1SUDO(8) BSD System Manager's Manual SUDO(8)
2
4 sudo, sudoedit — execute a command as another user
5
7 sudo -h | -K | -k | -V
8 sudo -v [-ABkNnS] [-g group] [-h host] [-p prompt] [-u user]
9 sudo -l [-ABkNnS] [-g group] [-h host] [-p prompt] [-U user] [-u user]
10 [command [arg ...]]
11 sudo [-ABbEHnPS] [-C num] [-D directory] [-g group] [-h host] [-p prompt]
12 [-R directory] [-r role] [-t type] [-T timeout] [-u user]
13 [VAR=value] [-i | -s] [command [arg ...]]
14 sudoedit [-ABkNnS] [-C num] [-D directory] [-g group] [-h host]
15 [-p prompt] [-R directory] [-r role] [-t type] [-T timeout]
16 [-u user] file ...
17
19 sudo allows a permitted user to execute a command as the superuser or an‐
20 other user, as specified by the security policy. The invoking user's
21 real (not effective) user-ID is used to determine the user name with
22 which to query the security policy.
23 sudo supports a plugin architecture for security policies, auditing, and
25 input/output logging. Third parties can develop and distribute their own
26 plugins to work seamlessly with the sudo front-end. The default security
27 policy is sudoers, which is configured via the file /etc/sudoers, or via
28 LDAP. See the Plugins section for more information.
29 The security policy determines what privileges, if any, a user has to run
31 sudo. The policy may require that users authenticate themselves with a
32 password or another authentication mechanism. If authentication is re‐
33 quired, sudo will exit if the user's password is not entered within a
34 configurable time limit. This limit is policy-specific; the default
35 password prompt timeout for the sudoers security policy is 5 minutes.
36 Security policies may support credential caching to allow the user to run
38 sudo again for a period of time without requiring authentication. By de‐
39 fault, the sudoers policy caches credentials on a per-terminal basis for
40 5 minutes. See the timestamp_type and timestamp_timeout options in
41 sudoers(5) for more information. By running sudo with the -v option, a
42 user can update the cached credentials without running a command.
43 On systems where sudo is the primary method of gaining superuser privi‐
45 leges, it is imperative to avoid syntax errors in the security policy
46 configuration files. For the default security policy, sudoers(5),
47 changes to the configuration files should be made using the visudo(8)
48 utility which will ensure that no syntax errors are introduced.
49 When invoked as sudoedit, the -e option (described below), is implied.
51 Security policies and audit plugins may log successful and failed at‐
53 tempts to run sudo. If an I/O plugin is configured, the running
54 command's input and output may be logged as well.
55 The options are as follows:
57 -A, --askpass
59 Normally, if sudo requires a password, it will read it from the
60 user's terminal. If the -A (askpass) option is specified, a
61 (possibly graphical) helper program is executed to read the
62 user's password and output the password to the standard output.
63 If the SUDO_ASKPASS environment variable is set, it specifies the
64 path to the helper program. Otherwise, if sudo.conf(5) contains
65 a line specifying the askpass program, that value will be used.
66 For example:
67 # Path to askpass helper program
69 Path askpass /usr/X11R6/bin/ssh-askpass
70 If no askpass program is available, sudo will exit with an error.
72 -B, --bell
74 Ring the bell as part of the password prompt when a terminal is
75 present. This option has no effect if an askpass program is
76 used.
77 -b, --background
79 Run the given command in the background. It is not possible to
80 use shell job control to manipulate background processes started
81 by sudo. Most interactive commands will fail to work properly in
82 background mode.
83 -C num, --close-from=num
85 Close all file descriptors greater than or equal to num before
86 executing a command. Values less than three are not permitted.
87 By default, sudo will close all open file descriptors other than
88 standard input, standard output, and standard error when execut‐
89 ing a command. The security policy may restrict the user's abil‐
90 ity to use this option. The sudoers policy only permits use of
91 the -C option when the administrator has enabled the
92 closefrom_override option.
