Date: Thu, 22 Sep 2016 23:22:53 +0000 (UTC) From: Mark Johnston <markj@FreeBSD.org> To: src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: svn commit: r306220 - head/sys/cddl/dev/systrace Message-ID: <201609222322.u8MNMrxG046367@repo.freebsd.org>
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Author: markj Date: Thu Sep 22 23:22:53 2016 New Revision: 306220 URL: https://svnweb.freebsd.org/changeset/base/306220 Log: Re-check the systrace probe ID before calling dtrace_probe(). Otherwise there exists a narrow window during which a syscall probe can be disabled and cause a concurrently-running thread to call dtrace_probe() with an invalid probe ID. Reported by: ngie MFC after: 1 week Sponsored by: Dell EMC Isilon Modified: head/sys/cddl/dev/systrace/systrace.c Modified: head/sys/cddl/dev/systrace/systrace.c ============================================================================== --- head/sys/cddl/dev/systrace/systrace.c Thu Sep 22 22:51:11 2016 (r306219) +++ head/sys/cddl/dev/systrace/systrace.c Thu Sep 22 23:22:53 2016 (r306220) @@ -193,7 +193,8 @@ systrace_probe(struct syscall_args *sa, memset(uargs, 0, sizeof(uargs)); if (type == SYSTRACE_ENTRY) { - id = sa->callp->sy_entry; + if ((id = sa->callp->sy_entry) == DTRACE_IDNONE) + return; if (sa->callp->sy_systrace_args_func != NULL) /* @@ -215,7 +216,8 @@ systrace_probe(struct syscall_args *sa, */ curthread->t_dtrace_systrace_args = uargs; } else { - id = sa->callp->sy_return; + if ((id = sa->callp->sy_return) == DTRACE_IDNONE) + return; curthread->t_dtrace_systrace_args = NULL; /* Set arg0 and arg1 as the return value of this syscall. */
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