s3-vfs: Prevent NULL pointer dereference in vfs_glusterfs.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=13708

Guenther

Signed-off-by: Guenther Deschner <gd@samba.org>
Reviewed-by: Ralph Boehme <slow@samba.org>

Autobuild-User(master): Günther Deschner <gd@samba.org>
Autobuild-Date(master): Tue Dec 11 17:26:31 CET 2018 on sn-devel-144

(cherry picked from commit 75d15484f3b71b1a2684c4a73e53aaa467f9932b)

1 files changed, 168 insertions, 32 deletions

diff --git a/source3/modules/vfs_glusterfs.c b/source3/modules/vfs_glusterfs.c
index 38abb78f1f3..e6448cc874a 100644
--- a/source3/modules/vfs_glusterfs.c
+++ b/source3/modules/vfs_glusterfs.c
@@ -491,11 +491,33 @@ static DIR *vfs_gluster_opendir(struct vfs_handle_struct *handle,
 	return (DIR *) fd;
 }
 
+static glfs_fd_t *vfs_gluster_fetch_glfd(struct vfs_handle_struct *handle,
+					 files_struct *fsp)
+{
+	glfs_fd_t **glfd = (glfs_fd_t **)VFS_FETCH_FSP_EXTENSION(handle, fsp);
+	if (glfd == NULL) {
+		DBG_INFO("Failed to fetch fsp extension\n");
+		return NULL;
+	}
+	if (*glfd == NULL) {
+		DBG_INFO("Empty glfs_fd_t pointer\n");
+		return NULL;
+	}
+
+	return *glfd;
+}
+
 static DIR *vfs_gluster_fdopendir(struct vfs_handle_struct *handle,
 				  files_struct *fsp, const char *mask,
 				  uint32_t attributes)
 {
-	return (DIR *) *(glfs_fd_t **)VFS_FETCH_FSP_EXTENSION(handle, fsp);
+	glfs_fd_t *glfd = vfs_gluster_fetch_glfd(handle, fsp);
+	if (glfd == NULL) {
+		DBG_ERR("Failed to fetch gluster fd\n");
+		return NULL;
+	}
+
+	return (DIR *)glfd;
 }
 
 static int vfs_gluster_closedir(struct vfs_handle_struct *handle, DIR *dirp)
@@ -586,8 +608,12 @@ static int vfs_gluster_open(struct vfs_handle_struct *handle,
 static int vfs_gluster_close(struct vfs_handle_struct *handle,
 			     files_struct *fsp)
 {
-	glfs_fd_t *glfd;
-	glfd = *(glfs_fd_t **)VFS_FETCH_FSP_EXTENSION(handle, fsp);
+	glfs_fd_t *glfd = vfs_gluster_fetch_glfd(handle, fsp);
+	if (glfd == NULL) {
+		DBG_ERR("Failed to fetch gluster fd\n");
+		return -1;
+	}
+
 	VFS_REMOVE_FSP_EXTENSION(handle, fsp);
 	return glfs_close(glfd);
 }
@@ -595,14 +621,26 @@ static int vfs_gluster_close(struct vfs_handle_struct *handle,
 static ssize_t vfs_gluster_read(struct vfs_handle_struct *handle,
 				files_struct *fsp, void *data, size_t n)
 {
-	return glfs_read(*(glfs_fd_t **)VFS_FETCH_FSP_EXTENSION(handle, fsp), data, n, 0);
+	glfs_fd_t *glfd = vfs_gluster_fetch_glfd(handle, fsp);
+	if (glfd == NULL) {
+		DBG_ERR("Failed to fetch gluster fd\n");
+		return -1;
+	}
+
+	return glfs_read(glfd, data, n, 0);
 }
 
