Re: Putting a file in a shared namespace causes Panic in quota.c

6 Jan 2026

      Hi,

Dovecot 1.4.1; quota_ignore = yes (as described by Aki);
dovecot_config_version = 2.4.0 (Debian default)
--> No crash

Dovecot 1.4.2 - WITHOUT quota_ignore=yes
--> Crash

Dovecot 1.4.2; quota_ignore = yes
--> No crash

For 2. and 3. I tested dovecot_config_version = 2.4.0 and 2.4.2
--> No difference.
Thanks for looking into it + Best regards,
Christopher
Am 05.01.26 um 07:30 schrieb Aki Tuomi:
...
...
On 04/01/2026 20:13 EET Christopher V. via dovecot
<dovecot@dovecot.org> wrote:
Dear all,
I guess I found a bug.
I'm currently testing a migration of my Debian based dovecot bare metal
installation from 2.3.19 --> 2.4.1
I'm using shared mailboxes.
My understanding from the documentation is: "Quota plugin considers
shared namespaces against owner's quota" and "The quota limits are also
taken from the userdb."
The following setup leads to a "Panic: file quota.c":

Quota is defined per-user and defined in a MySQL Database (and looked
up as part of userdb)
User A shares directory "Inbox/teilemich" with user B.
User B has full access rights (details see below)
User A has a quota of 100MB - currently using 60%
User B has a quota of 4GB - currently using 550MB
User A puts mail xyz in the shared directory --> works
User B puts mail abc in the shared directory --> error message (see
below) and mail is not stored.
Defining the following not-overwritable global quota > 550 MB eliminates
the error message. Defining a global quota < 550 MB still leads to the
error message.
quota "User quota" {
storage_size = 560M
storage_grace = 10M
}
Defining an overwritable global quota that is > 550 MB still leads to
the error message.
quota_storage_size = 560M
quota "User quota" {
storage_grace = 10M
}
Can you please check, if this is a bug?
If you need some details I'm happy to provide it.
Also - I would be very grateful for a workaround / fix.
Thanks for all the effort & Best regards,
Christopher

Hi,
does it help if you add
namespace shared {
quota_ignore = yes
}
Should not crash in any case... any chance you could test with 2.4.2,
packages from https://repo.dovecot.org/
Aki
Hi,

Dovecot 1.4.1; quota_ignore = yes (as described by Aki);
dovecot_config_version = 2.4.0 (Debian default)
--> No crash

Dovecot 1.4.2 - WITHOUT quota_ignore=yes
--> Crash

Dovecot 1.4.2; quota_ignore = yes
--> No crash

For 2. and 3. I tested dovecot_config_version = 2.4.0 and 2.4.2
--> No difference.
Thanks for looking into it + Best regards,
Christopher
Am 05.01.26 um 07:30 schrieb Aki Tuomi:
   On 04/01/2026 20:13 EET Christopher V. via dovecot
   &lt;[1]dovecot@dovecot.org> wrote:

   Dear all,

   I guess I found a bug.

   I'm currently testing a migration of my Debian based dovecot bare
   metal
   installation from 2.3.19 --> 2.4.1
   I'm using shared mailboxes.
   My understanding from the documentation is: "Quota plugin considers
   shared namespaces against owner's quota" and "The quota limits are
   also
   taken from the userdb."

   The following setup leads to a "Panic: file quota.c":
   * Quota is defined per-user and defined in a MySQL Database (and
   looked
   up as part of userdb)
   * User A shares directory "Inbox/teilemich" with user B.
   * User B has full access rights (details see below)
   * User A has a quota of 100MB - currently using 60%
   * User B has a quota of 4GB - currently using 550MB
   * User A puts mail xyz in the shared directory --> works
   * User B puts mail abc in the shared directory --> error message (see
   below) and mail is not stored.

   Defining the following not-overwritable global quota > 550 MB
   eliminates
   the error message. Defining a global quota &lt; 550 MB still leads to the
   error message.
   quota "User quota" {
          storage_size = 560M
          storage_grace = 10M
   }

   Defining an overwritable global quota that is > 550 MB still leads to
   the error message.
   quota_storage_size = 560M
   quota "User quota" {
           storage_grace = 10M
   }

   Can you please check, if this is a bug?
   If you need some details I'm happy to provide it.

   Also - I would be very grateful for a workaround / fix.

   Thanks for all the effort & Best regards,

   Christopher

   -----------------------------------------------------

 Hi,

 does it help if you add

 namespace shared {
     quota_ignore = yes
 }

 Should not crash in any case... any chance you could test with 2.4.2,
 packages from [2]https://repo.dovecot.org/

 Aki
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