pam_limits.8 4.4 KB

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  1. '\" t
  2. .\" Title: pam_limits
  3. .\" Author: [see the "AUTHORS" section]
  4. .\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
  5. .\" Date: 09/03/2021
  6. .\" Manual: Linux-PAM Manual
  7. .\" Source: Linux-PAM Manual
  8. .\" Language: English
  9. .\"
  10. .TH "PAM_LIMITS" "8" "09/03/2021" "Linux-PAM Manual" "Linux-PAM Manual"
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  15. .\" http://bugs.debian.org/507673
  16. .\" http://lists.gnu.org/archive/html/groff/2009-02/msg00013.html
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  24. .nh
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  28. .\" * MAIN CONTENT STARTS HERE *
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  30. .SH "NAME"
  31. pam_limits \- PAM module to limit resources
  32. .SH "SYNOPSIS"
  33. .HP \w'\fBpam_limits\&.so\fR\ 'u
  34. \fBpam_limits\&.so\fR [conf=\fI/path/to/limits\&.conf\fR] [debug] [set_all] [utmp_early] [noaudit]
  35. .SH "DESCRIPTION"
  36. .PP
  37. The pam_limits PAM module sets limits on the system resources that can be obtained in a user\-session\&. Users of
  38. \fIuid=0\fR
  39. are affected by this limits, too\&.
  40. .PP
  41. By default limits are taken from the
  42. /etc/security/limits\&.conf
  43. config file\&. Then individual *\&.conf files from the
  44. /etc/security/limits\&.d/
  45. directory are read\&. The files are parsed one after another in the order of "C" locale\&. The effect of the individual files is the same as if all the files were concatenated together in the order of parsing\&. If a config file is explicitly specified with a module option then the files in the above directory are not parsed\&.
  46. .PP
  47. The module must not be called by a multithreaded application\&.
  48. .PP
  49. If Linux PAM is compiled with audit support the module will report when it denies access based on limit of maximum number of concurrent login sessions\&.
  50. .SH "OPTIONS"
  51. .PP
  52. \fBconf=\fR\fB\fI/path/to/limits\&.conf\fR\fR
  53. .RS 4
  54. Indicate an alternative limits\&.conf style configuration file to override the default\&.
  55. .RE
  56. .PP
  57. \fBdebug\fR
  58. .RS 4
  59. Print debug information\&.
  60. .RE
  61. .PP
  62. \fBset_all\fR
  63. .RS 4
  64. Set the limits for which no value is specified in the configuration file to the one from the process with the PID 1\&. Please note that if the init process is systemd these limits will not be the kernel default limits and this option should not be used\&.
  65. .RE
  66. .PP
  67. \fButmp_early\fR
  68. .RS 4
  69. Some broken applications actually allocate a utmp entry for the user before the user is admitted to the system\&. If some of the services you are configuring PAM for do this, you can selectively use this module argument to compensate for this behavior and at the same time maintain system\-wide consistency with a single limits\&.conf file\&.
  70. .RE
  71. .PP
  72. \fBnoaudit\fR
  73. .RS 4
  74. Do not report exceeded maximum logins count to the audit subsystem\&.
  75. .RE
  76. .SH "MODULE TYPES PROVIDED"
  77. .PP
  78. Only the
  79. \fBsession\fR
  80. module type is provided\&.
  81. .SH "RETURN VALUES"
  82. .PP
  83. PAM_ABORT
  84. .RS 4
  85. Cannot get current limits\&.
  86. .RE
  87. .PP
  88. PAM_IGNORE
  89. .RS 4
  90. No limits found for this user\&.
  91. .RE
  92. .PP
  93. PAM_PERM_DENIED
  94. .RS 4
  95. New limits could not be set\&.
  96. .RE
  97. .PP
  98. PAM_SERVICE_ERR
  99. .RS 4
  100. Cannot read config file\&.
  101. .RE
  102. .PP
  103. PAM_SESSION_ERR
  104. .RS 4
  105. Error recovering account name\&.
  106. .RE
  107. .PP
  108. PAM_SUCCESS
  109. .RS 4
  110. Limits were changed\&.
  111. .RE
  112. .PP
  113. PAM_USER_UNKNOWN
  114. .RS 4
  115. The user is not known to the system\&.
  116. .RE
  117. .SH "FILES"
  118. .PP
  119. /etc/security/limits\&.conf
  120. .RS 4
  121. Default configuration file
  122. .RE
  123. .SH "EXAMPLES"
  124. .PP
  125. For the services you need resources limits (login for example) put a the following line in
  126. /etc/pam\&.d/login
  127. as the last line for that service (usually after the pam_unix session line):
  128. .sp
  129. .if n \{\
  130. .RS 4
  131. .\}
  132. .nf
  133. #%PAM\-1\&.0
  134. #
  135. # Resource limits imposed on login sessions via pam_limits
  136. #
  137. session required pam_limits\&.so
  138. .fi
  139. .if n \{\
  140. .RE
  141. .\}
  142. .PP
  143. Replace "login" for each service you are using this module\&.
  144. .SH "SEE ALSO"
  145. .PP
  146. \fBlimits.conf\fR(5),
  147. \fBpam.d\fR(5),
  148. \fBpam\fR(8)\&.
  149. .SH "AUTHORS"
  150. .PP
  151. pam_limits was initially written by Cristian Gafton <gafton@redhat\&.com>