storage/posix: handle getxattr failures gracefully

Use proper variable types for getting return value of getxattr calls,
which otherwise can lead to segfaulting of processes or page allocation
failures in the kernel.

Change-Id: Idc41b4022401c238d17ba357648234f7c2d56c87
BUG: 838195
Signed-off-by: Raghavendra Bhat <raghavendra@redhat.com>
Reviewed-on: http://review.gluster.com/3658
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

1 files changed, 25 insertions, 9 deletions

diff --git a/xlators/storage/posix/src/posix-helpers.c b/xlators/storage/posix/src/posix-helpers.c
index 06b5cedcb..f4dcc70a2 100644
--- a/xlators/storage/posix/src/posix-helpers.c
+++ b/xlators/storage/posix/src/posix-helpers.c
@@ -214,16 +214,25 @@ _posix_xattr_get_set (dict_t *xattr_req,
                         if (!value)
                                 return;
 
-                        sys_lgetxattr (filler->real_path, key, value,
-                                       xattr_size);
+                        xattr_size = sys_lgetxattr (filler->real_path, key,
+                                                    value, xattr_size);
+                        if (xattr_size <= 0) {
+                                gf_log (filler->this->name, GF_LOG_WARNING,
+                                        "getxattr failed. path: %s, key: %s",
+                                        filler->real_path, key);
+                                GF_FREE (value);
+                                return;
+                        }
 
                         value[xattr_size] = '\0';
                         ret = dict_set_bin (filler->xattr, key,
                                             value, xattr_size);
-                        if (ret < 0)
+                        if (ret < 0) {
                                 gf_log (filler->this->name, GF_LOG_DEBUG,
                                         "dict set failed. path: %s, key: %s",
                                         filler->real_path, key);
+                                GF_FREE (value);
+                        }
                 }
         }
 out:
@@ -235,14 +244,17 @@ int
 posix_fill_gfid_path (xlator_t *this, const char *path, struct iatt *iatt)
 {
         int ret = 0;
+        ssize_t  size = 0;
 
         if (!iatt)
                 return 0;
 
-        ret = sys_lgetxattr (path, GFID_XATTR_KEY, iatt->ia_gfid, 16);
+        size = sys_lgetxattr (path, GFID_XATTR_KEY, iatt->ia_gfid, 16);
         /* Return value of getxattr */
-        if ((ret == 16) || (ret == -1))
+        if ((size == 16) || (size == -1))
                 ret = 0;
+        else
+                ret = size;
 
         return ret;
 }
@@ -252,14 +264,17 @@ int
 posix_fill_gfid_fd (xlator_t *this, int fd, struct iatt *iatt)
 {
         int ret = 0;
+        ssize_t  size = 0;
 
         if (!iatt)
                 return 0;
 
-        ret = sys_fgetxattr (fd, GFID_XATTR_KEY, iatt->ia_gfid, 16);
+        size = sys_fgetxattr (fd, GFID_XATTR_KEY, iatt->ia_gfid, 16);
         /* Return value of getxattr */
-        if ((ret == 16) || (ret == -1))
+        if ((size == 16) || (size == -1))
                 ret = 0;
+        else
+                ret = size;
 
         return ret;
 }
@@ -443,6 +458,7 @@ posix_gfid_set (xlator_t *this, const char *path, loc_t *loc, dict_t *xattr_req)
         void        *uuid_req = NULL;
         uuid_t       uuid_curr;
         int          ret = 0;
+        ssize_t      size = 0;
         struct stat  stat = {0, };
 
 
@@ -452,8 +468,8 @@ posix_gfid_set (xlator_t *this, const char *path, loc_t *loc, dict_t *xattr_req)
         if (sys_lstat (path, &stat) != 0)
                 goto out;
 
-        ret = sys_lgetxattr (path, GFID_XATTR_KEY, uuid_curr, 16);
-        if (ret == 16) {
+        size = sys_lgetxattr (path, GFID_XATTR_KEY, uuid_curr, 16);
+        if (size == 16) {
                 ret = 0;
                 goto verify_handle;
         }