diff options
Diffstat (limited to 'libsandbox/libsandbox.c')
| -rw-r--r-- | libsandbox/libsandbox.c | 23 |
1 files changed, 18 insertions, 5 deletions
diff --git a/libsandbox/libsandbox.c b/libsandbox/libsandbox.c index 3bd3794..57be731 100644 --- a/libsandbox/libsandbox.c +++ b/libsandbox/libsandbox.c @@ -240,7 +240,12 @@ static char *resolve_path(const char *path, int follow_link) else ret = realpath(path, filtered_path); - /* Maybe we failed because of funky anonymous fd symlinks. + /* Handle broken symlinks. This can come up for a variety of reasons, + * but we need to make sure that we resolve the path all the way to the + * final target, and not just where the current link happens to start. + * Latest discussion is in #540828. + * + * Maybe we failed because of funky anonymous fd symlinks. * You can see this by doing something like: * $ echo | ls -l /proc/self/fd/ * ....... 0 -> pipe:[9422999] @@ -248,11 +253,19 @@ static char *resolve_path(const char *path, int follow_link) * actual file paths for us to check against. #288863 * Don't look for any particular string as these are dynamic * according to the kernel. You can see pipe:, socket:, etc... + * + * Maybe we failed because it's a symlink to a path in /proc/ that + * is a symlink to a path that longer exists -- readlink will set + * ENOENT even in that case and the file ends in (deleted). This + * can come up in cases like: + * /dev/stderr -> fd/2 -> /proc/self/fd/2 -> /removed/file (deleted) */ - if (!ret && !strncmp(filtered_path, "/proc/", 6)) { - char *base = strrchr(filtered_path, '/'); - if (base && strchr(base, ':')) - ret = filtered_path; + if (!ret && errno == ENOENT) { + ret = canonicalize_filename_mode(path, CAN_ALL_BUT_LAST); + if (ret) { + free(filtered_path); + filtered_path = ret; + } } if (!ret) { |