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 D13AC1E8320; Tue, 16 Jun 2026 15:22:55 +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=1781623376; cv=none; b=spl0UNf6PpIHZ67ZH+oxibFjPEz0XNepFEScexn6e2OcPdsRQI6Wed3yHaA6aFoT7mQhlz9OAffxi4MtA8O2lBJG2EgdFq/HynFJ2ehNEZl7ppz54orYnsDyjrjku3eVRf5nQ91q6ADcdWLizsCbBigU4p+nYoC7yMNndCsxgjI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1781623376; c=relaxed/simple; bh=GZWJwvqWOmtadTZv9Evo72J2oCfE2+kzT4bJIH/Rc+U=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Ty33xuncqqz3R6Ngf4eIWOxwIEg7U4sYCa+NS5i47wO+xvoY8RDJApvy3ROB0gUDbI7uaOYrjfh22RC7LLElF1DdYG6O2mwlfuebrRBJxmtcRihpZNcP5m6r9/nR/MW7NhRuPWBU4OzTZnup78IRK35r74qotpZn1TPuPM23rQU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=FLAZOqqp; 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="FLAZOqqp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id B2A4C1F000E9; Tue, 16 Jun 2026 15:22:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1781623375; bh=1GVhf7ubM3ePhibBrcJ1TbuhxLrLzVbEClpSTp2RLwo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=FLAZOqqpeJvhIlKQgVA+kmRVcUXRCOOf3KoI91gXDIHhqEAw3kQ1jtmlMpvPKrkR9 0xxdpYZ6EGSTkMhINCYmVteuhyNINV1daYjVm8MMKr2VBp6P7TlNsu1RXKS1W4ioFc NMYLYWucWpSEG4v4B0yvyl73wp+7ToR5VnSe7q1E= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Xiang Mei , Weiming Shi , Allison Henderson , Jakub Kicinski , Sasha Levin Subject: [PATCH 7.0 135/378] net/rds: fix NULL deref in rds_ib_send_cqe_handler() on masked atomic completion Date: Tue, 16 Jun 2026 20:26:06 +0530 Message-ID: <20260616145117.408351326@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260616145109.744539446@linuxfoundation.org> References: <20260616145109.744539446@linuxfoundation.org> User-Agent: quilt/0.69 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 7.0-stable review patch. If anyone has any objections, please let me know. ------------------ From: Weiming Shi [ Upstream commit 34080db3e70ddf94c38512ad2331e3c3afca6cc1 ] rds_ib_xmit_atomic() always programs a masked atomic opcode (IB_WR_MASKED_ATOMIC_CMP_AND_SWP or IB_WR_MASKED_ATOMIC_FETCH_AND_ADD) for every RDS atomic cmsg. But the completion-side switch in rds_ib_send_unmap_op() only handles the non-masked opcodes, so a masked atomic completion falls through to default and returns rm == NULL while send->s_op is left set. rds_ib_send_cqe_handler() then dereferences the NULL rm via rm->m_final_op, oopsing in softirq context. An unprivileged AF_RDS sendmsg() of an atomic cmsg over an active RDS/IB connection triggers it; on hardware that natively accepts masked atomics (mlx4, mlx5) no extra setup is needed. RDS/IB: rds_ib_send_unmap_op: unexpected opcode 0xd in WR! Oops: general protection fault [#1] SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000190-0x0000000000000197] RIP: rds_ib_send_cqe_handler+0x25c/0xb10 (net/rds/ib_send.c:282) Call Trace: rds_ib_send_cqe_handler (net/rds/ib_send.c:282) poll_scq (net/rds/ib_cm.c:274) rds_ib_tasklet_fn_send (net/rds/ib_cm.c:294) tasklet_action_common (kernel/softirq.c:943) handle_softirqs (kernel/softirq.c:573) run_ksoftirqd (kernel/softirq.c:479) Kernel panic - not syncing: Fatal exception in interrupt Handle the masked atomic opcodes in the same case as the non-masked ones: they map to the same struct rds_message.atomic union member, so the existing container_of()/rds_ib_send_unmap_atomic() body is correct for them. Fixes: 20c72bd5f5f9 ("RDS: Implement masked atomic operations") Reported-by: Xiang Mei Signed-off-by: Weiming Shi Reviewed-by: Allison Henderson Link: https://patch.msgid.link/20260606192447.1179255-2-bestswngs@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/rds/ib_send.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/net/rds/ib_send.c b/net/rds/ib_send.c index fcd04c29f543e6..d6be95542119f6 100644 --- a/net/rds/ib_send.c +++ b/net/rds/ib_send.c @@ -170,6 +170,8 @@ static struct rds_message *rds_ib_send_unmap_op(struct rds_ib_connection *ic, break; case IB_WR_ATOMIC_FETCH_AND_ADD: case IB_WR_ATOMIC_CMP_AND_SWP: + case IB_WR_MASKED_ATOMIC_FETCH_AND_ADD: + case IB_WR_MASKED_ATOMIC_CMP_AND_SWP: if (send->s_op) { rm = container_of(send->s_op, struct rds_message, atomic); rds_ib_send_unmap_atomic(ic, send->s_op, wc_status); -- 2.53.0