93 -D directory, --chdir=directory
95 Run the command in the specified directory instead of the current
96 working directory. The security policy may return an error if
97 the user does not have permission to specify the working direc‐
98 tory.
99 -E, --preserve-env
101 Indicates to the security policy that the user wishes to preserve
102 their existing environment variables. The security policy may
103 return an error if the user does not have permission to preserve
104 the environment.
105 --preserve-env=list
107 Indicates to the security policy that the user wishes to add the
108 comma-separated list of environment variables to those preserved
109 from the user's environment. The security policy may return an
110 error if the user does not have permission to preserve the envi‐
111 ronment. This option may be specified multiple times.
112 -e, --edit
114 Edit one or more files instead of running a command. In lieu of
115 a path name, the string "sudoedit" is used when consulting the
116 security policy. If the user is authorized by the policy, the
117 following steps are taken:
118 1. Temporary copies are made of the files to be edited with the
120 owner set to the invoking user.
121 2. The editor specified by the policy is run to edit the tempo‐
123 rary files. The sudoers policy uses the SUDO_EDITOR, VISUAL
124 and EDITOR environment variables (in that order). If none
125 of SUDO_EDITOR, VISUAL or EDITOR are set, the first program
126 listed in the editor sudoers(5) option is used.
127 3. If they have been modified, the temporary files are copied
129 back to their original location and the temporary versions
130 are removed.
131 To help prevent the editing of unauthorized files, the following
133 restrictions are enforced unless explicitly allowed by the secu‐
134 rity policy:
135 • Symbolic links may not be edited (version 1.8.15 and higher).
137 • Symbolic links along the path to be edited are not followed
139 when the parent directory is writable by the invoking user
140 unless that user is root (version 1.8.16 and higher).
141 • Files located in a directory that is writable by the invoking
143 user may not be edited unless that user is root (version
144 1.8.16 and higher).
145 Users are never allowed to edit device special files.
147 If the specified file does not exist, it will be created. Unlike
149 most commands run by sudo, the editor is run with the invoking
150 user's environment unmodified. If the temporary file becomes
151 empty after editing, the user will be prompted before it is in‐
152 stalled. If, for some reason, sudo is unable to update a file
153 with its edited version, the user will receive a warning and the
154 edited copy will remain in a temporary file.
155 -g group, --group=group
157 Run the command with the primary group set to group instead of
158 the primary group specified by the target user's password data‐
159 base entry. The group may be either a group name or a numeric
160 group-ID (GID) prefixed with the ‘#’ character (e.g., ‘#0’ for
161 GID 0). When running a command as a GID, many shells require
162 that the ‘#’ be escaped with a backslash (‘\’). If no -u option
163 is specified, the command will be run as the invoking user. In
164 either case, the primary group will be set to group. The sudoers
165 policy permits any of the target user's groups to be specified
166 via the -g option as long as the -P option is not in use.
167 -H, --set-home
169 Request that the security policy set the HOME environment vari‐
170 able to the home directory specified by the target user's pass‐
171 word database entry. Depending on the policy, this may be the
172 default behavior.
173 -h, --help
175 Display a short help message to the standard output and exit.
176 -h host, --host=host
178 Run the command on the specified host if the security policy
179 plugin supports remote commands. The sudoers plugin does not cur‐
180 rently support running remote commands. This may also be used in
181 conjunction with the -l option to list a user's privileges for
182 the remote host.
