Description of problem:
Segfault of sshfs mount.

Version-Release number of selected component (if applicable):
fuse-sshfs-2.5-1.el7.x86_64 and earlier.

How reproducible:
Sometimes. Difficult.

Steps to Reproduce:
1. Mount sshfs mount
2. Transfer data

Actual results:
Data transferred.


Expected results:
Segfault.

Additional info:
Upstream developer analysis:
https://github.com/libfuse/sshfs/issues/7#issuecomment-314758425

My own valgrind-memcheck result:

==19702== Invalid read of size 4
==19702==    at 0x114AE6: sftp_readdir_async (sshfs.c:2092)
==19702==    by 0x114AE6: sshfs_getdir (sshfs.c:2157)
==19702==    by 0x1157F1: cache_getdir (cache.c:327)                                                                                                                                                                                                                                                                     
==19702==    by 0x4E42972: fuse_fs_readdir (fuse.c:2014)                                                                                                                                                                                                                                                                 
==19702==    by 0x4E42AAA: readdir_fill (fuse.c:3460)                                                                                                                                                                                                                                                                    
==19702==    by 0x4E42AAA: fuse_lib_readdir (fuse.c:3486)                                                                                                                                                                                                                                                                
==19702==    by 0x4E496A5: do_readdir (fuse_lowlevel.c:1389)                                                                                                                                                                                                                                                             
==19702==    by 0x4E4ABDA: fuse_ll_process_buf (fuse_lowlevel.c:2441)                                                                                                                                                                                                                                                    
==19702==    by 0x4E47470: fuse_do_work (fuse_loop_mt.c:117)                                                                                                                                                                                                                                                             
==19702==    by 0x55B2DC4: start_thread (pthread_create.c:308)                                                                                                                                                                                                                                                           
==19702==    by 0x58BE76C: clone (clone.S:113)                                                                                                                                                                                                                                                                           
==19702==  Address 0x7e4c4c0 is 0 bytes inside a block of size 136 free'd                                                                                                                                                                                                                                                
==19702==    at 0x4C29CDD: free (vg_replace_malloc.c:530)                                                                                                                                                                                                                                                                
==19702==    by 0x52C341D: g_free (gmem.c:189)                                                                                                                                                                                                                                                                           
==19702==    by 0x10E055: process_one_request (sshfs.c:1384)                                                                                                                                                                                                                                                             
==19702==    by 0x10E055: process_requests (sshfs.c:1414)                                                                                                                                                                                                                                                                
==19702==    by 0x55B2DC4: start_thread (pthread_create.c:308)                                                                                                                                                                                                                                                           
==19702==    by 0x58BE76C: clone (clone.S:113)                                                                                                                                                                                                                                                                           
==19702==  Block was alloc'd at                                                                                                                                                                                                                                                                                          
==19702==    at 0x4C2A975: calloc (vg_replace_malloc.c:711)                                                                                                                                                                                                                                                              
==19702==    by 0x52C3365: g_malloc0 (gmem.c:124)                                                                                                                                                                                                                                                                        
==19702==    by 0x11027A: sftp_request_send (sshfs.c:1835)                                                                                                                                                                                                                                                               
==19702==    by 0x1149B7: sftp_readdir_send (sshfs.c:2039)                                                                                                                                                                                                                                                               
==19702==    by 0x1149B7: sftp_readdir_async (sshfs.c:2067)                                                                                                                                                                                                                                                              
==19702==    by 0x1149B7: sshfs_getdir (sshfs.c:2157)                                                                                                                                                                                                                                                                    
==19702==    by 0x1157F1: cache_getdir (cache.c:327)                                                                                                                                                                                                                                                                     
==19702==    by 0x4E42972: fuse_fs_readdir (fuse.c:2014)                                                                                                                                                                                                                                                                 
==19702==    by 0x4E42AAA: readdir_fill (fuse.c:3460)                                                                                                                                                                                                                                                                    
==19702==    by 0x4E42AAA: fuse_lib_readdir (fuse.c:3486)                                                                                                                                                                                                                                                                
==19702==    by 0x4E496A5: do_readdir (fuse_lowlevel.c:1389)                                                                                                                                                                                                                                                             
==19702==    by 0x4E4ABDA: fuse_ll_process_buf (fuse_lowlevel.c:2441)                                                                                                                                                                                                                                                    
==19702==    by 0x4E47470: fuse_do_work (fuse_loop_mt.c:117)                                                                                                                                                                                                                                                             
==19702==    by 0x55B2DC4: start_thread (pthread_create.c:308)                                                                                                                                                                                                                                                           
==19702==    by 0x58BE76C: clone (clone.S:113)