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 639C222DAAF; Tue, 12 Nov 2024 10:38:35 +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=1731407915; cv=none; b=SPiwNEV2ortxHE2C0B8bWwghoNpL0a7ij0cF4vVfqOBYofrkFrda82mSZXLd4ooPuT0/wNgmGe+F89sKDVLarL7MZAHYxKGqrDLEsfcsJxWG7ctU+46JGdgr3FeoSrqGg7ksF4vTfex8Ht7HleSlCOyd6UyjF4eIsw9zmsQlXzc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731407915; c=relaxed/simple; bh=PoMSSZQc3HEgCS9mXz2Em0s+H9nNvwW2RP02zOII+Ew=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TsISQlUShjXTODoPCjH14GGe7tGKlq8wBGTRIu8a2Vjia0OpK8KI00E/x+vKuuElzH7pgNMX93T8cquIc5WFH50hR3bOcFN7WZVdFgd/ax7EOA7GaG9yb/vEybPBr58HPZeci3hoHVHFeFYNtmbteBxEJOKYTdQcVWBfKrdaf4w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=TL4prutQ; 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="TL4prutQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C50EEC4CED6; Tue, 12 Nov 2024 10:38:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1731407915; bh=PoMSSZQc3HEgCS9mXz2Em0s+H9nNvwW2RP02zOII+Ew=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TL4prutQjIE3kZZgzFrHEFUCavNxXJD4KZRDwtyqDn3Esb/Zm687hqA0RxmvdpNnw EwnRyJRw79AaWyQMd8ujfsYiwZgO3ziSZkAlsP3TUSqYs6Sk9OiTDc1AldXzc3oMrZ WCr0o/RPWqVmRM/jZ3Lb+Kw8oChDAChx3GU7Wnhk= 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 6.6 097/119] btrfs: reinitialize delayed ref list after deleting it from the list Date: Tue, 12 Nov 2024 11:21:45 +0100 Message-ID: <20241112101852.426717942@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241112101848.708153352@linuxfoundation.org> References: <20241112101848.708153352@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-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 @@ -615,7 +615,7 @@ static bool insert_delayed_ref(struct bt &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); }