From 6075c25fa4c1411b072955445f0f4a2418f54b0c Mon Sep 17 00:00:00 2001

From: Djalal Harouni <tixxdz@opendz.org>

Date: Thu, 10 Nov 2016 18:11:37 +0100

Subject: [PATCH] core:namespace: count and free failed paths inside

 chase_all_symlinks() (#4619)

This certainly fixes a bug that was introduced by PR

https://github.com/systemd/systemd/pull/4594 that intended to fix

https://github.com/systemd/systemd/issues/4567.

The fix was not complete. This patch makes sure that we count and free

all paths that fail inside chase_all_symlinks().

Fixes https://github.com/systemd/systemd/issues/4567

(cherry picked from commit 1d54cd5d255065c8659ca68d2591e810e6104714)

---

 src/core/namespace.c | 32 ++++++++++++++++++--------------

 1 file changed, 18 insertions(+), 14 deletions(-)

diff --git a/src/core/namespace.c b/src/core/namespace.c

index b18fcf3e29..49a50c7b61 100644

--- a/src/core/namespace.c

+++ b/src/core/namespace.c

@@ -322,7 +322,7 @@ static void drop_duplicates(BindMount *m, unsigned *n) {

         /* Drops duplicate entries. Expects that the array is properly ordered already. */

-        for (f = m, t = m, previous = NULL; f < m+*n; f++) {

+        for (f = m, t = m, previous = NULL; f < m + *n; f++) {

                 /* The first one wins (which is the one with the more restrictive mode), see mount_path_compare()

                  * above. */

@@ -350,7 +350,7 @@ static void drop_inaccessible(BindMount *m, unsigned *n) {

         /* Drops all entries obstructed by another entry further up the tree. Expects that the array is properly

          * ordered already. */

-        for (f = m, t = m; f < m+*n; f++) {

+        for (f = m, t = m; f < m + *n; f++) {

                 /* If we found a path set for INACCESSIBLE earlier, and this entry has it as prefix we should drop

                  * it, as inaccessible paths really should drop the entire subtree. */

@@ -378,7 +378,7 @@ static void drop_nop(BindMount *m, unsigned *n) {

         /* Drops all entries which have an immediate parent that has the same type, as they are redundant. Assumes the

          * list is ordered by prefixes. */

-        for (f = m, t = m; f < m+*n; f++) {

+        for (f = m, t = m; f < m + *n; f++) {

                 /* Only suppress such subtrees for READONLY and READWRITE entries */

                 if (IN_SET(f->mode, READONLY, READWRITE)) {

@@ -414,12 +414,13 @@ static void drop_outside_root(const char *root_directory, BindMount *m, unsigned

         assert(m);

         assert(n);

+        /* Nothing to do */

         if (!root_directory)

                 return;

         /* Drops all mounts that are outside of the root directory. */

-        for (f = m, t = m; f < m+*n; f++) {

+        for (f = m, t = m; f < m + *n; f++) {

                 if (!path_startswith(f->path, root_directory)) {

                         log_debug("%s is outside of root directory.", f->path);

@@ -663,9 +664,10 @@ static int make_read_only(BindMount *m, char **blacklist) {

         return r;

 }

+/* Chase symlinks and remove failed paths from mounts */

 static int chase_all_symlinks(const char *root_directory, BindMount *m, unsigned *n) {

         BindMount *f, *t;

-        int r;

+        int r = 0;

         assert(m);

         assert(n);

@@ -675,22 +677,24 @@ static int chase_all_symlinks(const char *root_directory, BindMount *m, unsigned

          * can't resolve the path, and which have been marked for such removal. */

         for (f = m, t = m; f < m + *n; f++) {

+                int k;

                 _cleanup_free_ char *chased = NULL;

-                r = chase_symlinks(f->path, root_directory, &chased);

-                if (r == -ENOENT && f->ignore) {

-                        /* Doesn't exist? Then remove it! */

+                k = chase_symlinks(f->path, root_directory, &chased);

+                if (k < 0) {

+                        /* Get only real errors */

+                        if (r >= 0 && (k != -ENOENT || !f->ignore))

+                                r = k;

+

+                        log_debug_errno(r, "Failed to chase symlinks for %s: %m", f->path);

+                        /* Doesn't exist or failed? Then remove it and continue! */

                         f->path = mfree(f->path);

                         continue;

                 }

-                if (r < 0)

-                        return log_debug_errno(r, "Failed to chase symlinks for %s: %m", f->path);

                 if (!path_equal(f->path, chased)) {

                         log_debug("Chased %s → %s", f->path, chased);

-                        r = free_and_replace(f->path, chased);

-                        if (r < 0)

-                                return r;

+                        free_and_replace(f->path, chased);

                 }

                 *t = *f;

@@ -698,7 +702,7 @@ static int chase_all_symlinks(const char *root_directory, BindMount *m, unsigned

         }

         *n = t - m;

-        return 0;

+        return r;

 }

 static unsigned namespace_calculate_mounts(

-- 

2.9.3