fls segfaults in iso9660_proc_dir.

[adambuchbinder]

To reproduce:

$ unzip segfault.zip
Archive:  segfault.zip
  inflating: segfault.img
$ fls segfault.img
Segmentation fault

This bug was found using american fuzzy lop and input files ultimately from files.fuzzing-project.org.

Backtrace:

#0  iso9660_proc_dir (a_dir_addr=<optimized out>, a_addr=0, a_length=8, 
    buf=0x7d2d40 "\353<\220mkfs.\b)H\367\377\177", a_fs_dir=0x7d03c0, 
    a_fs=0x7ced10) at iso9660_dent.c:185
#1  iso9660_dir_open_meta (a_fs=0x7ced10, a_fs_dir=<optimized out>, a_addr=0)
    at iso9660_dent.c:292
#2  0x000000000041f020 in tsk_fs_dir_open_meta (a_fs=<optimized out>, 
    a_addr=<optimized out>) at fs_dir.c:290
#3  0x000000000041f511 in tsk_fs_dir_walk_lcl (a_fs=a_fs@entry=0x7ced10, 
    a_dinfo=a_dinfo@entry=0x7fffffffc530, a_addr=a_addr@entry=0, 
    a_flags=a_flags@entry=(TSK_FS_DIR_WALK_FLAG_ALLOC | TSK_FS_DIR_WALK_FLAG_UNALLOC), a_action=a_action@entry=0x418a10 <print_dent_act>, 
    a_ptr=a_ptr@entry=0x7fffffffd9a0) at fs_dir.c:556
#4  0x0000000000421f39 in tsk_fs_dir_walk (a_fs=0x7ced10, a_addr=0, 
    a_flags=<optimized out>, a_action=0x418a10 <print_dent_act>, 
    a_ptr=0x7fffffffd9a0) at fs_dir.c:817
#5  0x00000000004244e9 in tsk_fs_dir_walk (a_fs=<optimized out>, 
    a_addr=<optimized out>, a_flags=<optimized out>, 
    a_action=a_action@entry=0x418a10 <print_dent_act>, 
    a_ptr=a_ptr@entry=0x7fffffffd9a0) at fs_dir.c:841
#6  0x000000000041a8ae in tsk_fs_fls (fs=<optimized out>, 
    lclflags=<optimized out>, inode=<optimized out>, flags=<optimized out>, 
    tpre=<optimized out>, skew=<optimized out>) at fls_lib.c:262
#7  0x000000000040999f in main (argc=<optimized out>, argv1=<optimized out>)
    at fls.cpp:308

Input: segfault.zip