183 -i, --login
185 Run the shell specified by the target user's password database
186 entry as a login shell. This means that login-specific resource
187 files such as .profile, .bash_profile, or .login will be read by
188 the shell. If a command is specified, it is passed to the shell
189 as a simple command using the -c option. The command and any
190 args are concatenated, separated by spaces, after escaping each
191 character (including white space) with a backslash (‘\’) except
192 for alphanumerics, underscores, hyphens, and dollar signs. If no
193 command is specified, an interactive shell is executed. sudo at‐
194 tempts to change to that user's home directory before running the
195 shell. The command is run with an environment similar to the one
196 a user would receive at log in. Most shells behave differently
197 when a command is specified as compared to an interactive ses‐
198 sion; consult the shell's manual for details. The Command
199 environment section in the sudoers(5) manual documents how the -i
200 option affects the environment in which a command is run when the
201 sudoers policy is in use.
202 -K, --remove-timestamp
204 Similar to the -k option, except that it removes every cached
205 credential for the user, regardless of the terminal or parent
206 process ID. The next time sudo is run, a password must be en‐
207 tered if the security policy requires authentication. It is not
208 possible to use the -K option in conjunction with a command or
209 other option. This option does not require a password. Not all
210 security policies support credential caching.
211 -k, --reset-timestamp
213 When used without a command, invalidates the user's cached cre‐
214 dentials for the current session. The next time sudo is run in
215 the session, a password must be entered if the security policy
216 requires authentication. By default, the sudoers policy uses a
217 separate record in the credential cache for each terminal (or
218 parent process ID if no terminal is present). This prevents the
219 -k option from interfering with sudo commands run in a different
220 terminal session. See the timestamp_type option in sudoers(5)
221 for more information. This option does not require a password,
222 and was added to allow a user to revoke sudo permissions from a
223 .logout file.
224 When used in conjunction with a command or an option that may re‐
226 quire a password, this option will cause sudo to ignore the
227 user's cached credentials. As a result, sudo will prompt for a
228 password (if one is required by the security policy) and will not
229 update the user's cached credentials.
230 Not all security policies support credential caching.
232 -l, --list
234 If no command is specified, list the privileges for the invoking
235 user (or the user specified by the -U option) on the current
236 host. A longer list format is used if this option is specified
237 multiple times and the security policy supports a verbose output
238 format.
239 If a command is specified and is permitted by the security pol‐
241 icy, the fully-qualified path to the command is displayed along
242 with any args. If a command is specified but not allowed by the
243 policy, sudo will exit with a status value of 1.
244 -N, --no-update
246 Do not update the user's cached credentials, even if the user
247 successfully authenticates. Unlike the -k flag, existing cached
248 credentials are used if they are valid. To detect when the
249 user's cached credentials are valid (or when no authentication is
250 required), the following can be used:
251 sudo -Nnv
252 Not all security policies support credential caching.
254 -n, --non-interactive
256 Avoid prompting the user for input of any kind. If a password is
257 required for the command to run, sudo will display an error mes‐
258 sage and exit.
259 -P, --preserve-groups
261 Preserve the invoking user's group vector unaltered. By default,
262 the sudoers policy will initialize the group vector to the list
263 of groups the target user is a member of. The real and effective
264 group-IDs, however, are still set to match the target user.
265 -p prompt, --prompt=prompt
267 Use a custom password prompt with optional escape sequences. The
268 following percent (‘%’) escape sequences are supported by the
269 sudoers policy:
270 %H expanded to the host name including the domain name (only if
272 the machine's host name is fully qualified or the fqdn option
273 is set in sudoers(5))
274 %h expanded to the local host name without the domain name
276 %p expanded to the name of the user whose password is being re‐
278 quested (respects the rootpw, targetpw, and runaspw flags in
279 sudoers(5))
280 %U expanded to the login name of the user the command will be
282 run as (defaults to root unless the -u option is also speci‐
283 fied)
284 %u expanded to the invoking user's login name
286 %% two consecutive ‘%’ characters are collapsed into a single
288 ‘%’ character
289 The custom prompt will override the default prompt specified by
291 either the security policy or the SUDO_PROMPT environment vari‐
292 able. On systems that use PAM, the custom prompt will also over‐
293 ride the prompt specified by a PAM module unless the
294 passprompt_override flag is disabled in sudoers.
