pam_succeed_if: prevent logging unknown user names in plaintext#985
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lzwind wants to merge 1 commit into
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pam_succeed_if: prevent logging unknown user names in plaintext#985lzwind wants to merge 1 commit into
lzwind wants to merge 1 commit into
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When a user accidentally types their password at the username prompt, pam_succeed_if logs the password in plaintext via pam_syslog. This happens because evaluate_ingroup, evaluate_notingroup, evaluate_innetgr, and evaluate_notinnetgr return PAM_AUTH_ERR or PAM_SUCCESS for non-existent users instead of PAM_USER_UNKNOWN, bypassing the existing log guard. Add pam_modutil_getpwnam() checks in these four functions to return PAM_USER_UNKNOWN when the user does not exist, so the existing logging guard (ret != PAM_USER_UNKNOWN) correctly suppresses the output. Fixes: linux-pam#559
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Summary
pam_succeed_iflogs the password in plaintext viapam_syslog. This happens becauseevaluate_ingroup,evaluate_notingroup,evaluate_innetgr, andevaluate_notinnetgrreturnPAM_AUTH_ERRorPAM_SUCCESSfor non-existent users instead ofPAM_USER_UNKNOWN, bypassing the existing log guard (ret != PAM_USER_UNKNOWN).pam_modutil_getpwnam()checks in these four functions to returnPAM_USER_UNKNOWNwhen the user does not exist, so the existing logging guard correctly suppresses the output.Fixes: #559
Test plan
pam_succeed_if.so user ingroup <group>, it no longer appears in logsingroup,notingroup,innetgr,notinnetgrqualifiers all behave correctly