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 42975261B71; Tue, 28 Jul 2026 01:00:09 +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=1785200412; cv=none; b=ECbCqRmSwhG4ZE09FHUSykibMXnlaffR0NYwFfEDDjeSRrsExVxdWANe2/Vqq6Ahrbfc6nUcsy9Vd+W04zfSD7zv3NXVXkOD2TZxevHs4HTV2MhsikQy1JIC/+qEHtCGEFT5h/FBgy0ho+wNyETb4WlUp7uVjeF3foycisRv+gQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785200412; c=relaxed/simple; bh=GUtkgyKZMUl6G82wFhtKPCd2IRFRABAkNgX+wlmUKOU=; h=Date:To:From:Subject:Message-Id; b=P85Q6Q06IRJn23AdpZ52BFih+puTQS/mV4H7e1PXpKbPFYbG/uOweLS5wY1aameCIZg6awp/pbJ4LOL63QLo8AYx1VVwhphgurx5hp/SoPrGmqmuoEcMxvUOhcE7xA03+p5IJR6j110Dy2Hm8C1pSDVaOE9xsPQM3ERGSAJAZ78= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=1LCNS/4m; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="1LCNS/4m" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0F5411F000E9; Tue, 28 Jul 2026 01:00:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1785200409; bh=+ekvYRaDcrAeZfAF0V4F4da5Dnh+gWmswDQ7EKDu5TA=; h=Date:To:From:Subject; b=1LCNS/4m1edEh4NeChLcbxLUx0qUtqqPml2KX4ku15YDj6yDsNCKAh5NAga/A5aTn 1PRTWUhaeZrV2VaaQDNdmNvHrWA6Xh6iB+8fyRaGTiueCaroMnHCADcDmkZrZpb/Wt Zl4yJXJV5AteoSNTKFvrJJcbDaT07AzOn6GDBVH8= Date: Mon, 27 Jul 2026 18:00:08 -0700 To: mm-commits@vger.kernel.org,stable@vger.kernel.org,mporter@kernel.crashing.org,gregkh@linuxfoundation.org,error27@gmail.com,alex.bou9@gmail.com,james010kim@gmail.com,akpm@linux-foundation.org From: Andrew Morton Subject: + rapidio-mport_cdev-fix-use-after-free-in-dma_req_free.patch added to mm-nonmm-unstable branch Message-Id: <20260728010009.0F5411F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: rapidio: mport_cdev: fix use-after-free in dma_req_free() has been added to the -mm mm-nonmm-unstable branch. Its filename is rapidio-mport_cdev-fix-use-after-free-in-dma_req_free.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/rapidio-mport_cdev-fix-use-after-free-in-dma_req_free.patch This patch will later appear in the mm-nonmm-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: James Kim Subject: rapidio: mport_cdev: fix use-after-free in dma_req_free() Date: Fri, 24 Jul 2026 08:52:20 +0900 dma_req_free() acquires buf_mutex through req->map, drops the mapping reference with kref_put(), and then dereferences req->map again to unlock the mutex. If kref_put() drops the last reference, mport_release_mapping() frees the mapping, and the subsequent mutex_unlock() dereferences a freed object. This is a use-after-free. Fix this by caching map and md before kref_put(), clearing req->map while holding buf_mutex, and using the cached md for mutex unlocking. The bug is reachable from userspace via the RapidIO mport character device interface. Link: https://lore.kernel.org/20260723235220.588424-1-james010kim@gmail.com Fixes: e8de370188d0 ("rapidio: add mport char device driver") Signed-off-by: James Kim Reviewed-by: Dan Carpenter Cc: Alexandre Bounine Cc: Greg Kroah-Hartman Cc: Matt Porter Cc: Signed-off-by: Andrew Morton --- drivers/rapidio/devices/rio_mport_cdev.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) --- a/drivers/rapidio/devices/rio_mport_cdev.c~rapidio-mport_cdev-fix-use-after-free-in-dma_req_free +++ a/drivers/rapidio/devices/rio_mport_cdev.c @@ -564,9 +564,13 @@ static void dma_req_free(struct kref *re } if (req->map) { - mutex_lock(&req->map->md->buf_mutex); - kref_put(&req->map->ref, mport_release_mapping); - mutex_unlock(&req->map->md->buf_mutex); + struct rio_mport_mapping *map = req->map; + struct mport_dev *md = map->md; + + mutex_lock(&md->buf_mutex); + req->map = NULL; + kref_put(&map->ref, mport_release_mapping); + mutex_unlock(&md->buf_mutex); } kref_put(&priv->dma_ref, mport_release_dma); _ Patches currently in -mm which might be from james010kim@gmail.com are rapidio-mport_cdev-fix-use-after-free-in-dma_req_free.patch