 static ssize_t vfs_gluster_pread(struct vfs_handle_struct *handle,
 				 files_struct *fsp, void *data, size_t n,
 				 off_t offset)
 {
-	return glfs_pread(*(glfs_fd_t **)VFS_FETCH_FSP_EXTENSION(handle, fsp), data, n, offset, 0);
+	glfs_fd_t *glfd = vfs_gluster_fetch_glfd(handle, fsp);
+	if (glfd == NULL) {
+		DBG_ERR("Failed to fetch gluster fd\n");
+		return -1;
+	}
+
+	return glfs_pread(glfd, data, n, offset, 0);
 }
 
 struct glusterfs_aio_state;
@@ -795,6 +833,12 @@ static struct tevent_req *vfs_gluster_pread_send(struct vfs_handle_struct
 	struct glusterfs_aio_state *state = NULL;
 	struct tevent_req *req = NULL;
 	int ret = 0;
+	glfs_fd_t *glfd = vfs_gluster_fetch_glfd(handle, fsp);
+
+	if (glfd == NULL) {
+		DBG_ERR("Failed to fetch gluster fd\n");
+		return NULL;
+	}
 
 	state = aio_state_create(mem_ctx);
 
@@ -810,8 +854,7 @@ static struct tevent_req *vfs_gluster_pread_send(struct vfs_handle_struct
 	}
 
 	PROFILE_TIMESTAMP(&state->start);
-	ret = glfs_pread_async(*(glfs_fd_t **)VFS_FETCH_FSP_EXTENSION(handle,
-				fsp), data, n, offset, 0, aio_glusterfs_done,
+	ret = glfs_pread_async(glfd, data, n, offset, 0, aio_glusterfs_done,
 				state);
 	if (ret < 0) {
 		tevent_req_error(req, -ret);
@@ -831,6 +874,12 @@ static struct tevent_req *vfs_gluster_pwrite_send(struct vfs_handle_struct
 	struct glusterfs_aio_state *state = NULL;
 	struct tevent_req *req = NULL;
 	int ret = 0;
+	glfs_fd_t *glfd = vfs_gluster_fetch_glfd(handle, fsp);
+
+	if (glfd == NULL) {
+		DBG_ERR("Failed to fetch gluster fd\n");
+		return NULL;
+	}
 
 	state = aio_state_create(mem_ctx);
 
@@ -846,8 +895,7 @@ static struct tevent_req *vfs_gluster_pwrite_send(struct vfs_handle_struct
 	}
 
 	PROFILE_TIMESTAMP(&state->start);
-	ret = glfs_pwrite_async(*(glfs_fd_t **)VFS_FETCH_FSP_EXTENSION(handle,
-				fsp), data, n, offset, 0, aio_glusterfs_done,
+	ret = glfs_pwrite_async(glfd, data, n, offset, 0, aio_glusterfs_done,
 				state);
 	if (ret < 0) {
 		tevent_req_error(req, -ret);
@@ -890,20 +938,38 @@ static ssize_t vfs_gluster_recv(struct tevent_req *req,
 static ssize_t vfs_gluster_write(struct vfs_handle_struct *handle,
 				 files_struct *fsp, const void *data, size_t n)
 {
-	return glfs_write(*(glfs_fd_t **)VFS_FETCH_FSP_EXTENSION(handle, fsp), data, n, 0);
+	glfs_fd_t *glfd = vfs_gluster_fetch_glfd(handle, fsp);
+	if (glfd == NULL) {
+		DBG_ERR("Failed to fetch gluster fd\n");
+		return -1;
+	}
+
+	return glfs_write(glfd, data, n, 0);
 }
 
 static ssize_t vfs_gluster_pwrite(struct vfs_handle_struct *handle,
 				  files_struct *fsp, const void *data,
 				  size_t n, off_t offset)
 {
-	return glfs_pwrite(*(glfs_fd_t **)VFS_FETCH_FSP_EXTENSION(handle, fsp), data, n, offset, 0);
+	glfs_fd_t *glfd = vfs_gluster_fetch_glfd(handle, fsp);
+	if (glfd == NULL) {
+		DBG_ERR("Failed to fetch gluster fd\n");
+		return -1;
+	}
+
+	return glfs_pwrite(glfd, data, n, offset, 0);
 }
 
