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 D5A913A4508; Sat, 12 Sep 2026 07:05:34 +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=1789196736; cv=none; b=vErqjxkCkiPda+/1687RYRaDwKsFjjixCQJZ3Rhy1ZJZ/bSnfIcV59/EVY86k6xyRre0CLL5wyb+RLK/3RRMSRW9aGCvYODpcHDM31wdCB4z4a/uT2wFHeU7JhoChdNguuN7sz/c2YyI/LXn1FSKexhufC1wE/s4iBMIEyc45sg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789196736; c=relaxed/simple; bh=azk05WHO6V6GQXbGpKnr54h0cZetKBRRrCqPyj1iCFY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=aDMaw9jxvbo4t1miQ8c1dvLJr3ny8fB4iKMaMjekvIjIzCCS4pZCf2t0RSLVBk/N6zazuwhJ4leFeJuc1gkDOkHGZ7WjMD5InhXkguRKCsP4Turi+YvTIRHYdmF9LwITvcmVB4A8fWM/i633+reFprDWKNpIhFaswGhioQF7Zdc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=BzCFNQNQ; 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="BzCFNQNQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5E4F11F000FF; Sat, 12 Sep 2026 07:05:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789196733; bh=uI6gd4dQVZRvsOFcTmIlWF01O27WCQHdT+zNJJ5RHRs=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=BzCFNQNQOlzMPE1qTEMjVPNFaOog8EWALYdhSo6X5QhQrfyrkqqTqlVUZU7t8orTi ssqTzn746ZIRZrkyF04sYc4q1kmLp/6u0cn4sssi2mXTiD0XmjhPL2p3EaRgHQLJIz 60e9KPUlOQ5dwtqHOVwTXsrRGlteuwWfb5muCdy0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Li Chen , "Michael S. Tsirkin" , Sasha Levin Subject: [PATCH 7.2 0026/1815] nvdimm: virtio_pmem: refcount requests for token lifetime Date: Sat, 12 Sep 2026 08:29:36 +0200 Message-ID: <20260912065649.621450405@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065648.999753832@linuxfoundation.org> References: <20260912065648.999753832@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 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Li Chen [ Upstream commit e57140944b5a47a7fd5a142faab29a02af040bc8 ] KASAN reports slab-use-after-free in __wake_up_common(): BUG: KASAN: slab-use-after-free in __wake_up_common+0x114/0x160 Read of size 8 at addr ffff88810fdcb710 by task swapper/0/0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.19.0-next-20260220-00006-g1eae5f204ec3 #4 PREEMPT(full) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.17.0-2-2 04/01/2014 Call Trace: dump_stack_lvl+0x6d/0xb0 print_report+0x170/0x4e2 ? __pfx__raw_spin_lock_irqsave+0x10/0x10 ? __virt_addr_valid+0x1dc/0x380 kasan_report+0xbc/0xf0 ? __wake_up_common+0x114/0x160 ? __wake_up_common+0x114/0x160 __wake_up_common+0x114/0x160 ? __pfx__raw_spin_lock_irqsave+0x10/0x10 __wake_up+0x36/0x60 virtio_pmem_host_ack+0x11d/0x3b0 ? sched_balance_domains+0x29f/0xb00 ? __pfx_virtio_pmem_host_ack+0x10/0x10 ? _raw_spin_lock_irqsave+0x98/0x100 ? __pfx__raw_spin_lock_irqsave+0x10/0x10 vring_interrupt+0x1c9/0x5e0 ? __pfx_vp_interrupt+0x10/0x10 vp_vring_interrupt+0x87/0x100 ? __pfx_vp_interrupt+0x10/0x10 __handle_irq_event_percpu+0x17f/0x550 ? __pfx__raw_spin_lock+0x10/0x10 handle_irq_event+0xab/0x1c0 handle_fasteoi_irq+0x276/0xae0 __common_interrupt+0x65/0x130 common_interrupt+0x78/0xa0 virtio_pmem_host_ack() wakes a request that has already been freed by the submitter. This happens when the request token is still reachable via the virtqueue, but virtio_pmem_flush() returns and frees it. Fix the token lifetime