Public bug reported:
Introducing valid usernames with trailing newline characters triggers
the removal of valid LDB cache entries
Reproducer:
1. Request a valid user and confirm it's cached:
ubuntu@ubuntu:~⟫ sudo sss_cache -E; getent passwd 'ad1'
ad1:*:1500:1500:ad1:/home/ad:/bin/bash
ubuntu@ubuntu:~⟫ sudo ldbsearch -H /var/lib/sss/db/cache_UBUNTU.TEST.ldb -b
name=ad1,cn=users,cn=UBUNTU.TEST,cn=sysdb | grep entries
asq: Unable to register control with rootdse!
# 1 entries
2. Request an invalid username:
ubuntu@ubuntu:~⟫ sudo sss_cache -E; getent passwd 'ad1
'
3. Confirm the cache entry has disappeared:
ubuntu@ubuntu:~⟫ sudo ldbsearch -H /var/lib/sss/db/cache_UBUNTU.TEST.ldb -b
name=ad1,cn=users,cn=UBUNTU.TEST,cn=sysdb | grep entries
asq: Unable to register control with rootdse!
# 0 entries
This is an excerpt from the logs of the request with the newline char:
(Tue Feb 28 16:07:40 2017) [sssd[be[UBUNTU.TEST]]] [be_get_account_info]
(0x0200): Got request for [0x1001][FAST BE_REQ_USER][1][name=ad1
]
(Tue Feb 28 16:08:33 2017) [sssd[be[UBUNTU.TEST]]] [sdap_get_generic_ext_step]
(0x0400): calling ldap_search_ext with [(&(sAMAccountName=ad1
)(objectclass=user)(sAMAccountName=*)(&(uidNumber=*)(!(uidNumber=0))))][CN=Users,DC=ubuntu,DC=test].
(Tue Feb 28 16:08:33 2017) [sssd[be[UBUNTU.TEST]]] [sdap_get_users_done]
(0x0040): Failed to retrieve users
(Tue Feb 28 16:08:33 2017) [sssd[nss]] [sss_ncache_set_str] (0x0400): Adding
[NCE/USER/UBUNTU.TEST/ad1
] to negative cache
(Tue Feb 28 16:08:33 2017) [sssd[nss]] [nss_cmd_getpwnam_search] (0x0040): No
results for getpwnam call
At this point, the ldb entry removal request for ad1 (without \n) takes
place via sysdb_delete_user.
Adding '\n' to the character list in sss_filter_sanitize_ex() seems to fix this
issue.
Upstream bug: https://pagure.io/SSSD/sssd/issue/3317
** Affects: sssd (Ubuntu)
Importance: Medium
Assignee: Victor Tapia (vtapia)
Status: New
** Tags: sts
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https://bugs.launchpad.net/bugs/1669712
Title:
Newline characters (\n) must be sanitized before LDAP requests take
place.
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