From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793831525; b=IDS6JqZ7mQV0GMLjBL1hJqvE4XCmcmOrcekXPsKCtRV/6na7NEMRUCojGpGXCUWEXshz QVHU0mVDaGB983V+UctFeyG/dOF1j2N7X69PlLgrk9ecp91mp+8SEKgfgE6Ut1fVom6l3 JzZ3w/KmAj+L04aL1szEmPWBUzvk5hYCyaNC15rTtyTNG1Z0u4cagYbDCsvLTQbSu67E3 Uwjk4QN/uBQ8iEZfn+BycavCLmL/lSH4deWaZhnKF1drqeefpNDnwsL4W/XJh9PdJolDl lewJFdLlf8UUlzFL939HWhsyVpebsq9TrQVtueBa3xey8dbkRvzFCgiR8D5hK64c85A== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793831525; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=GJA6m1Nalr7jf5uJRsYcf1fwQLy/WeqaMCQlYo5RzFI=; b=jvs66VJ6ix9MPtLKKMSCP2CVphiuBi057aIaCaUu0dx1RPjX7z0N45bA+Cwlm+ie29+w meHa+WzNIJKYlhF45hqcTO534TBm0LfxtCZbjhLaHv+n1fB4Iuj8Cxr/EMOb1CeTq9226 GR9BbdQ/Ud0hIBJ8JLoHtDQxZq3JPIdW9Ou8Wnw8LzLQkZfUWcxIYgaHnVMA57WBUBXUi BxgYkW8woSyrKiDkW8aFXKirqMZLTjzKtemWjvNYFdscPF/nH8noLv8VEV/WKFhdezneM c825bEW+zGq20u/o1qKYbXwst9UHYYwrPPWgR1cNl8ePitIv6+ELxinvYUxq/Mzd0Sg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=PposN4aG; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 699B6606A33D; Wed, 4 Nov 2026 22:32:05 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=PposN4aG Received: by smtp.kernel.org (Postfix) with ESMTPSA id 054811F0093A; Wed, 4 Nov 2026 22:32:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793831525; bh=GJA6m1Nalr7jf5uJRsYcf1fwQLy/WeqaMCQlYo5RzFI=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=PposN4aGRZnc9SdplgQ/nn00jxrHDXW/FMyQgRBd7KJtsEiPUJwiD9JiumY6+zgK7 LbI0Q7kQYbB4hxDUXaVHJ2B6VC/NJKUtahrDCK8ciEVdEAiSQr/eempVCQoD9s2xwH k1ivfK3f4aOeleknGamh64HIyzWdcBy+MEx00mcM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Brian Foster , Christoph Hellwig , Andrea Parri , "Christian Brauner (Amutable)" Subject: [PATCH 6.18 0718/1005] iomap: dont resubmit an ioend after ->writeback_submit() failed Date: Wed, 4 Nov 2026 16:07:31 -0500 Message-ID: <20261104211103.644309592@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261104211043.516122098@linuxfoundation.org> References: <20261104211043.516122098@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Andrea Parri commit 3f517370076f1fedaa38cd8c78ceb73616b79336 upstream. iomap_add_to_ioend() submits the pending ioend through ->writeback_submit() before allocating a new one for the current range. When the submission fails the helper completes the ioend with an error, but iomap_add_to_ioend() returns the error without clearing wpc->wb_ctx. iomap_writepages() then submits whatever wpc->wb_ctx points to, so the already completed ioend is submitted a second time. For XFS the second bio_endio() lands in xfs_end_bio(), which list_add_tail()s the already linked ioend into ip->i_ioend_list. This corrupts the list and leaves a use-after-free/double-free window against the ioend completion worker. Reproduced with a fault-injected ->writeback_submit() failure on a reflinked XFS file with several CoW writeback ranges in flight: the unfixed kernel hits repeated "list_add double add" warnings from __list_add_valid_or_report(), the fixed kernel fails writeback cleanly. Clear wpc->wb_ctx when ->writeback_submit() fails. The old iomap_submit_ioend() cleared the context unconditionally; that clear was lost when submission moved to iomap_ioend_writeback_submit(). The final ->writeback_submit() call in iomap_writepages() needs no equivalent fix: it is the last thing the function does before returning, and every caller allocates its iomap_writepage_ctx on the stack for a single call, so wpc->wb_ctx is never read again afterwards. Fixes: f4fa7981fa26 ("iomap: hide ioends from the generic writeback code") Cc: stable@vger.kernel.org # v6.17 Reviewed-by: Brian Foster Reviewed-by: Christoph Hellwig Signed-off-by: Andrea Parri Link: https://patch.msgid.link/90fbd42df4f51306e57a95830d2d53873f630eb9.1790342457.git.parri.andrea@gmail.com Signed-off-by: Christian Brauner (Amutable) Signed-off-by: Greg Kroah-Hartman --- fs/iomap/ioend.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) --- a/fs/iomap/ioend.c +++ b/fs/iomap/ioend.c @@ -187,8 +187,16 @@ ssize_t iomap_add_to_ioend(struct iomap_ new_ioend: if (ioend) { error = wpc->ops->writeback_submit(wpc, 0); - if (error) + if (error) { + /* + * ->writeback_submit() completed the ioend + * with an error, so drop the stale context; + * iomap_writepages() would otherwise submit + * it a second time. + */ + wpc->wb_ctx = NULL; return error; + } } wpc->wb_ctx = ioend = iomap_alloc_ioend(wpc, pos, ioend_flags); }