Your message dated Tue, 26 Jul 2022 10:34:07 +0000 with message-id <[email protected]> and subject line Bug#682156: fixed in adduser 3.125 has caused the Debian Bug report #682156, regarding delgroup I/O requirements are O(n^2) with regards to number of configured users to be marked as done.
This means that you claim that the problem has been dealt with. If this is not the case it is now your responsibility to reopen the Bug report if necessary, and/or fix the problem forthwith. (NB: If you are a system administrator and have no idea what this message is talking about, this may indicate a serious mail system misconfiguration somewhere. Please contact [email protected] immediately.) -- 682156: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=682156 Debian Bug Tracking System Contact [email protected] with problems
--- Begin Message ---Package: adduser Version: 3.112+nmu2 delgroup is a wrapper to groupdel which performs additional validations. It checks to see whether any other user on the system has, as its primary group, the group that it is potentially deleting. It does so with the following code: setpwent; while ((my $acctname,my $primgrp) = (getpwent)[0,3]) { if( $primgrp eq $gr_gid ) { fail (7, gtx("`%s' still has `%s' as their primary group!\n"),$acctname,$group); } } endpwent; Perl's implementation of getpwent will call getspnam() for each user to get the shadow password. On a default system (using /etc/passwd and /etc/shadow) this means, for each line of /etc/passwd, perl will open /etc/shadow, scan it until it finds the matching user, and close the file. Given adding users adds lines to /etc/passwd and /etc/shadow, this means the overall I/O complexity for deleting a group is O(n^2). On systems with ~100k users this quickly ends up being hundreds of gigabytes that needs to be read and processed in order to remove a group; given how often delgroup gets called from postrm scripts this can make a lot of operations rather expensive. groupdel performs the same check from C, using getpwent() without calling the getspnam(), so safety-wise this check is not needed. The only thing we gain from it is the opportunity to detect the error before printing "Removing group ..." and calling groupdel. groupdel has a return value specifically for this case (it will return 8) in the event we wanted to make any behavior conditional on this case. The simplest fix is to simply remove the offending lines of perl entirely. This will result in a slightly different output being printed when attempting to remove a group in use, but will otherwise behave the same, as so: With current delgroup: # delgroup root /usr/sbin/delgroup: `root' still has `root' as their primary group! If offending code were simply removed: # delgroup root Removing group `root' ... groupdel: cannot remove the primary group of user 'root' /usr/sbin/delgroup: `/usr/sbin/groupdel root' returned error code 8. Exiting. The bug was introduced in this commit: http://anonscm.debian.org/viewvc/adduser/trunk/deluser?r1=233&r2=234&; and it's entirely plausible (I haven't checked) that groupdel didn't have any check at all at this point in time. If people believe it's unacceptable to simply remove the check and rely on groupdel to fail, this also suggests an alternate approach to fixing this bug -- calling out to grep via a subshell will be O(n) instead of O(n^2) and should work fine on systems with much larger numbers of users. Daniel
--- End Message ---
--- Begin Message ---Source: adduser Source-Version: 3.125 Done: Marc Haber <[email protected]> We believe that the bug you reported is fixed in the latest version of adduser, which is due to be installed in the Debian FTP archive. A summary of the changes between this version and the previous one is attached. Thank you for reporting the bug, which will now be closed. If you have further comments please address them to [email protected], and the maintainer will reopen the bug report if appropriate. Debian distribution maintenance software pp. Marc Haber <[email protected]> (supplier of updated adduser package) (This message was generated automatically at their request; if you believe that there is a problem with it please contact the archive administrators by mailing [email protected]) -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 Format: 1.8 Date: Tue, 26 Jul 2022 09:57:52 +0200 Source: adduser Architecture: source Version: 3.125 Distribution: experimental Urgency: medium Maintainer: Debian Adduser Developers <[email protected]> Changed-By: Marc Haber <[email protected]> Closes: 57280 398802 541620 682156 1012492 1015907 Changes: adduser (3.125) experimental; urgency=medium . [ Marc Haber ] * remove debconf. (Closes: #57280, #398802) * install (add|del)user.conf as examples. * install adduser.conf as dpkg-conffile directly to /etc. (Closes: #541620) * remove postinst/postrm. (Closes: #1012492) . [ Jason Franklin ] * Remove the unused "get_users_groups" subroutine. (Closes: #1015907) . [ Matt Barry ] * Do not check for group being empty on 'delgroup'. (Closes: #682156) Checksums-Sha1: d10b88eaafedf88528ce1d067b2eec32614721a6 1671 adduser_3.125.dsc df800d2b0680c00fb2f62d1d1db5f4241c4de279 224132 adduser_3.125.tar.xz ed3caca334b35f7f6623348fb64b2efb6e47f3e5 5651 adduser_3.125_source.buildinfo Checksums-Sha256: 277bde3cb4c6e3e0de5a18bc131a2e72be0708b5aa6cb04f8660e3ac300177ea 1671 adduser_3.125.dsc 962be3f7cbc907a06044dbd4ba3974d51069bb01884718cf7671d592549b4a58 224132 adduser_3.125.tar.xz b900414d720f71c43ff514cead02e59e257873ae40ebfb5c21db11196ce0200a 5651 adduser_3.125_source.buildinfo Files: 8c99a88f29c93a8338d514e63151088c 1671 admin important adduser_3.125.dsc f26b8bd8ae1f8c1de06e85a74ab7b0cd 224132 admin important adduser_3.125.tar.xz 5cf1c2d28bc98a17d13788c0ce442a91 5651 admin important adduser_3.125_source.buildinfo -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEE6QL5UJ/L0pcuNEbjj3cgEwEyBEIFAmLfQdwACgkQj3cgEwEy BEIEQhAAkz64JtkXcdEMI4RsijAUAHZjSLPOLK+Ku+kpsduPwFwE2B0DSYOHTYVA SZZTgk0izzX5ORpt7Sx3DiAYZlfaWGoc+R9CCCdfBewdV5nhpUip7npEFJzbXzur 70K6S8CkPDQ9XAXgsW57IgLmq8O9lrm+JSpUQGki7aeJnK3Oj8QheUbe5Mncb9TL uUZ0UOtIsdg1kYGdy+rPkPQ55rb2lia8+/ITPYSP1MLq3I10CrxzVKi9IXq8FrHl v/H5n4AKzWpzN45ROIRECYh2lagzutnxRIedIQEZyVFgZ37vUuEXD3yR/AK2Uec1 jTYimsMJCXYs1yBDF+lfbs+EF3Z+LynSWrFzngFP0JE3rhJ9Y9KCj3xkjdDeO/F2 FAYYBLllcqU1i0FR27KXIC5zNldZS+TNv0k7FZePj/q93aVC74s6bwr+HV6JF24S m4JyYXq76kN4W5nlJtlkzq52qoqBdPQh+jFlcVdMn/WZc/jQVLHkxnGgmGSowSmn cYoHjRNNZcmmeXZ6pxK5eK72pTycXPRBuZIqllInCs4v0uiZ+JNmJuIf4pclP0Wt pVTWEepRMbfZtDt8Xs2u8TIGIvmzSIcPjj05UrqWq1xHaW24fb1Xbttwnv1pZRkL KxPE9zrNTXq2nX+Z80kvCPRR6rPWKT+aKVuIh56K79RA+x2rQR8= =qYpl -----END PGP SIGNATURE-----
--- End Message ---
