If a root directory is configured by the user, lookup users and groups
in the /etc/passwd and /etc/group of that root directory instead of the
host's /etc/passwd and /etc/group.

This is especially important when building Debian chroots on distros
that are not Debian based and where the host's /etc/passwd and /etc/group
is using passwd and group entries that differ wildly from those shipped
by Debian or its derivatives, causing dpkg stat-overrides to fail because
a group or user cannot be found in the host's passwd or group entries.
---
lib/dpkg/db-fsys-override.c | 64 +++++++++++++++++++++++++++++++------
1 file changed, 54 insertions(+), 10 deletions(-)

diff --git a/lib/dpkg/db-fsys-override.c b/lib/dpkg/db-fsys-override.c
index e079c5ffb..29adaf134 100644
--- a/lib/dpkg/db-fsys-override.c
+++ b/lib/dpkg/db-fsys-override.c
@@ -58,12 +58,34 @@ statdb_parse_uid(const char *str)
ohshit(_("invalid statoverride uid %s"), str);
uid = (uid_t)value;
} else {
- struct passwd *pw = getpwnam(str);
+ char *passwd;
+ FILE *file;
+
+ uid = (uid_t)-1;
+ passwd = dpkg_fsys_get_path("etc/passwd");
+
+ file = fopen(passwd, "r");
+ free(passwd);
+ if (!file) {
+ if (errno != ENOENT)
+ ohshite(_("failed to open etc/passwd file"));
+ } else {
+ struct passwd *pw;
+
+ errno = 0;
+ while ((pw = fgetpwent(file))) {
+ if (strcmp(pw->pw_name, str) == 0)
+ break;
+ }

- if (pw == NULL)
- uid = (uid_t)-1;
- else
- uid = pw->pw_uid;
+ fclose(file);
+
+ if (errno > 0)
+ oh

Hi!

On Tue, 2023-03-07 at 13:05:51 +0100, Daan De Meyer wrote:

If a root directory is configured by the user, lookup users and groups
in the /etc/passwd and /etc/group of that root directory instead of the host's /etc/passwd and /etc/group.

This is especially important when building Debian chroots on distros
that are not Debian based and where the host's /etc/passwd and /etc/group
is using passwd and group entries that differ wildly from those shipped
by Debian or its derivatives, causing dpkg stat-overrides to fail because
a group or user cannot be found in the host's passwd or group entries.

Indeed, nice catch, and thanks for the patch (and for filing the bug
report). While I don't quite like the hardcoding of the filenames, this
is something that was already implicitly done by the system libc
(including chroots and similar).

I'll be queueing this as part of the greater refactoring for the
dpkg sysusers support, and will probably add a way to override those
pathnames externally to mitigate this hardcoding.

Thanks,
Guillem

--- SoupGate-Win32 v1.05
* Origin: fsxNet Usenet Gateway (21:1/5)

From: [email protected]

Hi Guillem,

Did you actually ever apply this patch? I assumed it would appear in a
new dpkg release given your previous email but looking at the dpkg git
branch it seems it was never applied? This is rather unfortunate as I
was hoping to have this issue fixed by now.

Cheers,

Daan

On Sat, 8 Apr 2023 at 12:16, Guillem Jover <[email protected]> wrote:

Hi!

On Tue, 2023-03-07 at 13:05:51 +0100, Daan De Meyer wrote:

If a root directory is configured by the user, lookup users and groups
in the /etc/passwd and /etc/group of that root directory instead of the host's /etc/passwd and /etc/group.

This is especially important when building Debian chroots on distros
that are not Debian based and where the host's /etc/passwd and /etc/group is using passwd and group entries that differ wildly from those shipped
by Debian or its derivatives, causing dpkg stat-overrides to fail because
a group or user cannot be found in the host's passwd or group entries.

Indeed, nice catch, and thanks for the patch (and for filing the bug
report). While I don't quite like the hardcoding of the filenames, this
is something that was already implicitly done by the system libc
(including chroots and similar).

I'll be queueing this as part of the greater refactoring for the
dpkg sysusers support, and will probably add a way to override those pathnames externally to mitigate this hardcoding.

Thanks,
Guillem

--- SoupGate-Win32 v1.05
* Origin: you cannot sedate... all the things you hate (1:229/2)