From 08dc006aac79ee1d1f6a5b7044fc973df7f00ed6 Mon Sep 17 00:00:00 2001 From: Chen Qi Date: Tue, 25 Sep 2018 14:02:01 +0800 Subject: [PATCH 2/7] posix: disable open/read/write on special files In the file system, the responsibility w.r.to the block and char device files is related to only support for 'creating' them (using mknod(2)). Once the device files are created, the read/write syscalls for the specific devices are handled by the device driver registered for the specific major number, and depending on the minor number, it knows where to read from. Hence, we are at risk of reading contents from devices which are handled by the host kernel on server nodes. By disabling open/read/write on the device file, we would be safe with the bypass one can achieve from client side (using gfapi) Fixes: bz#1625096 Change-Id: I48c776b0af1cbd2a5240862826d3d8918601e47f Signed-off-by: Amar Tumballi Upstream-Status: Backport Fix CVE-2018-10923 Modified to suite the old version of glusterfs. Signed-off-by: Chen Qi --- xlators/storage/posix/src/posix.c | 33 +++++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/xlators/storage/posix/src/posix.c b/xlators/storage/posix/src/posix.c index b1a529b..506ae91 100644 --- a/xlators/storage/posix/src/posix.c +++ b/xlators/storage/posix/src/posix.c @@ -3091,6 +3091,17 @@ posix_open (call_frame_t *frame, xlator_t *this, priv = this->private; VALIDATE_OR_GOTO (priv, out); + if (loc->inode && + ((loc->inode->ia_type == IA_IFBLK) || + (loc->inode->ia_type == IA_IFCHR))) { + gf_msg (this->name, GF_LOG_ERROR, EINVAL, + P_MSG_INVALID_ARGUMENT, + "open received on a block/char file (%s)", + uuid_utoa (loc->inode->gfid)); + op_errno = EINVAL; + goto out; + } + MAKE_INODE_HANDLE (real_path, this, loc, &stbuf); if (!real_path) { op_ret = -1; @@ -3180,6 +3191,17 @@ posix_readv (call_frame_t *frame, xlator_t *this, priv = this->private; VALIDATE_OR_GOTO (priv, out); + if (fd->inode && + ((fd->inode->ia_type == IA_IFBLK) || + (fd->inode->ia_type == IA_IFCHR))) { + gf_msg (this->name, GF_LOG_ERROR, EINVAL, + P_MSG_INVALID_ARGUMENT, + "readv received on a block/char file (%s)", + uuid_utoa (fd->inode->gfid)); + op_errno = EINVAL; + goto out; + } + ret = posix_fd_ctx_get (fd, this, &pfd, &op_errno); if (ret < 0) { gf_msg (this->name, GF_LOG_WARNING, op_errno, P_MSG_PFD_NULL, @@ -3415,6 +3437,17 @@ posix_writev (call_frame_t *frame, xlator_t *this, fd_t *fd, VALIDATE_OR_GOTO (priv, out); + if (fd->inode && + ((fd->inode->ia_type == IA_IFBLK) || + (fd->inode->ia_type == IA_IFCHR))) { + gf_msg (this->name, GF_LOG_ERROR, EINVAL, + P_MSG_INVALID_ARGUMENT, + "writev received on a block/char file (%s)", + uuid_utoa (fd->inode->gfid)); + op_errno = EINVAL; + goto out; + } + ret = posix_fd_ctx_get (fd, this, &pfd, &op_errno); if (ret < 0) { gf_msg (this->name, GF_LOG_WARNING, ret, P_MSG_PFD_NULL, -- 2.7.4