From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 045C818873F; Fri, 15 Nov 2024 06:40:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731652828; cv=none; b=WNk/LrJzltv0iqTyFFOJ8yTXJlb9tviHwe/6vcQNsjDRU7HQwSOmk46US5M6lo4ftFu+mrGKbG/e6cRTgtTzeezpHGAAnQlKMg+SmBbcCRASBiHh5PihzuplDIT9hpFwjOrGQ65nxHm3VZwSYAViJvUrZoUeaiOYl2GQK7Zknhs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731652828; c=relaxed/simple; bh=wjLw7lHdUhDujAycCyKq/pXl9QrC0ez9gjpyQLkos2M=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jPaNz6aebfnlzGgLEF+NfUpODzFpbMWDyZE2Zp+vDaOkeKnwaaH8RWQtkIS8lYmH3Y9dNACmEXJ3PTrhnwaW2ivYwagEw8g7TPs3LcutEp6S3Mmawn50Dvhu3NU0d6EZAOUzQ83GeydMiCeKB5kbI9DT93PnVTYGdCFMafSyioM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=bvwFZKqN; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="bvwFZKqN" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6ACDDC4CECF; Fri, 15 Nov 2024 06:40:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1731652827; bh=wjLw7lHdUhDujAycCyKq/pXl9QrC0ez9gjpyQLkos2M=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bvwFZKqNflNq0z7AAD9jmP7O6wiU+kF7LQIRUTFBY0RU3LaEnoo17Xxca/ilsBvSg emUJZgmVChroxFYz+Xlybj1aCqxaeWdTAcNC6Y4REF3rhYVS2PRKxkNCizZLvu49xb /LyUOuESKk5pa2eKWhBCfYfKfztQav08JFxsTcOw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Johannes Thumshirn , Filipe Manana , David Sterba Subject: [PATCH 4.19 26/52] btrfs: reinitialize delayed ref list after deleting it from the list Date: Fri, 15 Nov 2024 07:37:39 +0100 Message-ID: <20241115063723.802210236@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241115063722.845867306@linuxfoundation.org> References: <20241115063722.845867306@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Filipe Manana commit c9a75ec45f1111ef530ab186c2a7684d0a0c9245 upstream. At insert_delayed_ref() if we need to update the action of an existing ref to BTRFS_DROP_DELAYED_REF, we delete the ref from its ref head's ref_add_list using list_del(), which leaves the ref's add_list member not reinitialized, as list_del() sets the next and prev members of the list to LIST_POISON1 and LIST_POISON2, respectively. If later we end up calling drop_delayed_ref() against the ref, which can happen during merging or when destroying delayed refs due to a transaction abort, we can trigger a crash since at drop_delayed_ref() we call list_empty() against the ref's add_list, which returns false since the list was not reinitialized after the list_del() and as a consequence we call list_del() again at drop_delayed_ref(). This results in an invalid list access since the next and prev members are set to poison pointers, resulting in a splat if CONFIG_LIST_HARDENED and CONFIG_DEBUG_LIST are set or invalid poison pointer dereferences otherwise. So fix this by deleting from the list with list_del_init() instead. Fixes: 1d57ee941692 ("btrfs: improve delayed refs iterations") CC: stable@vger.kernel.org # 4.19+ Reviewed-by: Johannes Thumshirn Signed-off-by: Filipe Manana Reviewed-by: David Sterba Signed-off-by: David Sterba Signed-off-by: Greg Kroah-Hartman --- fs/btrfs/delayed-ref.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/btrfs/delayed-ref.c +++ b/fs/btrfs/delayed-ref.c @@ -426,7 +426,7 @@ static int insert_delayed_ref(struct btr &href->ref_add_list); else if (ref->action == BTRFS_DROP_DELAYED_REF) { ASSERT(!list_empty(&exist->add_list)); - list_del(&exist->add_list); + list_del_init(&exist->add_list); } else { ASSERT(0); }