[Bug-xorriso] Crash in xorriso with fix

[Eliska Svobodova]

Hi,

we discovered a bug which can cause Segmentation Fault.

It happens when xorriso with parameter -setfacl is given a file with too many users for one file. It is caused by leaving a cursor-pointer inside reallocated memory.

Exploitation:

* run the script (it wil create a directory with test files)

* run command:

xorriso -outdev out.img -map . / -setfacl_list Test_dir/File_with_users

Cause:

When reallocating in xorriso/opts_p_z.c on line 927, the pointer wpt is left on the old position which is now outside allocated memory.

Fix:

Save where in the old memory was wpt and after realloc move it to the same position according to buf pointer.

Next add a function that controls the overrun when sprinting access_acl_text into xorriso->info_text (buffer could be huge). If the printed string was too big to fit into xorriso->info_text, the function adds at the end message that the string was truncated.

test_script
Description: Binary data

libisoburn_invalid_pointer_after_realloc.patch
Description: Text Data