295 -R directory, --chroot=directory
297 Change to the specified root directory (see chroot(8)) before
298 running the command. The security policy may return an error if
299 the user does not have permission to specify the root directory.
300 -r role, --role=role
302 Run the command with an SELinux security context that includes
303 the specified role.
304 -S, --stdin
306 Write the prompt to the standard error and read the password from
307 the standard input instead of using the terminal device.
308 -s, --shell
310 Run the shell specified by the SHELL environment variable if it
311 is set or the shell specified by the invoking user's password
312 database entry. If a command is specified, it is passed to the
313 shell as a simple command using the -c option. The command and
314 any args are concatenated, separated by spaces, after escaping
315 each character (including white space) with a backslash (‘\’) ex‐
316 cept for alphanumerics, underscores, hyphens, and dollar signs.
317 If no command is specified, an interactive shell is executed.
318 Most shells behave differently when a command is specified as
319 compared to an interactive session; consult the shell's manual
320 for details.
321 -t type, --type=type
323 Run the command with an SELinux security context that includes
324 the specified type. If no type is specified, the default type is
325 derived from the role.
326 -U user, --other-user=user
328 Used in conjunction with the -l option to list the privileges for
329 user instead of for the invoking user. The security policy may
330 restrict listing other users' privileges. When using the sudoers
331 policy, the -U option is restricted to the root user and users
332 with either the “list” priviege for the specified user or the
333 ability to run any command as root or user on the current host.
334 -T timeout, --command-timeout=timeout
336 Used to set a timeout for the command. If the timeout expires
337 before the command has exited, the command will be terminated.
338 The security policy may restrict the user's ability to set time‐
339 outs. The sudoers policy requires that user-specified timeouts
340 be explicitly enabled.
341 -u user, --user=user
343 Run the command as a user other than the default target user
344 (usually root). The user may be either a user name or a numeric
345 user-ID (UID) prefixed with the ‘#’ character (e.g., ‘#0’ for UID
346 0). When running commands as a UID, many shells require that the
347 ‘#’ be escaped with a backslash (‘\’). Some security policies
348 may restrict UIDs to those listed in the password database. The
349 sudoers policy allows UIDs that are not in the password database
350 as long as the targetpw option is not set. Other security poli‐
351 cies may not support this.
352 -V, --version
354 Print the sudo version string as well as the version string of
355 any configured plugins. If the invoking user is already root,
356 the -V option will display the options passed to configure when
357 sudo was built; plugins may display additional information such
358 as default options.
359 -v, --validate
361 Update the user's cached credentials, authenticating the user if
362 necessary. For the sudoers plugin, this extends the sudo timeout
363 for another 5 minutes by default, but does not run a command.
364 Not all security policies support cached credentials.
365 -- The -- is used to delimit the end of the sudo options. Subse‐
367 quent options are passed to the command.
368 Options that take a value may only be specified once unless otherwise in‐
370 dicated in the description. This is to help guard against problems
371 caused by poorly written scripts that invoke sudo with user-controlled
372 input.
373 Environment variables to be set for the command may also be passed as op‐
375 tions to sudo in the form VAR=value, for example
376 LD_LIBRARY_PATH=/usr/local/pkg/lib. Environment variables may be subject
377 to restrictions imposed by the security policy plugin. The sudoers pol‐
378 icy subjects environment variables passed as options to the same restric‐
379 tions as existing environment variables with one important difference.
380 If the setenv option is set in sudoers, the command to be run has the
381 SETENV tag set or the command matched is ALL, the user may set variables
382 that would otherwise be forbidden. See sudoers(5) for more information.
383
385 When sudo executes a command, the security policy specifies the execution
386 environment for the command. Typically, the real and effective user and
387 group and IDs are set to match those of the target user, as specified in
388 the password database, and the group vector is initialized based on the
389 group database (unless the -P option was specified).
