Further shmctl() SHM_LOCK strangeness

From: Michael Kerrisk
Date: Wed Nov 24 2004 - 15:21:58 EST


Manfred, Hugh,

While studying the RLIMIT_MEMLOCK stuff further, I came
up with another observation: a process can perform a
shmctl(SHM_LOCK) on *any* System V shared memory segment,
regardles of the segment's ownership or permissions,
providing the size of the segment falls within the
process's RLIMIT_MEMLOCK limit.

Is this intended behaviour? For most other System V IPC
"ctl" operations the process must either:

1. be the owner of the object or have an appropriate
capability, or

2. have suitable permissions on the object.

Which of these two conditions applies depends on the
"ctl" operation.

Cheers,

Michael

--
NEU +++ DSL Komplett von GMX +++ http://www.gmx.net/de/go/dsl
GMX DSL-Netzanschluss + Tarif zum supergünstigen Komplett-Preis!
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/