers armed with a short interval with an ignored signal result
in an unpriviledged DoS. Due to the ignored signal the timer switches
into self rearm mode. This issue had been "fixed" before but a rework
of the alarmtimer code 5 years ago lost that workaround.
There is no real good solution for this issue, which is also worked
around in the core posix-timer code in the same way, but it certainly
moved way up on the ever growing todo list"
* tag 'timers-urgent-2023-02-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
alarmtimer: Prevent starvation by small intervals and SIG_IGN
0097c18e45