390 The following parameters may be specified by security policy:
392 • real and effective user-ID
394 • real and effective group-ID
396 • supplementary group-IDs
398 • the environment list
400 • current working directory
402 • file creation mode mask (umask)
404 • SELinux role and type
406 • scheduling priority (aka nice value)
408 Process model
410 There are two distinct ways sudo can run a command.
411 If an I/O logging plugin is configured to log terminal I/O, or if the se‐
413 curity policy explicitly requests it, a new pseudo-terminal (“pty”) is
414 allocated and fork(2) is used to create a second sudo process, referred
415 to as the monitor. The monitor creates a new terminal session with it‐
416 self as the leader and the pty as its controlling terminal, calls fork(2)
417 again, sets up the execution environment as described above, and then
418 uses the execve(2) system call to run the command in the child process.
419 The monitor exists to relay job control signals between the user's termi‐
420 nal and the pty the command is being run in. This makes it possible to
421 suspend and resume the command normally. Without the monitor, the
422 command would be in what POSIX terms an “orphaned process group” and it
423 would not receive any job control signals from the kernel. When the
424 command exits or is terminated by a signal, the monitor passes the
425 command's exit status to the main sudo process and exits. After receiv‐
426 ing the command's exit status, the main sudo process passes the command's
427 exit status to the security policy's close function, as well as the close
428 function of any configured audit plugin, and exits. This mode is the de‐
429 fault for sudo versions 1.9.14 and above when using the sudoers policy.
430 If no pty is used, sudo calls fork(2), sets up the execution environment
432 as described above, and uses the execve(2) system call to run the command
433 in the child process. The main sudo process waits until the command has
434 completed, then passes the command's exit status to the security policy's
435 close function, as well as the close function of any configured audit
436 plugins, and exits. As a special case, if the policy plugin does not de‐
437 fine a close function, sudo will execute the command directly instead of
438 calling fork(2) first. The sudoers policy plugin will only define a
439 close function when I/O logging is enabled, a pty is required, an SELinux
440 role is specified, the command has an associated timeout, or the
441 pam_session or pam_setcred options are enabled. Both pam_session and
442 pam_setcred are enabled by default on systems using PAM. This mode is
443 the default for sudo versions prior to 1.9.14 when using the sudoers pol‐
444 icy.
445 On systems that use PAM, the security policy's close function is respon‐
447 sible for closing the PAM session. It may also log the command's exit
448 status.
449 Signal handling
451 When the command is run as a child of the sudo process, sudo will relay
452 signals it receives to the command. The SIGINT and SIGQUIT signals are
453 only relayed when the command is being run in a new pty or when the sig‐
454 nal was sent by a user process, not the kernel. This prevents the
455 command from receiving SIGINT twice each time the user enters control-C.
456 Some signals, such as SIGSTOP and SIGKILL, cannot be caught and thus will
457 not be relayed to the command. As a general rule, SIGTSTP should be used
458 instead of SIGSTOP when you wish to suspend a command being run by sudo.
459 As a special case, sudo will not relay signals that were sent by the
461 command it is running. This prevents the command from accidentally
462 killing itself. On some systems, the reboot(8) utility sends SIGTERM to
463 all non-system processes other than itself before rebooting the system.
464 This prevents sudo from relaying the SIGTERM signal it received back to
465 reboot(8), which might then exit before the system was actually rebooted,
466 leaving it in a half-dead state similar to single user mode. Note, how‐
467 ever, that this check only applies to the command run by sudo and not any
468 other processes that the command may create. As a result, running a
469 script that calls reboot(8) or shutdown(8) via sudo may cause the system
470 to end up in this undefined state unless the reboot(8) or shutdown(8) are
471 run using the exec() family of functions instead of system() (which in‐
472 terposes a shell between the command and the calling process).
