[PATCH v2] vfio/iommufd: Fix memory leak

[PATCH v2] vfio/iommufd: Fix memory leak

[Cédric Le Goater]

Coverity reported a memory leak on variable 'contents' in routine
iommufd_cdev_getfd(). Use g_autofree variables to simplify the exit
path and get rid of g_free() calls.

Cc: Eric Auger <eric.auger@redhat.com>
Cc: Yi Liu <yi.l.liu@intel.com>
Fixes: CID 1540007
Fixes: 5ee3dc7af785 ("vfio/iommufd: Implement the iommufd backend")
Suggested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
---
 hw/vfio/iommufd.c | 19 ++++++++-----------
 1 file changed, 8 insertions(+), 11 deletions(-)

diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
index a75a785e90c64cdcc4d10c88d217801b3f536cdb..b9c7efb3ef11e49e189103ae6fb9011a631b60da 100644
--- a/hw/vfio/iommufd.c
+++ b/hw/vfio/iommufd.c
@@ -118,10 +118,12 @@ static int iommufd_cdev_getfd(const char *sysfs_path, Error **errp)
 {
     ERRP_GUARD();
     long int ret = -ENOTTY;
-    char *path, *vfio_dev_path = NULL, *vfio_path = NULL;
+    g_autofree char *path = NULL;
+    g_autofree char *vfio_dev_path = NULL;
+    g_autofree char *vfio_path = NULL;
     DIR *dir = NULL;
     struct dirent *dent;
-    gchar *contents;
+    g_autofree gchar *contents = NULL;
     gsize length;
     int major, minor;
     dev_t vfio_devt;
@@ -130,7 +132,7 @@ static int iommufd_cdev_getfd(const char *sysfs_path, Error **errp)
     dir = opendir(path);
     if (!dir) {
         error_setg_errno(errp, errno, "couldn't open directory %s", path);
-        goto out_free_path;
+        goto out;
     }
 
     while ((dent = readdir(dir))) {
@@ -147,14 +149,13 @@ static int iommufd_cdev_getfd(const char *sysfs_path, Error **errp)
 
     if (!g_file_get_contents(vfio_dev_path, &contents, &length, NULL)) {
         error_setg(errp, "failed to load \"%s\"", vfio_dev_path);
-        goto out_free_dev_path;
+        goto out_close_dir;
     }
 
     if (sscanf(contents, "%d:%d", &major, &minor) != 2) {
         error_setg(errp, "failed to get major:minor for \"%s\"", vfio_dev_path);
-        goto out_free_dev_path;
+        goto out_close_dir;
     }
-    g_free(contents);
     vfio_devt = makedev(major, minor);
 
     vfio_path = g_strdup_printf("/dev/vfio/devices/%s", dent->d_name);
@@ -164,17 +165,13 @@ static int iommufd_cdev_getfd(const char *sysfs_path, Error **errp)
     }
 
     trace_iommufd_cdev_getfd(vfio_path, ret);
-    g_free(vfio_path);
 
-out_free_dev_path:
-    g_free(vfio_dev_path);
 out_close_dir:
     closedir(dir);
-out_free_path:
+out:
     if (*errp) {
         error_prepend(errp, VFIO_MSG_PREFIX, path);
     }
-    g_free(path);
 
     return ret;
 }
-- 
2.44.0

RE: [PATCH v2] vfio/iommufd: Fix memory leak

[Duan, Zhenzhong]

>-----Original Message-----
>From: Cédric Le Goater <clg@redhat.com>
>Subject: [PATCH v2] vfio/iommufd: Fix memory leak
>
>Coverity reported a memory leak on variable 'contents' in routine
>iommufd_cdev_getfd(). Use g_autofree variables to simplify the exit
>path and get rid of g_free() calls.
>
>Cc: Eric Auger <eric.auger@redhat.com>
>Cc: Yi Liu <yi.l.liu@intel.com>
>Fixes: CID 1540007
>Fixes: 5ee3dc7af785 ("vfio/iommufd: Implement the iommufd backend")
>Suggested-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
>Signed-off-by: Cédric Le Goater <clg@redhat.com>

Reviewed-by: Zhenzhong Duan <zhenzhong.duan@intel.com>

Thanks
Zhenzhong

>---
> hw/vfio/iommufd.c | 19 ++++++++-----------
> 1 file changed, 8 insertions(+), 11 deletions(-)
>
>diff --git a/hw/vfio/iommufd.c b/hw/vfio/iommufd.c
>index
>a75a785e90c64cdcc4d10c88d217801b3f536cdb..b9c7efb3ef11e49e189103
>ae6fb9011a631b60da 100644
>--- a/hw/vfio/iommufd.c
>+++ b/hw/vfio/iommufd.c
>@@ -118,10 +118,12 @@ static int iommufd_cdev_getfd(const char
>*sysfs_path, Error **errp)
> {
>     ERRP_GUARD();
>     long int ret = -ENOTTY;
>-    char *path, *vfio_dev_path = NULL, *vfio_path = NULL;
>+    g_autofree char *path = NULL;
>+    g_autofree char *vfio_dev_path = NULL;
>+    g_autofree char *vfio_path = NULL;
>     DIR *dir = NULL;
>     struct dirent *dent;
>-    gchar *contents;
>+    g_autofree gchar *contents = NULL;
>     gsize length;
>     int major, minor;
>     dev_t vfio_devt;
>@@ -130,7 +132,7 @@ static int iommufd_cdev_getfd(const char
>*sysfs_path, Error **errp)
>     dir = opendir(path);
>     if (!dir) {
>         error_setg_errno(errp, errno, "couldn't open directory %s", path);
>-        goto out_free_path;
>+        goto out;
>     }
>
>     while ((dent = readdir(dir))) {
>@@ -147,14 +149,13 @@ static int iommufd_cdev_getfd(const char
>*sysfs_path, Error **errp)
>
>     if (!g_file_get_contents(vfio_dev_path, &contents, &length, NULL)) {
>         error_setg(errp, "failed to load \"%s\"", vfio_dev_path);
>-        goto out_free_dev_path;
>+        goto out_close_dir;
>     }
>
>     if (sscanf(contents, "%d:%d", &major, &minor) != 2) {
>         error_setg(errp, "failed to get major:minor for \"%s\"", vfio_dev_path);
>-        goto out_free_dev_path;
>+        goto out_close_dir;
>     }
>-    g_free(contents);
>     vfio_devt = makedev(major, minor);
>
>     vfio_path = g_strdup_printf("/dev/vfio/devices/%s", dent->d_name);
>@@ -164,17 +165,13 @@ static int iommufd_cdev_getfd(const char
>*sysfs_path, Error **errp)
>     }
>
>     trace_iommufd_cdev_getfd(vfio_path, ret);
>-    g_free(vfio_path);
>
>-out_free_dev_path:
>-    g_free(vfio_dev_path);
> out_close_dir:
>     closedir(dir);
>-out_free_path:
>+out:
>     if (*errp) {
>         error_prepend(errp, VFIO_MSG_PREFIX, path);
>     }
>-    g_free(path);
>
>     return ret;
> }
>--
>2.44.0