 static off_t vfs_gluster_lseek(struct vfs_handle_struct *handle,
 			       files_struct *fsp, off_t offset, int whence)
 {
-	return glfs_lseek(*(glfs_fd_t **)VFS_FETCH_FSP_EXTENSION(handle, fsp), offset, whence);
+	glfs_fd_t *glfd = vfs_gluster_fetch_glfd(handle, fsp);
+	if (glfd == NULL) {
+		DBG_ERR("Failed to fetch gluster fd\n");
+		return -1;
+	}
+
+	return glfs_lseek(glfd, offset, whence);
 }
 
 static ssize_t vfs_gluster_sendfile(struct vfs_handle_struct *handle, int tofd,
@@ -934,7 +1000,13 @@ static int vfs_gluster_rename(struct vfs_handle_struct *handle,
 static int vfs_gluster_fsync(struct vfs_handle_struct *handle,
 			     files_struct *fsp)
 {
-	return glfs_fsync(*(glfs_fd_t **)VFS_FETCH_FSP_EXTENSION(handle, fsp));
+	glfs_fd_t *glfd = vfs_gluster_fetch_glfd(handle, fsp);
+	if (glfd == NULL) {
+		DBG_ERR("Failed to fetch gluster fd\n");
+		return -1;
+	}
+
+	return glfs_fsync(glfd);
 }
 
 static struct tevent_req *vfs_gluster_fsync_send(struct vfs_handle_struct
@@ -945,6 +1017,12 @@ static struct tevent_req *vfs_gluster_fsync_send(struct vfs_handle_struct
 	struct tevent_req *req = NULL;
 	struct glusterfs_aio_state *state = NULL;
 	int ret = 0;
+	glfs_fd_t *glfd = vfs_gluster_fetch_glfd(handle, fsp);
+
+	if (glfd == NULL) {
+		DBG_ERR("Failed to fetch gluster fd\n");
+		return NULL;
+	}
 
 	state = aio_state_create(mem_ctx);
 
@@ -960,8 +1038,7 @@ static struct tevent_req *vfs_gluster_fsync_send(struct vfs_handle_struct
 	}
 
 	PROFILE_TIMESTAMP(&state->start);
-	ret = glfs_fsync_async(*(glfs_fd_t **)VFS_FETCH_FSP_EXTENSION(handle,
-				fsp), aio_glusterfs_done, state);
+	ret = glfs_fsync_async(glfd, aio_glusterfs_done, state);
 	if (ret < 0) {
 		tevent_req_error(req, -ret);
 		return tevent_req_post(req, ev);
@@ -1000,8 +1077,14 @@ static int vfs_gluster_fstat(struct vfs_handle_struct *handle,
 {
 	struct stat st;
 	int ret;
+	glfs_fd_t *glfd = vfs_gluster_fetch_glfd(handle, fsp);
 
-	ret = glfs_fstat(*(glfs_fd_t **)VFS_FETCH_FSP_EXTENSION(handle, fsp), &st);
+	if (glfd == NULL) {
+		DBG_ERR("Failed to fetch gluster fd\n");
+		return -1;
+	}
+
+	ret = glfs_fstat(glfd, &st);
 	if (ret == 0) {
 		smb_stat_ex_from_stat(sbuf, &st);
 	}
@@ -1052,7 +1135,14 @@ static int vfs_gluster_chmod(struct vfs_handle_struct *handle,
 static int vfs_gluster_fchmod(struct vfs_handle_struct *handle,
 			      files_struct *fsp, mode_t mode)
 {
-	return glfs_fchmod(*(glfs_fd_t **)VFS_FETCH_FSP_EXTENSION(handle, fsp), mode);
+	glfs_fd_t *glfd = vfs_gluster_fetch_glfd(handle, fsp);
+
+	if (glfd == NULL) {
+		DBG_ERR("Failed to fetch gluster fd\n");
+		return -1;
+	}
+
+	return glfs_fchmod(glfd, mode);
 }
 
