Storage/posix : Adding error checks in path formation

Renaming directories can cause the size of the buffer
required for posix_handle_path to increase between the
first call, which calculates the size, and the second call
which forms the path in the buffer allocated based on
the size calculated in the first call.

The path created in the second call overflows the
allocated buffer and overwrites the stack causing the
brick process to crash.

The fix adds a buffer size check to prevent the buffer
overflow. It also checks and returns an error if the
posix_handle_path call is unable to form the path instead
of working on the incomplete path, which is likely to cause
subsequent calls using the path to fail with ELOOP.

Preventing buffer overflow and handling errors
BUG: 1113960

Change-Id: If3d3c1952e297ad14f121f05f90a35baf42923aa
Signed-off-by: Nithya Balachandran <nbalacha@redhat.com>
Reviewed-on: http://review.gluster.org/9289
Reviewed-by: Pranith Kumar Karampuri <pkarampu@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Raghavendra Bhat <raghavendra@redhat.com>

4 files changed, 184 insertions, 20 deletions

diff --git a/xlators/storage/posix/src/posix-handle.c b/xlators/storage/posix/src/posix-handle.c
index 7ab654316ee..5d184d930b0 100644
--- a/xlators/storage/posix/src/posix-handle.c
+++ b/xlators/storage/posix/src/posix-handle.c
@@ -296,8 +296,12 @@ posix_handle_pump (xlator_t *this, char *buf, int len, int maxlen,
 
         blen = link_len - 48;
 
-        if(len + blen >= maxlen)
+        if (len + blen >= maxlen) {
+                gf_log (this->name, GF_LOG_ERROR,
+                        "Unable to form handle path for %s (maxlen = %d)",
+                        buf, maxlen);
                 goto err;
+        }
 
         memmove (buf + base_len + blen, buf + base_len,
                  (strlen (buf) - base_len) + 1);
@@ -371,11 +375,11 @@ posix_handle_path (xlator_t *this, uuid_t gfid, const char *basename,
                 errno = 0;
                 ret = posix_handle_pump (this, buf, len, maxlen,
                                          base_str, base_len, pfx_len);
+                len = ret;
+
                 if (ret == -1)
                         break;
 
-                len = ret;
-
                 ret = lstat (buf, &stat);
         } while ((ret == -1) && errno == ELOOP);
 
@@ -841,13 +845,18 @@ posix_handle_unset (xlator_t *this, uuid_t gfid, const char *basename)
         struct iatt  stat;
         char        *path = NULL;
 
-
         if (!basename) {
                 ret = posix_handle_unset_gfid (this, gfid);
                 return ret;
         }
 
         MAKE_HANDLE_PATH (path, this, gfid, basename);
+        if (!path) {
+                gf_log (this->name, GF_LOG_WARNING,
+                        "Failed to create handle path for %s (%s)",
+                        basename, uuid_utoa(gfid));
+                return -1;
+        }
 
         ret = posix_istat (this, gfid, basename, &stat);
 
@@ -872,6 +881,12 @@ posix_create_link_if_gfid_exists (xlator_t *this, uuid_t gfid,
         char *newpath = NULL;
 
         MAKE_HANDLE_PATH (newpath, this, gfid, NULL);
+        if (!newpath) {
+                gf_log (this->name, GF_LOG_WARNING,
+                        "Failed to create handle path (%s)", uuid_utoa(gfid));
+                return ret;
+        }
+
         ret = lstat (newpath, &stbuf);
         if (!ret) {
                 ret = sys_link (newpath, real_path);
diff --git a/xlators/storage/posix/src/posix-handle.h b/xlators/storage/posix/src/posix-handle.h
index 0ce9575251f..3af1a70b31a 100644
--- a/xlators/storage/posix/src/posix-handle.h
+++ b/xlators/storage/posix/src/posix-handle.h
@@ -146,6 +146,8 @@
                 break;                                                  \
         var = alloca (__len);                                           \
         __len = posix_handle_path (this, gfid, base, var, __len);       \
+        if (__len <= 0)                                                 \
+                var = NULL;                                             \
         } while (0)
 
