chown --from option can be used to restrict the list of files
concerned by the chown.
However this is true only for the latest --from option provided on the
command line. One can run chown --from=1000:1000 --from=0:0, in that
case the first --from will be silently discarded.
It is an issue on systems where sysadmins naively provide a sudo rule
for their users expecting to restrict its usage for a specific owner.
We can fix by rejecting the cases where --from option is provided multiple
times and uid or gid are set twice.
* src/chown.c: prevent multiple --from options
* tests/chown/basic.sh: prevent multiple --from options
---
src/chown.c | 14 ++++++++++++--
tests/chown/basic.sh | 9 +++++++++
2 files changed, 21 insertions(+), 2 deletions(-)
diff --git a/src/chown.c b/src/chown.c
index c1db307ab..a06bf6ed4 100644
--- a/src/chown.c
+++ b/src/chown.c
@@ -227,11 +227,21 @@ main (int argc, char **argv)
case FROM_OPTION:
{
- const char *e = parse_user_spec (optarg,
- &required_uid, &required_gid,
+ const char *e;
+ uid_t parsed_required_uid = -1;
+ gid_t parsed_required_gid = -1;
+ e = parse_user_spec (optarg,
+ &parsed_required_uid,
+ &parsed_required_gid,
NULL, NULL);
if (e)
die (EXIT_FAILURE, 0, "%s: %s", e, quote (optarg));
+ if ((parsed_required_uid != -1 && required_uid != -1) ||
+ (parsed_required_gid != -1 && required_gid != -1))
+ die (EXIT_FAILURE, 0, "%s",
+ _("from option provided multiple times"));
+ required_uid = parsed_required_uid;
+ required_gid = parsed_required_gid;
break;
}
diff --git a/tests/chown/basic.sh b/tests/chown/basic.sh
index faeeb82aa..2ccfd959d 100755
--- a/tests/chown/basic.sh
+++ b/tests/chown/basic.sh
@@ -56,4 +56,13 @@ chown --no-dereference --from=0:1 2:010 slink || fail=1
# owner/group on the symlink should be changed
set _ $(ls -n slink); shift; test "$3:$4" = 2:10 || fail=1
+# Ensure two from are reported properly as error
+returns_ 1 chown --from=0:0 --from=1:1 0 f > out 2>&1|| fail=1
+printf "chown: from option provided multiple times\n" > exp
+compare exp out || fail=1
+
+# Unless they set different attributes
+chown --from=0 --from=:0 0 f || fail=1
+
+
Exit $fail
--
2.16.4