 static int vfs_gluster_chown(struct vfs_handle_struct *handle,
@@ -1066,7 +1156,13 @@ static int vfs_gluster_chown(struct vfs_handle_struct *handle,
 static int vfs_gluster_fchown(struct vfs_handle_struct *handle,
 			      files_struct *fsp, uid_t uid, gid_t gid)
 {
-	return glfs_fchown(*(glfs_fd_t **)VFS_FETCH_FSP_EXTENSION(handle, fsp), uid, gid);
+	glfs_fd_t *glfd = vfs_gluster_fetch_glfd(handle, fsp);
+	if (glfd == NULL) {
+		DBG_ERR("Failed to fetch gluster fd\n");
+		return -1;
+	}
+
+	return glfs_fchown(glfd, uid, gid);
 }
 
 static int vfs_gluster_lchown(struct vfs_handle_struct *handle,
@@ -1144,7 +1240,13 @@ static int vfs_gluster_ntimes(struct vfs_handle_struct *handle,
 static int vfs_gluster_ftruncate(struct vfs_handle_struct *handle,
 				 files_struct *fsp, off_t offset)
 {
-	return glfs_ftruncate(*(glfs_fd_t **)VFS_FETCH_FSP_EXTENSION(handle, fsp), offset);
+	glfs_fd_t *glfd = vfs_gluster_fetch_glfd(handle, fsp);
+	if (glfd == NULL) {
+		DBG_ERR("Failed to fetch gluster fd\n");
+		return -1;
+	}
+
+	return glfs_ftruncate(glfd, offset);
 }
 
 static int vfs_gluster_fallocate(struct vfs_handle_struct *handle,
@@ -1154,6 +1256,11 @@ static int vfs_gluster_fallocate(struct vfs_handle_struct *handle,
 {
 #ifdef HAVE_GFAPI_VER_6
 	int keep_size, punch_hole;
+	glfs_fd_t *glfd = vfs_gluster_fetch_glfd(handle, fsp);
+	if (glfd == NULL) {
+		DBG_ERR("Failed to fetch gluster fd\n");
+		return -1;
+	}
 
 	keep_size = mode & VFS_FALLOCATE_FL_KEEP_SIZE;
 	punch_hole = mode & VFS_FALLOCATE_FL_PUNCH_HOLE;
@@ -1165,14 +1272,10 @@ static int vfs_gluster_fallocate(struct vfs_handle_struct *handle,
 	}
 
 	if (punch_hole) {
-		return glfs_discard(*(glfs_fd_t **)
-				    VFS_FETCH_FSP_EXTENSION(handle, fsp),
-				    offset, len);
+		return glfs_discard(glfd, offset, len);
 	}
 
-	return glfs_fallocate(*(glfs_fd_t **)
-			      VFS_FETCH_FSP_EXTENSION(handle, fsp),
-			      keep_size, offset, len);
+	return glfs_fallocate(glfd, keep_size, offset, len);
 #else
 	errno = ENOTSUP;
 	return -1;
@@ -1209,6 +1312,11 @@ static bool vfs_gluster_lock(struct vfs_handle_struct *handle,
 {
 	struct flock flock = { 0, };
 	int ret;
+	glfs_fd_t *glfd = vfs_gluster_fetch_glfd(handle, fsp);
+	if (glfd == NULL) {
+		DBG_ERR("Failed to fetch gluster fd\n");
+		return false;
+	}
 
 	flock.l_type = type;
 	flock.l_whence = SEEK_SET;
@@ -1216,7 +1324,7 @@ static bool vfs_gluster_lock(struct vfs_handle_struct *handle,
 	flock.l_len = count;
 	flock.l_pid = 0;
 
