* lib/fchownat.c (rpl_fchownat) [CHOWN_TRAILING_SLASH_BUG]:
Do the right thing if fstatat fails with EOVERFLOW.
This matters only on obsolete platforms like Solaris 9,
but it’s easy to do it right. Simplify neighboring code.
---
ChangeLog | 6 ++++++
lib/fchownat.c | 23 +++++++++++------------
2 files changed, 17 insertions(+), 12 deletions(-)
diff --git a/ChangeLog b/ChangeLog
index d76f5f9038..08dd88a67a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,11 @@
2025-09-20 Paul Eggert <egg...@cs.ucla.edu>
+ fchownat: fix unlikely EOVERFLOW bug
+ * lib/fchownat.c (rpl_fchownat) [CHOWN_TRAILING_SLASH_BUG]:
+ Do the right thing if fstatat fails with EOVERFLOW.
+ This matters only on obsolete platforms like Solaris 9,
+ but it’s easy to do it right. Simplify neighboring code.
+
fchownat: fix missing HAVE_FCHOWNAT
* m4/fchownat.m4 (gl_FUNC_FCHOWNAT): Use AC_CHECK_FUNCS instead of
AC_CHECK_FUNC, so that we define HAVE_FCHOWNAT if fchownat
diff --git a/lib/fchownat.c b/lib/fchownat.c
index 453810d653..3e15fde1da 100644
--- a/lib/fchownat.c
+++ b/lib/fchownat.c
@@ -1,4 +1,6 @@
-/* This function serves as replacement for a missing fchownat function,
+/* A more POSIX-compliant fchownat
+
+ This serves as replacement for a missing fchownat function,
as well as a workaround for the fchownat bug in glibc-2.4:
<https://lists.ubuntu.com/archives/ubuntu-users/2006-September/093218.html>
when the buggy fchownat-with-AT_SYMLINK_NOFOLLOW operates on a symlink, it
@@ -98,17 +100,14 @@ rpl_fchownat (int fd, char const *file, uid_t owner, gid_t
group, int flag)
}
# endif
# if CHOWN_TRAILING_SLASH_BUG
- {
- size_t len = strlen (file);
- struct stat st;
- if (len && file[len - 1] == '/')
- {
- if (fstatat (fd, file, &st, 0))
- return -1;
- if (flag == AT_SYMLINK_NOFOLLOW)
- return fchownat (fd, file, owner, group, 0);
- }
- }
+ if (file[0] && file[strlen (file) - 1] == '/')
+ {
+ struct stat st;
+ int r = fstatat (fd, file, &st, 0);
+ if (r < 0 && errno != EOVERFLOW)
+ return r;
+ flag &= ~AT_SYMLINK_NOFOLLOW;
+ }
# endif
return fchownat (fd, file, owner, group, flag);
}
--
2.51.0
