ecryptfs-add-passphrase crashes with "Segmentation fault" message if ~/.ecryptfsrc file exists

Bug Description

This happens on ecryptfs-utils binaries that I've built from revision 438.

* Steps to reproduce:

$ cat 'salt=0011223344556677' > ~/.ecryptfsrc
$ ecryptfs-add-passphrase
Passphrase: [ insert random passphrase ]
Segmentation fault

It looks like it's caused by dereferencing a null pointer at src/libecryptfs/key_management.c:694 .

-- Begin patch --------
=== modified file 'src/libecryptfs/key_management.c'
--- src/libecryptfs/key_management.c 2009年07月21日 21:27:10 +0000
+++ src/libecryptfs/key_management.c 2009年08月05日 20:09:03 +0000
@@ -689,7 +689,7 @@
}
goto out;
}
- nvp = &nvp_list_head;
+ nvp = nvp_list_head.next;
while (nvp) {
if (strcmp(nvp->name, "salt") == 0) {
int valsize;
-- End patch --------

When parsing ~/.ecryptfsrc file, a list of ecryptfs_name_val_pair is created and name, value pairs are set starting from the second list element. the list's head only has the next attribute set, hence the null pointer dereference when calling strcmp(nvp->name, "salt"). Patched to start iterating from nvp_list_head->next, as done elsewhere in the code ( such as in src/libecryptfs/decision_graph.c:get_verbosity ).

Thanks for the patch! Fix committed.

:-Dustin