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 1CE8053A8A3; Wed, 23 Sep 2026 14:46:20 +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=1790174781; cv=none; b=rAuDH5fnnw73qkUipDVtQogYgbAQWU5SlYN4PyO5+QHKsPYHByFyO9Ct5yXwRIy32DtyT4AKoornOlpDLkeg1wfD5KmkKUEUZR1HSA2/lQ6sPVIYRCVR34hmtCKB71W/6/oBySFh7S6lni3+DMWMCFOt0NYkZVW9dpwv3J0+/9Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790174781; c=relaxed/simple; bh=P/jOioT9zfCS7+3wNn1YeN4hMd5Y+5j2LZqLsEafiuY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fj+2Q+F2hqYNVOIOJCFux1MnkZujOuNQ0b4kwY1Dp1BGXCstXXUMXdxc7CyT80jT/lVdoH33eouzqhnFBrJfS4dfHBGZTYFy6VBKsU6Pqiz+SjUhxlhF01IhJUlvYyY47QZDMa7qBnuWZn/GGTgk3ODPwO1myv+XkBbd8ZMN+N4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=gzcrYSTk; 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="gzcrYSTk" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 55FD81F000FF; Wed, 23 Sep 2026 14:46:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790174779; bh=7DM/X2ttHYyEykIoMuRiX75gJGW7gOkWhyaCg8cNpyk=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=gzcrYSTkQmLxUWl1lntipLqBzkuKOSIchRczIx1ylFfia2OVNIHGy0Z2+YFxPZvRl jFTWdp7mLySGE83vTGaCpIEkDuPzBtqlAuvo8l7S+SWPlR6n3b32tweA74ARG6Yukv Clh87TWBYDXIVdzwWS1aGuw1XNfqUqvcI0El6Ves= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+bd317784d628820741b5@syzkaller.appspotmail.com, Jeffin Philip , Leon Romanovsky Subject: [PATCH 6.18 223/398] RDMA/core: fix refcount bug in iwpm_get_nlmsg_request() Date: Wed, 23 Sep 2026 16:04:57 +0200 Message-ID: <20260923140649.201861142@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260923140643.441954610@linuxfoundation.org> References: <20260923140643.441954610@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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jeffin Philip commit 33fb59da49c4c3f5c2ec9f9d4447a56857a02c02 upstream. iwpm_get_nlmsg_request() initializes refcount _after_ list_add_tail() making it accessible to global list where another CPU can kref_get() on nlmsg_request causing a refcount "addition on 0" bug. Fix this by initializing kref _before_ list_add_tail() so refcount for nlmsg_request can be incremented/decremented normally. In addition, also initialize every field before list_add_tail(). Reported-by: syzbot+bd317784d628820741b5@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=bd317784d628820741b5 Fixes: 30dc5e63d6a5 ("RDMA/core: Add support for iWARP Port Mapper user space service") Cc: stable@vger.kernel.org Signed-off-by: Jeffin Philip Link: https://patch.msgid.link/20260904131437.12917-1-jeffinphilip14@gmail.com Signed-off-by: Leon Romanovsky Signed-off-by: Greg Kroah-Hartman --- drivers/infiniband/core/iwpm_util.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- a/drivers/infiniband/core/iwpm_util.c +++ b/drivers/infiniband/core/iwpm_util.c @@ -314,10 +314,6 @@ struct iwpm_nlmsg_request *iwpm_get_nlms if (!nlmsg_request) return NULL; - spin_lock_irqsave(&iwpm_nlmsg_req_lock, flags); - list_add_tail(&nlmsg_request->inprocess_list, &iwpm_nlmsg_req_list); - spin_unlock_irqrestore(&iwpm_nlmsg_req_lock, flags); - kref_init(&nlmsg_request->kref); kref_get(&nlmsg_request->kref); nlmsg_request->nlmsg_seq = nlmsg_seq; @@ -326,6 +322,11 @@ struct iwpm_nlmsg_request *iwpm_get_nlms nlmsg_request->err_code = 0; sema_init(&nlmsg_request->sem, 1); down(&nlmsg_request->sem); + + spin_lock_irqsave(&iwpm_nlmsg_req_lock, flags); + list_add_tail(&nlmsg_request->inprocess_list, &iwpm_nlmsg_req_list); + spin_unlock_irqrestore(&iwpm_nlmsg_req_lock, flags); + return nlmsg_request; }