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 4342538C41B for ; Tue, 21 Jul 2026 14:41:25 +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=1784644887; cv=none; b=FTlPxfhKnscpInto1D3oqfiNrQXJZHnrw0dxw9hGjfvY/b6gm20VncipzM3Pnjh8T1iqhV6+tZA/zAigqTEjUgKhl3y+4fkewtdH50KcvRfWyNCPkcFJeI46ogV2lPUxcQ2293GNlgicPRR3rbpDTcq8yK0itzOgbgW+Br0ARTE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784644887; c=relaxed/simple; bh=tXeV/i+rA2KEsUu02/SnfAKYgDFRB7WUwqBxXRRRb1E=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=blYsAS3HVS+OJQZw+zWFZZz3LiD2l07dCCjg5bg3ID5HzNqG+/r1Nm79CzR/9el+kOJ9/fRZe/qG69nyXpxKo7qZyT0EGs0eHUqEy3nWILPVAzncIPCZt1xYhckNnZ41EhdIsHxsnOIcwjtx6hN8I8fsQmHFvMgGXGukhyD6oUg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=kR7ryDg9; 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="kR7ryDg9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 611EE1F000E9; Tue, 21 Jul 2026 14:41:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784644885; bh=tSH1ntLrGzWE4qrjZv7nE/CQJt6XU3T++AxWL4DVt8M=; h=Subject:To:Cc:From:Date; b=kR7ryDg9AFZliH/ySm0rhx/07MhplPEbf3g+pigSNzhHC4ak+mhSHTFmPNcYzEAkf aLmFKon2563h6ZuS+yJiaJVht0V63kMhTIHqjSgpd+KpCJRZSkjdRytgFQMqZvd3Y7 DVsFDqhryZM1/fbGQqDYaapXoSy8GLEHxrVJVeAQ= Subject: FAILED: patch "[PATCH] afs: Fix lack of locking around modifications of" 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 16:41:16 +0200 Message-ID: <2026072116-feeble-cusp-7fff@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 55e841836c6f4646490f7b0347192b7a92d431ba # git commit -s git send-email --to '' --in-reply-to '2026072116-feeble-cusp-7fff@gregkh' --subject-prefix 'PATCH 6.12.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 55e841836c6f4646490f7b0347192b7a92d431ba Mon Sep 17 00:00:00 2001 From: David Howells Date: Mon, 22 Jun 2026 10:08:52 +0100 Subject: [PATCH] afs: Fix lack of locking around modifications of net->cells_dyn_ino Fix the lack of locking around modifications of net->cells_dyn_ino by taking net->cells_lock exclusively. This also requires to cell to be removed from net->cells_dyn_ino in afs_destroy_cell_work() rather than in afs_cell_destroy() as the latter runs in RCU cleanup context and sleeping locks cannot be taken there. Fixes: 1d0b929fc070 ("afs: Change dynroot to create contents on demand") Closes: https://sashiko.dev/#/patchset/20260618074903.2374756-1-dhowells%40redhat.com Signed-off-by: David Howells Link: https://patch.msgid.link/20260622090856.2746629-19-dhowells@redhat.com 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 fbb8a43aa7cd..9d8937ae24e2 100644 --- a/fs/afs/cell.c +++ b/fs/afs/cell.c @@ -205,8 +205,10 @@ 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); @@ -579,7 +581,6 @@ static void afs_cell_destroy(struct rcu_head *rcu) afs_put_vlserverlist(net, rcu_access_pointer(cell->vl_servers)); afs_unuse_cell(cell->alias_of, afs_cell_trace_unuse_alias); key_put(cell->anonymous_key); - idr_remove(&net->cells_dyn_ino, cell->dynroot_ino); kfree(cell->name - 1); kfree(cell); @@ -594,6 +595,11 @@ static void afs_destroy_cell_work(struct work_struct *work) afs_see_cell(cell, afs_cell_trace_destroy); 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); + call_rcu(&cell->rcu, afs_cell_destroy); } diff --git a/fs/afs/dynroot.c b/fs/afs/dynroot.c index 1d5e33bc7502..6e3c8c691ba9 100644 --- a/fs/afs/dynroot.c +++ b/fs/afs/dynroot.c @@ -278,7 +278,7 @@ static struct dentry *afs_lookup_atcell(struct inode *dir, struct dentry *dentry } /* - * Transcribe the cell database into readdir content under the RCU read lock. + * Transcribe the cell database into readdir content under net->cells_lock. * Each cell produces two entries, one prefixed with a dot and one not. */ static int afs_dynroot_readdir_cells(struct afs_net *net, struct dir_context *ctx)