473 Plugins
475 Plugins may be specified via Plugin directives in the sudo.conf(5) file.
476 They may be loaded as dynamic shared objects (on systems that support
477 them), or compiled directly into the sudo binary. If no sudo.conf(5)
478 file is present, or if it doesn't contain any Plugin lines, sudo will use
479 sudoers(5) for the policy, auditing, and I/O logging plugins. See the
480 sudo.conf(5) manual for details of the /etc/sudo.conf file and the
481 sudo_plugin(5) manual for more information about the sudo plugin archi‐
482 tecture.
483
485 Upon successful execution of a command, the exit status from sudo will be
486 the exit status of the program that was executed. If the command termi‐
487 nated due to receipt of a signal, sudo will send itself the same signal
488 that terminated the command.
489 If the -l option was specified without a command, sudo will exit with a
491 value of 0 if the user is allowed to run sudo and they authenticated suc‐
492 cessfully (as required by the security policy). If a command is speci‐
493 fied with the -l option, the exit value will only be 0 if the command is
494 permitted by the security policy, otherwise it will be 1.
495 If there is an authentication failure, a configuration/permission prob‐
497 lem, or if the given command cannot be executed, sudo exits with a value
498 of 1. In the latter case, the error string is printed to the standard
499 error. If sudo cannot stat(2) one or more entries in the user's PATH, an
500 error is printed to the standard error. (If the directory does not exist
501 or if it is not really a directory, the entry is ignored and no error is
502 printed.) This should not happen under normal circumstances. The most
503 common reason for stat(2) to return “permission denied” is if you are
504 running an automounter and one of the directories in your PATH is on a
505 machine that is currently unreachable.
506
508 sudo tries to be safe when executing external commands.
509 To prevent command spoofing, sudo checks "." and "" (both denoting cur‐
511 rent directory) last when searching for a command in the user's PATH (if
512 one or both are in the PATH). Depending on the security policy, the
513 user's PATH environment variable may be modified, replaced, or passed un‐
514 changed to the program that sudo executes.
515 Users should never be granted sudo privileges to execute files that are
517 writable by the user or that reside in a directory that is writable by
518 the user. If the user can modify or replace the command there is no way
519 to limit what additional commands they can run.
520 By default, sudo will only log the command it explicitly runs. If a user
522 runs a command such as ‘sudo su’ or ‘sudo sh’, subsequent commands run
523 from that shell are not subject to sudo's security policy. The same is
524 true for commands that offer shell escapes (including most editors). If
525 I/O logging is enabled, subsequent commands will have their input and/or
526 output logged, but there will not be traditional logs for those commands.
527 Because of this, care must be taken when giving users access to commands
528 via sudo to verify that the command does not inadvertently give the user
529 an effective root shell. For information on ways to address this, see
530 the Preventing shell escapes section in sudoers(5).
531 To prevent the disclosure of potentially sensitive information, sudo dis‐
533 ables core dumps by default while it is executing (they are re-enabled
534 for the command that is run). This historical practice dates from a time
535 when most operating systems allowed set-user-ID processes to dump core by
536 default. To aid in debugging sudo crashes, you may wish to re-enable
537 core dumps by setting “disable_coredump” to false in the sudo.conf(5)
538 file as follows:
539 Set disable_coredump false
541 See the sudo.conf(5) manual for more information.
543
545 sudo utilizes the following environment variables. The security policy
546 has control over the actual content of the command's environment.
547 EDITOR Default editor to use in -e (sudoedit) mode if neither
549 SUDO_EDITOR nor VISUAL is set.
550 MAIL Set to the mail spool of the target user when the -i op‐
552 tion is specified, or when env_reset is enabled in
553 sudoers (unless MAIL is present in the env_keep list).
554 HOME Set to the home directory of the target user when the -i
556 or -H options are specified, when the -s option is spec‐
557 ified and set_home is set in sudoers, when
558 always_set_home is enabled in sudoers, or when env_reset
559 is enabled in sudoers and HOME is not present in the
560 env_keep list.
