Properly bzero kldstat structure to prevent information leak. [SA-17:10]

Approved by:	so
Security:	FreeBSD-SA-17:10.kldstat
Security:	CVE-2017-1088

4 files changed, 33 insertions, 19 deletions

diff --git a/UPDATING b/UPDATING
index ab284df..6f1bd5e 100644
--- a/UPDATING
+++ b/UPDATING
@@ -16,6 +16,13 @@ from older versions of FreeBSD, try WITHOUT_CLANG and WITH_GCC to bootstrap to
 the tip of head, and then rebuild without this option. The bootstrap process
 from older version of current across the gcc/clang cutover is a bit fragile.
 
+20171115	p3	FreeBSD-SA-17:08.ptrace
+			FreeBSD-SA-17:10.kldstat
+
+	Fix ptrace(2) vulnerability. [SA-17:08.ptrace]
+
+	Fix kldstat(2) vulnerability. [SA-17:10.kldstat]
+
 20171102	p3	FreeBSD-EN-17:09.tzdata
 
 	Update timezone database information. [EN-17:09]
diff --git a/sys/compat/freebsd32/freebsd32_misc.c b/sys/compat/freebsd32/freebsd32_misc.c
index a8e69b7..c097cf3 100644
--- a/sys/compat/freebsd32/freebsd32_misc.c
+++ b/sys/compat/freebsd32/freebsd32_misc.c
@@ -2950,8 +2950,8 @@ freebsd32_copyout_strings(struct image_params *imgp)
 int
 freebsd32_kldstat(struct thread *td, struct freebsd32_kldstat_args *uap)
 {
-	struct kld_file_stat stat;
-	struct kld32_file_stat stat32;
+	struct kld_file_stat *stat;
+	struct kld32_file_stat *stat32;
 	int error, version;
 
 	if ((error = copyin(&uap->stat->version, &version, sizeof(version)))
@@ -2961,17 +2961,22 @@ freebsd32_kldstat(struct thread *td, struct freebsd32_kldstat_args *uap)
 	    version != sizeof(struct kld32_file_stat))
 		return (EINVAL);
 
-	error = kern_kldstat(td, uap->fileid, &stat);
-	if (error != 0)
-		return (error);
-
-	bcopy(&stat.name[0], &stat32.name[0], sizeof(stat.name));
-	CP(stat, stat32, refs);
-	CP(stat, stat32, id);
-	PTROUT_CP(stat, stat32, address);
-	CP(stat, stat32, size);
-	bcopy(&stat.pathname[0], &stat32.pathname[0], sizeof(stat.pathname));
-	return (copyout(&stat32, uap->stat, version));
+	stat = malloc(sizeof(*stat), M_TEMP, M_WAITOK | M_ZERO);
+	stat32 = malloc(sizeof(*stat32), M_TEMP, M_WAITOK | M_ZERO);
+	error = kern_kldstat(td, uap->fileid, stat);
+	if (error == 0) {
+		bcopy(&stat->name[0], &stat32->name[0], sizeof(stat->name));
+		CP(*stat, *stat32, refs);
+		CP(*stat, *stat32, id);
+		PTROUT_CP(*stat, *stat32, address);
+		CP(*stat, *stat32, size);
+		bcopy(&stat->pathname[0], &stat32->pathname[0],
+		    sizeof(stat->pathname));
+		error = copyout(stat32, uap->stat, version);
+	}
+	free(stat, M_TEMP);
+	free(stat32, M_TEMP);
+	return (error);
 }
 
 int
diff --git a/sys/conf/newvers.sh b/sys/conf/newvers.sh
index 6d03232..6e7f7f2 100644
--- a/sys/conf/newvers.sh
+++ b/sys/conf/newvers.sh
@@ -44,7 +44,7 @@
 
 TYPE="FreeBSD"
 REVISION="11.1"
-BRANCH="RELEASE-p3"
+BRANCH="RELEASE-p4"
 if [ -n "${BRANCH_OVERRIDE}" ]; then
 	BRANCH=${BRANCH_OVERRIDE}
 fi
diff --git a/sys/kern/kern_linker.c b/sys/kern/kern_linker.c
index 4758cdc..6c653da 100644
--- a/sys/kern/kern_linker.c
+++ b/sys/kern/kern_linker.c
@@ -1201,7 +1201,7 @@ out:
 int
 sys_kldstat(struct thread *td, struct kldstat_args *uap)
 {
-	struct kld_file_stat stat;
+	struct kld_file_stat *stat;
 	int error, version;
 
 	/*
@@ -1214,10 +1214,12 @@ sys_kldstat(struct thread *td, struct kldstat_args *uap)
 	    version != sizeof(struct kld_file_stat))
 		return (EINVAL);
 
-	error = kern_kldstat(td, uap->fileid, &stat);
-	if (error != 0)
-		return (error);
-	return (copyout(&stat, uap->stat, version));
+	stat = malloc(sizeof(*stat), M_TEMP, M_WAITOK | M_ZERO);
+	error = kern_kldstat(td, uap->fileid, stat);
+	if (error == 0)
+		error = copyout(stat, uap->stat, version);
+	free(stat, M_TEMP);
+	return (error);
 }
 
 int