 
@@ -192,7 +194,13 @@
         errno = 0;                                                      \
         op_ret = posix_istat (this, loc->gfid, NULL, iatt_p);           \
         if (errno != ELOOP) {                                           \
-                MAKE_HANDLE_PATH (rpath, this, loc->gfid, NULL);        \
+                MAKE_HANDLE_PATH (rpath, this, (loc)->gfid, NULL);        \
+                if (!rpath) {                                           \
+                        op_ret = -1;                                    \
+                        gf_log (this->name, GF_LOG_ERROR,               \
+                        "Failed to create inode handle "                \
+                        "for path %s", (loc)->path);                      \
+                }                                                       \
                 break;                                                  \
         }                                                               \
         /* __ret == -1 && errno == ELOOP */                             \
@@ -220,6 +228,11 @@
         if (errno != ELOOP) {                                           \
                 MAKE_HANDLE_PATH (parp, this, loc->pargfid, NULL);      \
                 MAKE_HANDLE_PATH (entp, this, loc->pargfid, loc->name); \
+                if (!parp || !entp) {                                   \
+                        gf_log (this->name, GF_LOG_ERROR,               \
+                        "Failed to create entry handle "                \
+                        "for path %s", loc->path);                      \
+                }                                                       \
                 break;                                                  \
         }                                                               \
         /* __ret == -1 && errno == ELOOP */                             \
diff --git a/xlators/storage/posix/src/posix-helpers.c b/xlators/storage/posix/src/posix-helpers.c
index 62b0d2e10fe..2920f318709 100644
--- a/xlators/storage/posix/src/posix-helpers.c
+++ b/xlators/storage/posix/src/posix-helpers.c
@@ -465,10 +465,17 @@ posix_istat (xlator_t *this, uuid_t gfid, const char *basename,
         int          ret = 0;
         struct posix_private *priv = NULL;
 
-
         priv = this->private;
 
         MAKE_HANDLE_PATH (real_path, this, gfid, basename);
+        if (!real_path) {
+                gf_log (this->name, GF_LOG_ERROR,
+                        "Failed to create handle path for %s/%s",
+                        uuid_utoa (gfid), basename ? basename : "");
+                errno = ESTALE;
+                ret = -1;
+                goto out;
+        }
 
         ret = lstat (real_path, &lstatbuf);
 
@@ -819,6 +826,13 @@ posix_get_file_contents (xlator_t *this, uuid_t pargfid,
 
 
         MAKE_HANDLE_PATH (real_path, this, pargfid, name);
+        if (!real_path) {
+                op_ret = -ESTALE;
+                gf_log (this->name, GF_LOG_ERROR,
+                        "Failed to create handle path for %s/%s",
+                        uuid_utoa (pargfid), name);
+                goto out;
+        }
 
         op_ret = posix_istat (this, pargfid, name, &stbuf);
         if (op_ret == -1) {
@@ -1018,10 +1032,12 @@ del_stale_dir_handle (xlator_t *this, uuid_t gfid)
         }
 
         size = posix_handle_path (this, gfid, NULL, newpath, sizeof (newpath));
-        if (size <= 0 && errno == ENOENT) {
-                gf_log (this->name, GF_LOG_DEBUG, "%s: %s", newpath,
-                        strerror (ENOENT));
-                stale = _gf_true;
+        if (size <= 0) {
+                if (errno == ENOENT) {
+                        gf_log (this->name, GF_LOG_DEBUG, "%s: %s", newpath,
+                                strerror (ENOENT));
+                        stale = _gf_true;
+                }
                 goto out;
         }
 
@@ -1380,6 +1396,13 @@ __posix_fd_ctx_get (fd_t *fd, xlator_t *this, struct posix_fd **pfd_p)
                 goto out;
 
         MAKE_HANDLE_PATH (real_path, this, fd->inode->gfid, NULL);
+        if (!real_path) {
+                gf_log (this->name, GF_LOG_ERROR,
+                        "Failed to create handle path (%s)",
+                        uuid_utoa (fd->inode->gfid));
+                ret = -1;
+                goto out;
+        }
 
