From 840aa7a9802beba62660243aa767574479366e0e Mon Sep 17 00:00:00 2001 From: Johannes Schauer Marin Rodrigues Date: Tue, 6 Sep 2022 07:56:54 +0200 Subject: useradd: avoid creating several GB worth of sparse lastlog and faillog files Closes: #1019245 --- debian/changelog | 6 ++++ ..._lastlog_faillog_do_not_reset_non-existent_data | 37 ++++++++++++++++++++++ debian/patches/series | 2 ++ 3 files changed, 45 insertions(+) create mode 100644 debian/patches/301_lastlog_faillog_do_not_reset_non-existent_data diff --git a/debian/changelog b/debian/changelog index 607477b3..d0806cc0 100644 --- a/debian/changelog +++ b/debian/changelog @@ -1,8 +1,14 @@ shadow (1:4.12.3+dfsg1-1) UNRELEASED; urgency=medium + [ Balint Reczey ] * New upstream release * Refresh patches + [ Johannes Schauer Marin Rodrigues ] + * useradd: cherry-pick patch from upstream to avoid creating several GB worth + of sparse lastlog and faillog files for users with high uid values + (Closes: #1019245) + -- Balint Reczey Sat, 20 Aug 2022 18:18:43 +0200 shadow (1:4.11.1+dfsg1-2) unstable; urgency=medium diff --git a/debian/patches/301_lastlog_faillog_do_not_reset_non-existent_data b/debian/patches/301_lastlog_faillog_do_not_reset_non-existent_data new file mode 100644 index 00000000..0e20995b --- /dev/null +++ b/debian/patches/301_lastlog_faillog_do_not_reset_non-existent_data @@ -0,0 +1,37 @@ +From ebf9b232b012725d2be5e750876c7336cf1c37fd Mon Sep 17 00:00:00 2001 +From: David Kalnischkies +Date: Wed, 24 Aug 2022 13:21:01 +0200 +Subject: [PATCH] useradd: Do not reset non-existent data in {last,fail}log + +useradd does not create the files if they don't exist, but if they exist +it will reset user data even if the data did not exist before creating +a hole and an explicitly zero'd data point resulting (especially for +high UIDs) in a lot of zeros ending up in containers and tarballs. +--- + src/useradd.c | 6 ++++-- + 1 file changed, 4 insertions(+), 2 deletions(-) + +--- a/src/useradd.c ++++ b/src/useradd.c +@@ -1997,8 +1997,9 @@ static void faillog_reset (uid_t uid) + struct faillog fl; + int fd; + off_t offset_uid = (off_t) (sizeof fl) * uid; ++ struct stat st; + +- if (access (FAILLOG_FILE, F_OK) != 0) { ++ if (stat (FAILLOG_FILE, &st) != 0 || st.st_size <= offset_uid) { + return; + } + +@@ -2034,8 +2035,9 @@ static void lastlog_reset (uid_t uid) + int fd; + off_t offset_uid = (off_t) (sizeof ll) * uid; + uid_t max_uid; ++ struct stat st; + +- if (access (LASTLOG_FILE, F_OK) != 0) { ++ if (stat (LASTLOG_FILE, &st) != 0 || st.st_size <= offset_uid) { + return; + } + diff --git a/debian/patches/series b/debian/patches/series index b25583aa..6ecd3726 100644 --- a/debian/patches/series +++ b/debian/patches/series @@ -14,3 +14,5 @@ 463_login_delay_obeys_to_PAM 505_useradd_recommend_adduser 501_commonio_group_shadow + +301_lastlog_faillog_do_not_reset_non-existent_data -- cgit v1.2.1