561 LOGNAME Set to the login name of the target user when the -i op‐
563 tion is specified, when the set_logname option is en‐
564 abled in sudoers, or when the env_reset option is en‐
565 abled in sudoers (unless LOGNAME is present in the
566 env_keep list).
567 PATH May be overridden by the security policy.
569 SHELL Used to determine shell to run with -s option.
571 SUDO_ASKPASS Specifies the path to a helper program used to read the
573 password if no terminal is available or if the -A option
574 is specified.
575 SUDO_COMMAND Set to the command run by sudo, including any args. The
577 args are truncated at 4096 characters to prevent a po‐
578 tential execution error.
579 SUDO_EDITOR Default editor to use in -e (sudoedit) mode.
581 SUDO_GID Set to the group-ID of the user who invoked sudo.
583 SUDO_PROMPT Used as the default password prompt unless the -p option
585 was specified.
586 SUDO_PS1 If set, PS1 will be set to its value for the program be‐
588 ing run.
589 SUDO_UID Set to the user-ID of the user who invoked sudo.
591 SUDO_USER Set to the login name of the user who invoked sudo.
593 USER Set to the same value as LOGNAME, described above.
595 VISUAL Default editor to use in -e (sudoedit) mode if
597 SUDO_EDITOR is not set.
598
600 /etc/sudo.conf sudo front-end configuration
601
603 The following examples assume a properly configured security policy.
604 To get a file listing of an unreadable directory:
606 $ sudo ls /usr/local/protected
608 To list the home directory of user yaz on a machine where the file system
610 holding ~yaz is not exported as root:
611 $ sudo -u yaz ls ~yaz
613 To edit the index.html file as user www:
615 $ sudoedit -u www ~www/htdocs/index.html
617 To view system logs only accessible to root and users in the adm group:
619 $ sudo -g adm more /var/log/syslog
621 To run an editor as jim with a different primary group:
623 $ sudoedit -u jim -g audio ~jim/sound.txt
625 To shut down a machine:
627 $ sudo shutdown -r +15 "quick reboot"
629 To make a usage listing of the directories in the /home partition. The
631 commands are run in a sub-shell to allow the ‘cd’ command and file redi‐
632 rection to work.
633 $ sudo sh -c "cd /home ; du -s * | sort -rn > USAGE"
635
637 Error messages produced by sudo include:
638 editing files in a writable directory is not permitted
640 By default, sudoedit does not permit editing a file when any of the
641 parent directories are writable by the invoking user. This avoids
642 a race condition that could allow the user to overwrite an arbi‐
643 trary file. See the sudoedit_checkdir option in sudoers(5) for
644 more information.
645 editing symbolic links is not permitted
647 By default, sudoedit does not follow symbolic links when opening
648 files. See the sudoedit_follow option in sudoers(5) for more in‐
649 formation.
650 effective uid is not 0, is sudo installed setuid root?
652 sudo was not run with root privileges. The sudo binary must be
653 owned by the root user and have the set-user-ID bit set. Also, it
654 must not be located on a file system mounted with the ‘nosuid’ op‐
655 tion or on an NFS file system that maps uid 0 to an unprivileged
656 uid.
657 effective uid is not 0, is sudo on a file system with the 'nosuid' option
659 set or an NFS file system without root privileges?
660 sudo was not run with root privileges. The sudo binary has the
661 proper owner and permissions but it still did not run with root
662 privileges. The most common reason for this is that the file sys‐
663 tem the sudo binary is located on is mounted with the ‘nosuid’ op‐
664 tion or it is an NFS file system that maps uid 0 to an unprivileged
665 uid.
666 fatal error, unable to load plugins
668 An error occurred while loading or initializing the plugins speci‐
669 fied in sudo.conf(5).
670 invalid environment variable name
672 One or more environment variable names specified via the -E option
673 contained an equal sign (‘=’). The arguments to the -E option
674 should be environment variable names without an associated value.