         pfd = GF_CALLOC (1, sizeof (*pfd), gf_posix_mt_posix_fd);
         if (!pfd) {
diff --git a/xlators/storage/posix/src/posix.c b/xlators/storage/posix/src/posix.c
index 18ff857a5cd..b712ab3f5e8 100644
--- a/xlators/storage/posix/src/posix.c
+++ b/xlators/storage/posix/src/posix.c
@@ -147,7 +147,8 @@ posix_lookup (call_frame_t *frame, xlator_t *this,
                 if (op_errno != ENOENT) {
                         gf_log (this->name, GF_LOG_ERROR,
                                 "lstat on %s failed: %s",
-                                real_path, strerror (op_errno));
+                                real_path ? real_path : "null",
+                                strerror (op_errno));
                 }
 
                 entry_ret = -1;
@@ -243,7 +244,8 @@ posix_stat (call_frame_t *frame, xlator_t *this, loc_t *loc, dict_t *xdata)
                 op_errno = errno;
                 gf_log (this->name, (op_errno == ENOENT)?
                         GF_LOG_DEBUG:GF_LOG_ERROR,
-                        "lstat on %s failed: %s", real_path,
+                        "lstat on %s failed: %s",
+                        real_path ? real_path : "<null>",
                         strerror (op_errno));
                 goto out;
         }
@@ -378,8 +380,8 @@ posix_setattr (call_frame_t *frame, xlator_t *this,
         if (op_ret == -1) {
                 op_errno = errno;
                 gf_log (this->name, GF_LOG_ERROR,
-                        "setattr (lstat) on %s failed: %s", real_path,
-                        strerror (op_errno));
+                        "setattr (lstat) on %s failed: %s",
+                        real_path ? real_path : "<null>", strerror (op_errno));
                 goto out;
         }
 
@@ -905,6 +907,10 @@ posix_opendir (call_frame_t *frame, xlator_t *this,
 
         SET_FS_ID (frame->root->uid, frame->root->gid);
         MAKE_INODE_HANDLE (real_path, this, loc, NULL);
+        if (!real_path) {
+                op_errno = ESTALE;
+                goto out;
+        }
 
         op_ret = -1;
         dir = opendir (real_path);
@@ -1025,7 +1031,8 @@ posix_readlink (call_frame_t *frame, xlator_t *this,
         if (op_ret == -1) {
                 op_errno = errno;
                 gf_log (this->name, GF_LOG_ERROR,
-                        "lstat on %s failed: %s", real_path,
+                        "lstat on %s failed: %s",
+                        loc->path ? loc->path : "<null>",
                         strerror (op_errno));
                 goto out;
         }
@@ -1084,6 +1091,13 @@ posix_mknod (call_frame_t *frame, xlator_t *this,
 
         SET_FS_ID (frame->root->uid, gid);
 
+        if (!real_path || !par_path) {
+                op_ret = -1;
+                op_errno = ESTALE;
+                goto out;
+        }
+
+
         op_ret = posix_pstat (this, loc->pargfid, par_path, &preparent);
         if (op_ret == -1) {
                 op_errno = errno;
@@ -1276,6 +1290,11 @@ posix_mkdir (call_frame_t *frame, xlator_t *this,
         VALIDATE_OR_GOTO (priv, out);
 
         MAKE_ENTRY_HANDLE (real_path, par_path, this, loc, NULL);
+        if (!real_path || !par_path) {
+                op_ret = -1;
+                op_errno = ESTALE;
+                goto out;
+        }
 
         gid = frame->root->gid;
 
@@ -1466,6 +1485,11 @@ posix_unlink (call_frame_t *frame, xlator_t *this,
 
         SET_FS_ID (frame->root->uid, frame->root->gid);
         MAKE_ENTRY_HANDLE (real_path, par_path, this, loc, &stbuf);
+        if (!real_path || !par_path) {
+                op_ret = -1;
+                op_errno = ESTALE;
+                goto out;
+        }
 
         op_ret = posix_pstat (this, loc->pargfid, par_path, &preparent);
         if (op_ret == -1) {
@@ -1634,6 +1658,11 @@ posix_rmdir (call_frame_t *frame, xlator_t *this,
         priv = this->private;
 
         MAKE_ENTRY_HANDLE (real_path, par_path, this, loc, &stbuf);
+        if (!real_path || !par_path) {
+                op_ret = -1;
+                op_errno = ESTALE;
+                goto out;
+        }
 
         op_ret = posix_pstat (this, loc->pargfid, par_path, &preparent);
         if (op_ret == -1) {
@@ -1730,6 +1759,11 @@ posix_symlink (call_frame_t *frame, xlator_t *this,
         MAKE_ENTRY_HANDLE (real_path, par_path, this, loc, &stbuf);
 
         gid = frame->root->gid;
+        if (!real_path || !par_path) {
+                op_ret = -1;
+                op_errno = ESTALE;
+                goto out;
+        }
 
