Red Hat Bugzilla – Bug 164991
CAN-2005-2099 Destruction of failed keyring oopses
Last modified: 2007-11-30 17:07:19 EST
+++ This bug was initially created as a clone of Bug #164989 +++
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Description of problem:
This was found on RHEL-4-pre-U2 and patched there before U2 was frozen.
If a keyring is not fully instantiated when it is destroyed, the kernel will
oops when it tries to unlink the keyring name from the name list.
The problem occurs in three stages:
(1) The key allocator initialises the type-specific data to all zeroes. In
the case of a keyring, this will become a link in the keyring name list
when the keyring is instantiated.
(2) If a user (any user) attempts to add a keyring with anything other than
an empty payload, the keyring instantiation function will fail with an
error and won't add the keyring to the name list.
(3) The keyring's destructor then sees that the keyring has a description
(name) and tries to remove the keyring from the name list, which oopses
because the link pointers are both zero.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1.keyctl add keyring a a @p
Actual Results: It oopses on a NULL pointer dereference.
Expected Results: It should get EINVAL.
This bug is already fixed in RHEL-4 U2.
We sent this to email@example.com on 20050803 and it was fixed upstream 20050804
An advisory has been issued which should help the problem
described in this bug report. This report is therefore being
closed with a resolution of ERRATA. For more information
on the solution and/or where to find the updated files,
please follow the link below. You may reopen this bug report
if the solution does not work for you.