-	ret = glfs_posix_lock(*(glfs_fd_t **)VFS_FETCH_FSP_EXTENSION(handle, fsp), op, &flock);
+	ret = glfs_posix_lock(glfd, op, &flock);
 
 	if (op == F_GETLK) {
 		/* lock query, true if someone else has locked */
@@ -1256,6 +1364,11 @@ static bool vfs_gluster_getlock(struct vfs_handle_struct *handle,
 {
 	struct flock flock = { 0, };
 	int ret;
+	glfs_fd_t *glfd = vfs_gluster_fetch_glfd(handle, fsp);
+	if (glfd == NULL) {
+		DBG_ERR("Failed to fetch gluster fd\n");
+		return false;
+	}
 
 	flock.l_type = *ptype;
 	flock.l_whence = SEEK_SET;
@@ -1263,7 +1376,7 @@ static bool vfs_gluster_getlock(struct vfs_handle_struct *handle,
 	flock.l_len = *pcount;
 	flock.l_pid = 0;
 
-	ret = glfs_posix_lock(*(glfs_fd_t **)VFS_FETCH_FSP_EXTENSION(handle, fsp), F_GETLK, &flock);
+	ret = glfs_posix_lock(glfd, F_GETLK, &flock);
 
 	if (ret == -1) {
 		return false;
@@ -1373,7 +1486,13 @@ static ssize_t vfs_gluster_fgetxattr(struct vfs_handle_struct *handle,
 				     files_struct *fsp, const char *name,
 				     void *value, size_t size)
 {
-	return glfs_fgetxattr(*(glfs_fd_t **)VFS_FETCH_FSP_EXTENSION(handle, fsp), name, value, size);
+	glfs_fd_t *glfd = vfs_gluster_fetch_glfd(handle, fsp);
+	if (glfd == NULL) {
+		DBG_ERR("Failed to fetch gluster fd\n");
+		return -1;
+	}
+
+	return glfs_fgetxattr(glfd, name, value, size);
 }
 
 static ssize_t vfs_gluster_listxattr(struct vfs_handle_struct *handle,
@@ -1388,7 +1507,13 @@ static ssize_t vfs_gluster_flistxattr(struct vfs_handle_struct *handle,
 				      files_struct *fsp, char *list,
 				      size_t size)
 {
-	return glfs_flistxattr(*(glfs_fd_t **)VFS_FETCH_FSP_EXTENSION(handle, fsp), list, size);
+	glfs_fd_t *glfd = vfs_gluster_fetch_glfd(handle, fsp);
+	if (glfd == NULL) {
+		DBG_ERR("Failed to fetch gluster fd\n");
+		return -1;
+	}
+
+	return glfs_flistxattr(glfd, list, size);
 }
 
 static int vfs_gluster_removexattr(struct vfs_handle_struct *handle,
@@ -1401,7 +1526,13 @@ static int vfs_gluster_removexattr(struct vfs_handle_struct *handle,
 static int vfs_gluster_fremovexattr(struct vfs_handle_struct *handle,
 				    files_struct *fsp, const char *name)
 {
-	return glfs_fremovexattr(*(glfs_fd_t **)VFS_FETCH_FSP_EXTENSION(handle, fsp), name);
+	glfs_fd_t *glfd = vfs_gluster_fetch_glfd(handle, fsp);
+	if (glfd == NULL) {
+		DBG_ERR("Failed to fetch gluster fd\n");
+		return -1;
+	}
+
+	return glfs_fremovexattr(glfd, name);
 }
 
 static int vfs_gluster_setxattr(struct vfs_handle_struct *handle,
@@ -1416,8 +1547,13 @@ static int vfs_gluster_fsetxattr(struct vfs_handle_struct *handle,
 				 files_struct *fsp, const char *name,
 				 const void *value, size_t size, int flags)
 {
-	return glfs_fsetxattr(*(glfs_fd_t **)VFS_FETCH_FSP_EXTENSION(handle, fsp), name, value, size,
-			      flags);
+	glfs_fd_t *glfd = vfs_gluster_fetch_glfd(handle, fsp);
+	if (glfd == NULL) {
+		DBG_ERR("Failed to fetch gluster fd\n");
+		return -1;
+	}
+
+	return glfs_fsetxattr(glfd, name, value, size, flags);
 }
 
 /* AIO Operations */