         SET_FS_ID (frame->root->uid, gid);
 
@@ -1874,7 +1908,18 @@ posix_rename (call_frame_t *frame, xlator_t *this,
 
         SET_FS_ID (frame->root->uid, frame->root->gid);
         MAKE_ENTRY_HANDLE (real_oldpath, par_oldpath, this, oldloc, NULL);
+        if (!real_oldpath || !par_oldpath) {
+                op_ret = -1;
+                op_errno = ESTALE;
+                goto out;
+        }
+
         MAKE_ENTRY_HANDLE (real_newpath, par_newpath, this, newloc, &stbuf);
+        if (!real_newpath || !par_newpath) {
+                op_ret = -1;
+                op_errno = ESTALE;
+                goto out;
+        }
 
         op_ret = posix_pstat (this, oldloc->pargfid, par_oldpath, &preoldparent);
         if (op_ret == -1) {
@@ -2067,8 +2112,17 @@ posix_link (call_frame_t *frame, xlator_t *this,
 
         SET_FS_ID (frame->root->uid, frame->root->gid);
         MAKE_INODE_HANDLE (real_oldpath, this, oldloc, &stbuf);
+        if (!real_oldpath) {
+                op_errno = errno;
+                goto out;
+        }
 
         MAKE_ENTRY_HANDLE (real_newpath, par_newpath, this, newloc, &stbuf);
+        if (!real_newpath || !par_newpath) {
+                op_ret = -1;
+                op_errno = ESTALE;
+                goto out;
+        }
 
         op_ret = posix_pstat (this, newloc->pargfid, par_newpath, &preparent);
         if (op_ret == -1) {
@@ -2174,7 +2228,7 @@ posix_truncate (call_frame_t *frame, xlator_t *this, loc_t *loc, off_t offset,
                 op_errno = errno;
                 gf_log (this->name, GF_LOG_ERROR,
                         "pre-operation lstat on %s failed: %s",
-                        real_path, strerror (op_errno));
+                        real_path ? real_path : "<null>", strerror (op_errno));
                 goto out;
         }
 
@@ -2246,6 +2300,11 @@ posix_create (call_frame_t *frame, xlator_t *this,
         gid = frame->root->gid;
 
         SET_FS_ID (frame->root->uid, gid);
+        if (!real_path || !par_path) {
+                op_ret = -1;
+                op_errno = ESTALE;
+                goto out;
+        }
 
         op_ret = posix_pstat (this, loc->pargfid, par_path, &preparent);
         if (op_ret == -1) {
@@ -2421,6 +2480,11 @@ posix_open (call_frame_t *frame, xlator_t *this,
         VALIDATE_OR_GOTO (priv, out);
 
         MAKE_INODE_HANDLE (real_path, this, loc, &stbuf);
+        if (!real_path) {
+                op_ret = -1;
+                op_errno = ESTALE;
+                goto out;
+        }
 
         if (IA_ISLNK (stbuf.ia_type)) {
                 op_ret = -1;
@@ -2842,6 +2906,11 @@ posix_statfs (call_frame_t *frame, xlator_t *this,
         VALIDATE_OR_GOTO (this->private, out);
 
         MAKE_INODE_HANDLE (real_path, this, loc, NULL);
+        if (!real_path) {
+                op_ret = -1;
+                op_errno = ESTALE;
+                goto out;
+        }
 
         priv = this->private;
 
@@ -3116,6 +3185,11 @@ posix_setxattr (call_frame_t *frame, xlator_t *this,
         VALIDATE_OR_GOTO (dict, out);
 
         MAKE_INODE_HANDLE (real_path, this, loc, NULL);
+        if (!real_path) {
+                op_ret = -1;
+                op_errno = ESTALE;
+                goto out;
+        }
 
         op_ret = -1;
         dict_del (dict, GFID_XATTR_KEY);
@@ -3157,6 +3231,9 @@ posix_xattr_get_real_filename (call_frame_t *frame, xlator_t *this, loc_t *loc,
 	int op_ret = -1;
 
