From 39db09af1de261ef3b80ce354e8b1b89a599fd40 Mon Sep 17 00:00:00 2001 From: Amar Tumballi Date: Wed, 5 Sep 2018 19:03:08 +0530 Subject: 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 --- xlators/storage/posix/src/posix-inode-fd-ops.c | 33 ++++++++++++++++++++++++++ 1 file changed, 33 insertions(+) diff --git a/xlators/storage/posix/src/posix-inode-fd-ops.c b/xlators/storage/posix/src/posix-inode-fd-ops.c index edd3fc1db3f..81569779fd2 100644 --- a/xlators/storage/posix/src/posix-inode-fd-ops.c +++ b/xlators/storage/posix/src/posix-inode-fd-ops.c @@ -1375,6 +1375,17 @@ 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; + } + if (flags & O_CREAT) DISK_SPACE_CHECK_AND_GOTO (frame, priv, xdata, op_ret, op_errno, out); @@ -1471,6 +1482,17 @@ 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, @@ -1740,6 +1762,17 @@ posix_writev (call_frame_t *frame, xlator_t *this, fd_t *fd, VALIDATE_OR_GOTO (priv, out); DISK_SPACE_CHECK_AND_GOTO (frame, priv, xdata, op_ret, op_errno, 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, -- cgit