From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5FABC3FBB77 for ; Tue, 21 Jul 2026 14:41:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784644898; cv=none; b=gH01kHSCxstqJEb5OPWZfmxZ5vqIyAlOWLPibeEvQaXnc9XjflGQvNuqynOtwjBbjilMhywdKehTudjhvOK/uslIL+zC2fOhuZvSnI/abvdFfeJEyWfAlqApUX/q+4VpMJwPcuHz0BKg9TFmBKYk6zcrWKssRYGU9orTDK5pvpI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784644898; c=relaxed/simple; bh=Z2m80WvfGKsxAwDlp1phdArJ7xiisAJkuiPYA7mAvng=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=E22fnZlqcYAO6bmnXPlG0nGHN6KM5nPKgWtiqm3cYYhFI0RQ8dK+IqkeMNuvyn3aX46q0hS728pVVtPhqq5l2utxjlBuJ9iKpmbLESEC9ig0/+nA5r+d5YRGI2OmC/9j3GOT7rF9EeYwtrrNUMQDbfVIYIFWfiwybUR9fwTESJA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=bZ6Z7ROn; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="bZ6Z7ROn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 79C851F00A3A; Tue, 21 Jul 2026 14:41:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784644897; bh=5FA8V0z5hCLctj9+fWDMgI9H8Ev5783eZ3ScJl6TQaA=; h=Subject:To:Cc:From:Date; b=bZ6Z7ROnRvGKbFyPRVlAZPDOopBoV2cHSU4GiVVUzKhtzq6lqzfKcrAMobiDTJAsf yeRTijkGt5XxKAyqaZLIB+Nw6RfdtVJNwdVA66724tuqq0uLns2zRoa+6R8Nuuv3XZ 9d2vBHLo672Spwes6Bbj2axDPbo/s7UHvAg24u94= Subject: FAILED: patch "[PATCH] afs: Fix premature cell exposure through /afs" failed to apply to 6.12-stable tree To: dhowells@redhat.com,brauner@kernel.org,marc.dionne@auristor.com Cc: From: Date: Tue, 21 Jul 2026 16:41:27 +0200 Message-ID: <2026072127-dress-overplay-421f@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.12-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.12.y git checkout FETCH_HEAD git cherry-pick -x 26f17ce6fa3f05cb5965790499c1839094260de4 # git commit -s git send-email --to '' --in-reply-to '2026072127-dress-overplay-421f@gregkh' --subject-prefix 'PATCH 6.12.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 26f17ce6fa3f05cb5965790499c1839094260de4 Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 22 Jun 2026 10:08:53 +0100 Subject: [PATCH] afs: Fix premature cell exposure through /afs AFS cell records are prematurely exposured through the /afs dynamic root by virtue of adding them immediately to the net->cells_dyn_ino IDR when the cell is allocated rather than when it is added to the lookup tree. This allows a candidate record to be accessed, even if it's actually a duplicate or not published yet. Fix this by not adding the cell to cells_dyn_ino until it's confirmed non-duplicate and is being published. A flag is then used to record whether it is added to the IDR to make removal from the IDR conditional. Closes: https://sashiko.dev/#/patchset/20260618155141.2513212-1-dhowells%40redhat.com Signed-off-by: David Howells Link: https://patch.msgid.link/20260622090856.2746629-20-dhowells@redhat.com Fixes: 1d0b929fc070 ("afs: Change dynroot to create contents on demand") cc: Marc Dionne cc: linux-afs@lists.infradead.org Signed-off-by: Christian Brauner (Amutable) diff --git a/fs/afs/cell.c b/fs/afs/cell.c index 9d8937ae24e2..47a2645768d7 100644 --- a/fs/afs/cell.c +++ b/fs/afs/cell.c @@ -205,14 +205,7 @@ static struct afs_cell *afs_alloc_cell(struct afs_net *net, cell->dns_source = vllist->source; cell->dns_status = vllist->status; smp_store_release(&cell->dns_lookup_count, 1); /* vs source/status */ - down_write(&net->cells_lock); - ret = idr_alloc_cyclic(&net->cells_dyn_ino, cell, - 2, INT_MAX / 2, GFP_KERNEL); - up_write(&net->cells_lock); - if (ret < 0) - goto error; atomic_inc(&net->cells_outstanding); - cell->dynroot_ino = ret; cell->debug_id = atomic_inc_return(&cell_debug_id); trace_afs_cell(cell->debug_id, 1, 0, afs_cell_trace_alloc); @@ -306,6 +299,13 @@ struct afs_cell *afs_lookup_cell(struct afs_net *net, goto cell_already_exists; } + ret = idr_alloc_cyclic(&net->cells_dyn_ino, candidate, + 2, INT_MAX / 2, GFP_KERNEL); + if (ret < 0) + goto cant_alloc_ino; + candidate->dynroot_ino = ret; + set_bit(AFS_CELL_FL_HAVE_INO, &candidate->flags); + cell = candidate; candidate = NULL; afs_use_cell(cell, trace); @@ -380,6 +380,11 @@ struct afs_cell *afs_lookup_cell(struct afs_net *net, _leave(" = %p [cell]", cell); return cell; +cant_alloc_ino: + up_write(&net->cells_lock); + afs_put_cell(candidate, afs_cell_trace_put_candidate); + goto error_noput; + cell_already_exists: _debug("cell exists"); cell = cursor; @@ -596,9 +601,11 @@ static void afs_destroy_cell_work(struct work_struct *work) timer_delete_sync(&cell->management_timer); cancel_work_sync(&cell->manager); - down_write(&cell->net->cells_lock); - idr_remove(&cell->net->cells_dyn_ino, cell->dynroot_ino); - up_write(&cell->net->cells_lock); + if (test_bit(AFS_CELL_FL_HAVE_INO, &cell->flags)) { + down_write(&cell->net->cells_lock); + idr_remove(&cell->net->cells_dyn_ino, cell->dynroot_ino); + up_write(&cell->net->cells_lock); + } call_rcu(&cell->rcu, afs_cell_destroy); } diff --git a/fs/afs/internal.h b/fs/afs/internal.h index 785c646856d7..601f01e5c15f 100644 --- a/fs/afs/internal.h +++ b/fs/afs/internal.h @@ -388,6 +388,7 @@ struct afs_cell { #define AFS_CELL_FL_NO_GC 0 /* The cell was added manually, don't auto-gc */ #define AFS_CELL_FL_DO_LOOKUP 1 /* DNS lookup requested */ #define AFS_CELL_FL_CHECK_ALIAS 2 /* Need to check for aliases */ +#define AFS_CELL_FL_HAVE_INO 3 /* Have dynroot_ino */ enum afs_cell_state state; short error; enum dns_record_source dns_source:8; /* Latest source of data from lookup */