         MAKE_INODE_HANDLE (real_path, this, loc, NULL);
+        if (!real_path) {
+                return -ESTALE;
+        }
 
 	fd = opendir (real_path);
 	if (!fd)
@@ -3375,7 +3452,10 @@ posix_get_ancestry_non_directory (xlator_t *this, inode_t *leaf_inode,
         uuid_copy (loc->gfid, leaf_inode->gfid);
 
         MAKE_INODE_HANDLE (leaf_path, this, loc, NULL);
-
+        if (!leaf_path) {
+                GF_FREE (loc);
+                goto out;
+        }
         GF_FREE (loc);
 
         size = sys_llistxattr (leaf_path, NULL, 0);
@@ -4217,6 +4297,12 @@ posix_removexattr (call_frame_t *frame, xlator_t *this,
         DECLARE_OLD_FS_ID_VAR;
 
         MAKE_INODE_HANDLE (real_path, this, loc, NULL);
+        if (!real_path) {
+                op_ret = -1;
+                op_errno = ESTALE;
+                goto out;
+        }
+
 
         if (!strcmp (GFID_XATTR_KEY, name)) {
                 gf_log (this->name, GF_LOG_WARNING, "Remove xattr called"
@@ -4642,6 +4728,11 @@ posix_access (call_frame_t *frame, xlator_t *this,
         VALIDATE_OR_GOTO (loc, out);
 
         MAKE_INODE_HANDLE (real_path, this, loc, NULL);
+        if (!real_path) {
+                op_ret = -1;
+                op_errno = errno;
+                goto out;
+        }
 
         op_ret = access (real_path, mask & 07);
         if (op_ret == -1) {
@@ -4887,8 +4978,20 @@ posix_fill_readdir (fd_t *fd, DIR *dir, off_t off, size_t size,
 
         if (skip_dirs) {
                 len = posix_handle_path (this, fd->inode->gfid, NULL, NULL, 0);
+                if (len <= 0) {
+                        errno = ESTALE;
+                        count = -1;
+                        goto out;
+                }
                 hpath = alloca (len + 256); /* NAME_MAX */
-                posix_handle_path (this, fd->inode->gfid, NULL, hpath, len);
+
+                if (posix_handle_path (this, fd->inode->gfid, NULL, hpath,
+                                       len) <= 0) {
+                        errno = ESTALE;
+                        count = -1;
+                        goto out;
+                }
+
                 len = strlen (hpath);
                 hpath[len] = '/';
         }
@@ -5033,7 +5136,13 @@ posix_entry_xattr_fill (xlator_t *this, inode_t *inode,
         tmp_loc.inode = inode;
 
         MAKE_HANDLE_PATH (entry_path, this, fd->inode->gfid, name);
+        if (!entry_path) {
+                gf_log (this->name, GF_LOG_WARNING,
+                        "Failed to create handle path for %s (%s)",
+                        name, uuid_utoa (fd->inode->gfid));
 
+                return NULL;
+        }
         return posix_lookup_xattr_fill (this, entry_path,
                                         &tmp_loc, dict, stbuf);
 
@@ -5057,8 +5166,11 @@ posix_readdirp_fill (xlator_t *this, fd_t *fd, gf_dirent_t *entries, dict_t *dic
         itable = fd->inode->table;
 
 	len = posix_handle_path (this, fd->inode->gfid, NULL, NULL, 0);
+        if (len <= 0)
+                return -1;
 	hpath = alloca (len + 256); /* NAME_MAX */
-	posix_handle_path (this, fd->inode->gfid, NULL, hpath, len);
+	if (posix_handle_path (this, fd->inode->gfid, NULL, hpath, len) <= 0)
+                return -1;
 	len = strlen (hpath);
 	hpath[len] = '/';
 
@@ -5089,7 +5201,8 @@ posix_readdirp_fill (xlator_t *this, fd_t *fd, gf_dirent_t *entries, dict_t *dic
                                 posix_entry_xattr_fill (this, entry->inode,
                                                         fd, entry->d_name,
                                                         dict, &stbuf);
-                        dict_ref (entry->dict);
+                        if (entry->dict)
+                                dict_ref (entry->dict);
                 }
 
                 entry->d_stat = stbuf;