by refcounting struct virtio_pmem_request. virtio_pmem_flush() holds a submitter reference, and the virtqueue holds an extra reference once the request is queued. The completion path drops the virtqueue reference, and the submitter drops its reference before returning. Fixes: 6e84200c0a29 ("virtio-pmem: Add virtio pmem driver") Cc: stable@vger.kernel.org Signed-off-by: Li Chen Signed-off-by: Michael S. Tsirkin Message-ID: <20260630092338.2094628-9-me@linux.beauty> Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/nvdimm/nd_virtio.c | 32 ++++++++++++++++++++++++++++---- drivers/nvdimm/virtio_pmem.h | 2 ++ 2 files changed, 30 insertions(+), 4 deletions(-) --- a/drivers/nvdimm/nd_virtio.c +++ b/drivers/nvdimm/nd_virtio.c @@ -15,6 +15,14 @@ struct virtio_pmem_flush_work { struct bio *bio; }; +static void virtio_pmem_req_release(struct kref *kref) +{ + struct virtio_pmem_request *req; + + req = container_of(kref, struct virtio_pmem_request, kref); + kfree(req); +} + static void virtio_pmem_wake_one_waiter(struct virtio_pmem *vpmem) { struct virtio_pmem_request *req_buf; @@ -42,6 +50,7 @@ void virtio_pmem_host_ack(struct virtque virtio_pmem_wake_one_waiter(vpmem); WRITE_ONCE(req_data->done, true); wake_up(&req_data->host_acked); + kref_put(&req_data->kref, virtio_pmem_req_release); } spin_unlock_irqrestore(&vpmem->pmem_lock, flags); } @@ -72,6 +81,7 @@ static int virtio_pmem_flush(struct nd_r if (!req_data) return -ENOMEM; + kref_init(&req_data->kref); WRITE_ONCE(req_data->done, false); init_waitqueue_head(&req_data->host_acked); init_waitqueue_head(&req_data->wq_buf); @@ -89,10 +99,23 @@ static int virtio_pmem_flush(struct nd_r * to req_list and wait for host_ack to wake us up when free * slots are available. */ - while ((err = virtqueue_add_sgs(vpmem->req_vq, sgs, 1, 1, req_data, - GFP_ATOMIC)) == -ENOSPC) { + for (;;) { + err = virtqueue_add_sgs(vpmem->req_vq, sgs, 1, 1, req_data, + GFP_ATOMIC); + if (!err) { + /* + * Take the virtqueue reference while @pmem_lock is + * held so completion cannot run concurrently. + */ + kref_get(&req_data->kref); + break; + } + + if (err != -ENOSPC) + break; - dev_info(&vdev->dev, "failed to send command to virtio pmem device, no free slots in the virtqueue\n"); + dev_info_ratelimited(&vdev->dev, + "failed to send command to virtio pmem device, no free slots in the virtqueue\n"); WRITE_ONCE(req_data->wq_buf_avail, false); list_add_tail(&req_data->list, &vpmem->req_list); spin_unlock_irqrestore(&vpmem->pmem_lock, flags); @@ -101,6 +124,7 @@ static int virtio_pmem_flush(struct nd_r wait_event(req_data->wq_buf, READ_ONCE(req_data->wq_buf_avail)); spin_lock_irqsave(&vpmem->pmem_lock, flags); } + err1 = virtqueue_kick(vpmem->req_vq); spin_unlock_irqrestore(&vpmem->pmem_lock, flags); /* @@ -116,7 +140,7 @@ static int virtio_pmem_flush(struct nd_r err = le32_to_cpu(req_data->resp.ret); } - kfree(req_data); + kref_put(&req_data->kref, virtio_pmem_req_release); return err; }; --- a/drivers/nvdimm/virtio_pmem.h +++ b/drivers/nvdimm/virtio_pmem.h @@ -12,12 +12,14 @@ #include #include +#include #include #include #include #include struct virtio_pmem_request { + struct kref kref; struct virtio_pmem_req req; struct virtio_pmem_resp resp;