A race condition exists when parallel code accesses shared data without proper coordination. An attack that uses a race-condition weakness takes advantage of the unsafe data access to manipulate how one of the parallel sections of code reacts. Even though each process runs as intended, the outcome is unexpected. For example, consider a bank service that depends on an encryption key that it reads from a known location. An independent cryptography service is responsible for generating the key and placing it where the bank is expected to read it in a timely manner. If the bank and cryptography services do not coordinate with each other, then the bank may read a blank encryption key before cryptography writes the key to the location. This can effectively turn off all encryption for the bank without either service, or the administrator, knowing that something has gone wrong.
The highlighted line of code below is the trigger point of this particular Red Hat Enterprise Linux 7 race weakness.
* fuse_reply_err * * @param req request handle * @param ino the inode number * @param attr the attributes * @param to_set bit mask of attributes which should be set * @param fi file information, or NULL * * Changed in version 2.5: * file information filled in for ftruncate */ void (*setattr) (fuse_req_t req, fuse_ino_t ino, struct stat *attr, int to_set, struct fuse_file_info *fi); /** * Read symbolic link * * Valid replies: * fuse_reply_readlink * fuse_reply_err * * @param req request handle * @param ino the inode number */ void (*readlink) (fuse_req_t req, fuse_ino_t ino); /** * Create file node * * Create a regular file, character device, block device, fifo or * socket node. * * Valid replies: * fuse_reply_entry * fuse_reply_err * * @param req request handle * @param parent inode number of the parent directory * @param name to create * @param mode file type and mode with which to create the new file * @param rdev the device number (only valid if created file is a device) */ void (*mknod) (fuse_req_t req, fuse_ino_t parent, const char *name, mode_t mode, dev_t rdev); /** * Create a directory * * Valid replies: * fuse_reply_entry