diff --git a/init/Android.bp b/init/Android.bp
index dbdf80b..b209c47 100644
--- a/init/Android.bp
+++ b/init/Android.bp
@@ -599,6 +599,7 @@
     ],
     static_libs: [
         "libbase",
+        "libfstab",
         "libselinux",
         "libpropertyinfoserializer",
         "libpropertyinfoparser",
diff --git a/init/service_test.cpp b/init/service_test.cpp
index 53b53ed..d75d4f1 100644
--- a/init/service_test.cpp
+++ b/init/service_test.cpp
@@ -27,6 +27,7 @@
 #include <android-base/file.h>
 #include <android-base/stringprintf.h>
 #include <android-base/strings.h>
+#include <fstab/fstab.h>
 #include <selinux/selinux.h>
 #include <sys/signalfd.h>
 #include "lmkd_service.h"
@@ -280,5 +281,74 @@
 
 INSTANTIATE_TEST_SUITE_P(service, ServiceStopTest, testing::Values(false, true));
 
+// Entering a network namespace requires remounting sysfs to update contents of
+// /sys/class/net whose contents depend on the network namespace of the process
+// that mounted it rather than the effective network namespace of the reading
+// process.
+//
+// A side effect of the remounting is unmounting all filesystems mounted under
+// /sys, like tracefs. Verify that init doesn't leave them unmounted by
+// accident.
+TEST(service, enter_namespace_net_preserves_mounts) {
+    if (getuid() != 0) {
+        GTEST_SKIP() << "Must be run as root.";
+        return;
+    }
+
+    struct ScopedNetNs {
+        std::string name;
+        ScopedNetNs(std::string n) : name(n) {
+            EXPECT_EQ(system(("/system/bin/ip netns add " + name).c_str()), 0);
+        }
+        ~ScopedNetNs() { EXPECT_EQ(system(("/system/bin/ip netns delete " + name).c_str()), 0); }
+    };
+    const ScopedNetNs netns("test_ns");
+
+    static constexpr std::string_view kServiceName = "ServiceA";
+    static constexpr std::string_view kScriptTemplate = R"init(
+service $name /system/bin/yes
+    user shell
+    group shell
+    seclabel $selabel
+    enter_namespace net /mnt/run/$ns_name
+)init";
+
+    std::string script = StringReplace(kScriptTemplate, "$name", kServiceName, false);
+    script = StringReplace(script, "$selabel", GetSecurityContext(), false);
+    script = StringReplace(script, "$ns_name", netns.name, false);
+
+    ServiceList& service_list = ServiceList::GetInstance();
+    Parser parser;
+    parser.AddSectionParser("service", std::make_unique<ServiceParser>(&service_list, nullptr));
+
+    TemporaryFile tf;
+    ASSERT_GE(tf.fd, 0);
+    ASSERT_TRUE(WriteStringToFd(script, tf.fd));
+    ASSERT_TRUE(parser.ParseConfig(tf.path));
+
+    Service* const service = ServiceList::GetInstance().FindService(kServiceName);
+    ASSERT_NE(service, nullptr);
+    ASSERT_RESULT_OK(service->Start());
+    ASSERT_TRUE(service->IsRunning());
+
+    android::fs_mgr::Fstab root_mounts;
+    ASSERT_TRUE(ReadFstabFromFile("/proc/mounts", &root_mounts));
+
+    android::fs_mgr::Fstab ns_mounts;
+    ASSERT_TRUE(ReadFstabFromFile(StringReplace("/proc/$pid/mounts", "$pid",
+                                                std::to_string(service->pid()), /*all=*/false),
+                                  &ns_mounts));
+
+    for (const auto& expected_mount : root_mounts) {
+        auto it = std::find_if(ns_mounts.begin(), ns_mounts.end(), [&](const auto& ns_mount) {
+            return ns_mount.mount_point == expected_mount.mount_point;
+        });
+        EXPECT_TRUE(it != ns_mounts.end()) << StringPrintf(
+                "entering network namespace unmounted %s", expected_mount.mount_point.c_str());
+    }
+
+    ServiceList::GetInstance().RemoveService(*service);
+}
+
 }  // namespace init
 }  // namespace android
diff --git a/init/service_utils.cpp b/init/service_utils.cpp
index 0e19bcc..f8821a0 100644
--- a/init/service_utils.cpp
+++ b/init/service_utils.cpp
@@ -18,11 +18,11 @@
 
 #include <fcntl.h>
 #include <grp.h>
-#include <map>
 #include <sys/mount.h>
 #include <sys/prctl.h>
 #include <sys/wait.h>
 #include <unistd.h>
+#include <map>
 
 #include <android-base/file.h>
 #include <android-base/logging.h>
@@ -31,6 +31,7 @@
 #include <android-base/strings.h>
 #include <cutils/android_get_control_file.h>
 #include <cutils/sockets.h>
+#include <fstab/fstab.h>
 #include <processgroup/processgroup.h>
 
 #include "mount_namespace.h"
@@ -82,12 +83,29 @@
         }
     }
     if (remount_sys) {
+        android::fs_mgr::Fstab mounts;
+        if (!ReadFstabFromFile("/proc/mounts", &mounts)) {
+            LOG(ERROR) << "Could not read /proc/mounts";
+        }
         if (umount2("/sys", MNT_DETACH) == -1) {
             return ErrnoError() << "Could not umount(/sys)";
         }
-        if (mount("", "/sys", "sysfs", kSafeFlags, "") == -1) {
+        if (mount("sysfs", "/sys", "sysfs", kSafeFlags, "") == -1) {
             return ErrnoError() << "Could not mount(/sys)";
         }
+        // Unmounting /sys also unmounts all nested mounts like tracefs.
+        //
+        // Look up the filesystems that were mounted under /sys before we wiped
+        // it and attempt to restore them.
+        for (const auto& entry : mounts) {
+            if (entry.mount_point.starts_with("/sys/")) {
+                if (mount(entry.blk_device.c_str(), entry.mount_point.c_str(),
+                          entry.fs_type.c_str(), entry.flags, "")) {
+                    LOG(WARNING) << "Could not mount(" << entry.mount_point
+                                 << ") after switching netns: " << ErrnoError().str();
+                }
+            }
+        }
     }
     return {};
 }