Differences between version 6 and previous revision of RaceCondition.
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| Newer page: | version 6 | Last edited on Monday, October 18, 2004 5:14:30 am | by AristotlePagaltzis | Revert |
| Older page: | version 5 | Last edited on Monday, October 18, 2004 5:11:47 am | by AristotlePagaltzis | Revert |
@@ -1,5 +1,5 @@
A RaceCondition is a [Synchronisation] bug in which the results of some computation or action depend in an unsafe way upon the the actions of other threads or processes. RaceCondition~s are a particularly challenging when writing InterruptHandler~s in the [Kernel] or SignalHandler~s in applications.
-Several
security-related RaceCondition~s have occurred when a program checks
file permissions and ownership before reading the
file. The obvious implementation of this has
a RaceCondition which allows the
file to
be changed between the check and the reading
. File operations should if at all possible be [Atomic].
+Many
security-related RaceCondition~s have been found where programs would check
file properties (such as existence,
permissions,
and/or
ownership)
before operating on a
file. The obvious implementation of this is
a RaceCondition, because these
file properties can
be changed between the check and operation
. File operations should if at all possible be [Atomic].
A DeadLock is perfered to a RaceCondition, because with a DeadLock, something is obviously wrong, whereas a RaceCondition can give no indication of a problem until someone notices corrupt data or a security breach.