675 no password was provided
677 When sudo tried to read the password, it did not receive any char‐
678 acters. This may happen if no terminal is available (or the -S op‐
679 tion is specified) and the standard input has been redirected from
680 /dev/null.
681 a terminal is required to read the password
683 sudo needs to read the password but there is no mechanism available
684 for it to do so. A terminal is not present to read the password
685 from, sudo has not been configured to read from the standard input,
686 the -S option was not used, and no askpass helper has been speci‐
687 fied either via the sudo.conf(5) file or the SUDO_ASKPASS environ‐
688 ment variable.
689 no writable temporary directory found
691 sudoedit was unable to find a usable temporary directory in which
692 to store its intermediate files.
693 The “no new privileges” flag is set, which prevents sudo from running as
695 root.
696 sudo was run by a process that has the Linux “no new privileges”
697 flag is set. This causes the set-user-ID bit to be ignored when
698 running an executable, which will prevent sudo from functioning.
699 The most likely cause for this is running sudo within a container
700 that sets this flag. Check the documentation to see if it is pos‐
701 sible to configure the container such that the flag is not set.
702 sudo must be owned by uid 0 and have the setuid bit set
704 sudo was not run with root privileges. The sudo binary does not
705 have the correct owner or permissions. It must be owned by the
706 root user and have the set-user-ID bit set.
707 sudoedit is not supported on this platform
709 It is only possible to run sudoedit on systems that support setting
710 the effective user-ID.
711 timed out reading password
713 The user did not enter a password before the password timeout (5
714 minutes by default) expired.
715 you do not exist in the passwd database
717 Your user-ID does not appear in the system passwd database.
718 you may not specify environment variables in edit mode
720 It is only possible to specify environment variables when running a
721 command. When editing a file, the editor is run with the user's
722 environment unmodified.
723
725 su(1), stat(2), login_cap(3), passwd(5), sudo.conf(5), sudo_plugin(5),
726 sudoers(5), sudoers_timestamp(5), sudoreplay(8), visudo(8)
727
729 See the HISTORY.md file in the sudo distribution
730 (https://www.sudo.ws/about/history/) for a brief history of sudo.
731
733 Many people have worked on sudo over the years; this version consists of
734 code written primarily by:
735 Todd C. Miller
737 See the CONTRIBUTORS.md file in the sudo distribution
739 (https://www.sudo.ws/about/contributors/) for an exhaustive list of peo‐
740 ple who have contributed to sudo.
741
743 There is no easy way to prevent a user from gaining a root shell if that
744 user is allowed to run arbitrary commands via sudo. Also, many programs
745 (such as editors) allow the user to run commands via shell escapes, thus
746 avoiding sudo's checks. However, on most systems it is possible to pre‐
747 vent shell escapes with the sudoers(5) plugin's noexec functionality.
748 It is not meaningful to run the ‘cd’ command directly via sudo, e.g.,
750 $ sudo cd /usr/local/protected
752 since when the command exits the parent process (your shell) will still
754 be the same. The -D option can be used to run a command in a specific
755 directory.
756 Running shell scripts via sudo can expose the same kernel bugs that make
758 set-user-ID shell scripts unsafe on some operating systems (if your OS
759 has a /dev/fd/ directory, set-user-ID shell scripts are generally safe).
760
762 If you believe you have found a bug in sudo, you can submit a bug report
763 at https://bugzilla.sudo.ws/
764
766 Limited free support is available via the sudo-users mailing list, see
767 https://www.sudo.ws/mailman/listinfo/sudo-users to subscribe or search
768 the archives.
769
771 sudo is provided “AS IS” and any express or implied warranties, includ‐
772 ing, but not limited to, the implied warranties of merchantability and
773 fitness for a particular purpose are disclaimed. See the LICENSE.md file
774 distributed with sudo or https://www.sudo.ws/about/license/ for complete
775 details.
776Sudo 1.9.14p3 June 18, 2023 Sudo 1.9.14p3