From 30710f108d29a61635778e82f300781a097caec4 Mon Sep 17 00:00:00 2001
From: Gordon Tetlow <gordon@FreeBSD.org>
Date: Tue, 1 Dec 2020 19:34:45 +0000
Subject: [PATCH] Fix execve/fexecve system call auditing.

Approved by:	so
Security:	FreeBSD-EN-20:19.audit
---
 sys/amd64/linux/linux_machdep.c       |  3 +++
 sys/amd64/linux32/linux32_machdep.c   |  3 +++
 sys/arm64/linux/linux_machdep.c       |  3 +++
 sys/compat/freebsd32/freebsd32_misc.c |  2 ++
 sys/i386/linux/linux_machdep.c        |  3 +++
 sys/kern/kern_exec.c                  |  3 +++
 sys/kern/subr_syscall.c               | 10 ++++++++++
 7 files changed, 27 insertions(+)

diff --git a/sys/amd64/linux/linux_machdep.c b/sys/amd64/linux/linux_machdep.c
index 62c676f0b8d..774fab9bc69 100644
--- a/sys/amd64/linux/linux_machdep.c
+++ b/sys/amd64/linux/linux_machdep.c
@@ -81,6 +81,8 @@ __FBSDID("$FreeBSD$");
 #include <x86/ifunc.h>
 #include <x86/sysarch.h>
 
+#include <security/audit/audit.h>
+
 #include <amd64/linux/linux.h>
 #include <amd64/linux/linux_proto.h>
 #include <compat/linux/linux_emul.h>
@@ -107,6 +109,7 @@ linux_execve(struct thread *td, struct linux_execve_args *args)
 	free(path, M_TEMP);
 	if (error == 0)
 		error = linux_common_execve(td, &eargs);
+	AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td);
 	return (error);
 }
 
diff --git a/sys/amd64/linux32/linux32_machdep.c b/sys/amd64/linux32/linux32_machdep.c
index c853f6807a6..42d9146c6df 100644
--- a/sys/amd64/linux32/linux32_machdep.c
+++ b/sys/amd64/linux32/linux32_machdep.c
@@ -69,6 +69,8 @@ __FBSDID("$FreeBSD$");
 #include <vm/vm.h>
 #include <vm/vm_map.h>
 
+#include <security/audit/audit.h>
+
 #include <compat/freebsd32/freebsd32_util.h>
 #include <amd64/linux32/linux.h>
 #include <amd64/linux32/linux32_proto.h>
@@ -138,6 +140,7 @@ linux_execve(struct thread *td, struct linux_execve_args *args)
 	free(path, M_TEMP);
 	if (error == 0)
 		error = linux_common_execve(td, &eargs);
+	AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td);
 	return (error);
 }
 
diff --git a/sys/arm64/linux/linux_machdep.c b/sys/arm64/linux/linux_machdep.c
index 058cbe965b1..20e97d02c56 100644
--- a/sys/arm64/linux/linux_machdep.c
+++ b/sys/arm64/linux/linux_machdep.c
@@ -38,6 +38,8 @@ __FBSDID("$FreeBSD$");
 #include <sys/proc.h>
 #include <sys/sdt.h>
 
+#include <security/audit/audit.h>
+
 #include <arm64/linux/linux.h>
 #include <arm64/linux/linux_proto.h>
 #include <compat/linux/linux_dtrace.h>
@@ -74,6 +76,7 @@ linux_execve(struct thread *td, struct linux_execve_args *uap)
 	free(path, M_TEMP);
 	if (error == 0)
 		error = linux_common_execve(td, &eargs);
+	AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td);
 	return (error);
 }
 
diff --git a/sys/compat/freebsd32/freebsd32_misc.c b/sys/compat/freebsd32/freebsd32_misc.c
index 7916f2cefda..c5a622ee228 100644
--- a/sys/compat/freebsd32/freebsd32_misc.c
+++ b/sys/compat/freebsd32/freebsd32_misc.c
@@ -440,6 +440,7 @@ freebsd32_execve(struct thread *td, struct freebsd32_execve_args *uap)
 	if (error == 0)
 		error = kern_execve(td, &eargs, NULL);
 	post_execve(td, error, oldvmspace);
+	AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td);
 	return (error);
 }
 
@@ -460,6 +461,7 @@ freebsd32_fexecve(struct thread *td, struct freebsd32_fexecve_args *uap)
 		error = kern_execve(td, &eargs, NULL);
 	}
 	post_execve(td, error, oldvmspace);
+	AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td);
 	return (error);
 }
 
diff --git a/sys/i386/linux/linux_machdep.c b/sys/i386/linux/linux_machdep.c
index ba106d554ee..ce177e78dc1 100644
--- a/sys/i386/linux/linux_machdep.c
+++ b/sys/i386/linux/linux_machdep.c
@@ -61,6 +61,8 @@ __FBSDID("$FreeBSD$");
 #include <vm/vm.h>
 #include <vm/vm_map.h>
 
+#include <security/audit/audit.h>
+
 #include <i386/linux/linux.h>
 #include <i386/linux/linux_proto.h>
 #include <compat/linux/linux_emul.h>
@@ -111,6 +113,7 @@ linux_execve(struct thread *td, struct linux_execve_args *args)
 	free(newpath, M_TEMP);
 	if (error == 0)
 		error = linux_common_execve(td, &eargs);
+	AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td);
 	return (error);
 }
 
diff --git a/sys/kern/kern_exec.c b/sys/kern/kern_exec.c
index 3f72088644a..f1a498bc626 100644
--- a/sys/kern/kern_exec.c
+++ b/sys/kern/kern_exec.c
@@ -224,6 +224,7 @@ sys_execve(struct thread *td, struct execve_args *uap)
 	if (error == 0)
 		error = kern_execve(td, &args, NULL);
 	post_execve(td, error, oldvmspace);
+	AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td);
 	return (error);
 }
 
@@ -251,6 +252,7 @@ sys_fexecve(struct thread *td, struct fexecve_args *uap)
 		error = kern_execve(td, &args, NULL);
 	}
 	post_execve(td, error, oldvmspace);
+	AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td);
 	return (error);
 }
 
@@ -279,6 +281,7 @@ sys___mac_execve(struct thread *td, struct __mac_execve_args *uap)
 	if (error == 0)
 		error = kern_execve(td, &args, uap->mac_p);
 	post_execve(td, error, oldvmspace);
+	AUDIT_SYSCALL_EXIT(error == EJUSTRETURN ? 0 : error, td);
 	return (error);
 #else
 	return (ENOSYS);
diff --git a/sys/kern/subr_syscall.c b/sys/kern/subr_syscall.c
index 0eb7404f644..728dfed7978 100644
--- a/sys/kern/subr_syscall.c
+++ b/sys/kern/subr_syscall.c
@@ -142,6 +142,16 @@ syscallenter(struct thread *td)
 
 	AUDIT_SYSCALL_ENTER(sa->code, td);
 	error = (sa->callp->sy_call)(td, sa->args);
+
+	/*
+	 * Note that some syscall implementations (e.g., sys_execve)
+	 * will commit the audit record just before their final return.
+	 * These were done under the assumption that nothing of interest
+	 * would happen between their return and here, where we would
+	 * normally commit the audit record.  These assumptions will
+	 * need to be revisited should any substantial logic be added
+	 * above.
+	 */
 	AUDIT_SYSCALL_EXIT(error, td);
 
 	/* Save the latest error return value. */
-- 
2.45.0