kernel/linux.git/drivers/net/virtio_net.c, branch v5.19

virtio-net: fix the race between refill work and close

2022-07-27T12:20:44+00:00

We try using cancel_delayed_work_sync() to prevent the work from enabling NAPI. This is insufficient since we don't disable the source of the refill work scheduling. This means an NAPI poll callback after cancel_delayed_work_sync() can schedule the refill work then can re-enable the NAPI that leads to use-after-free [1]. Since the work can enable NAPI, we can't simply disable NAPI before calling cancel_delayed_work_sync(). So fix this by introducing a dedicated boolean to control whether or not the work could be scheduled from NAPI. [1] ================================================================== BUG: KASAN: use-after-free in refill_work+0x43/0xd4 Read of size 2 at addr ffff88810562c92e by task kworker/2:1/42 CPU: 2 PID: 42 Comm: kworker/2:1 Not tainted 5.19.0-rc1+ #480 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Workqueue: events refill_work Call Trace: dump_stack_lvl+0x34/0x44 print_report.cold+0xbb/0x6ac ? _printk+0xad/0xde ? refill_work+0x43/0xd4 kasan_report+0xa8/0x130 ? refill_work+0x43/0xd4 refill_work+0x43/0xd4 process_one_work+0x43d/0x780 worker_thread+0x2a0/0x6f0 ? process_one_work+0x780/0x780 kthread+0x167/0x1a0 ? kthread_exit+0x50/0x50 ret_from_fork+0x22/0x30 ... Fixes: b2baed69e605c ("virtio_net: set/cancel work on ndo_open/ndo_stop") Signed-off-by: Jason Wang Acked-by: Michael S. Tsirkin Reviewed-by: Xuan Zhuo Signed-off-by: David S. Miller

Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

2022-06-27T17:47:34+00:00

Pull virtio fixes from Michael Tsirkin: "Fixes all over the place, most notably we are disabling IRQ hardening (again!)" * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: virtio_ring: make vring_create_virtqueue_split prettier vhost-vdpa: call vhost_vdpa_cleanup during the release virtio_mmio: Restore guest page size on resume virtio_mmio: Add missing PM calls to freeze/restore caif_virtio: fix race between virtio_device_ready() and ndo_open() virtio-net: fix race between ndo_open() and virtio_device_ready() virtio: disable notification hardening by default virtio: Remove unnecessary variable assignments virtio_ring : keep used_wrap_counter in vq->last_used_idx vduse: Tie vduse mgmtdev and its device vdpa/mlx5: Initialize CVQ vringh only once vdpa/mlx5: Update Control VQ callback information

virtio-net: fix race between ndo_open() and virtio_device_ready()

2022-06-27T12:02:59+00:00

We currently call virtio_device_ready() after netdev registration. Since ndo_open() can be called immediately after register_netdev, this means there exists a race between ndo_open() and virtio_device_ready(): the driver may start to use the device before DRIVER_OK which violates the spec. Fix this by switching to use register_netdevice() and protect the virtio_device_ready() with rtnl_lock() to make sure ndo_open() can only be called after virtio_device_ready(). Fixes: 4baf1e33d0842 ("virtio_net: enable VQs early") Signed-off-by: Jason Wang Message-Id: <20220617072949.30734-1-jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin

virtio_net: fix xdp_rxq_info bug after suspend/resume

2022-06-23T02:09:13+00:00

The following sequence currently causes a driver bug warning when using virtio_net: # ip link set eth0 up # echo mem > /sys/power/state (or e.g. # rtcwake -s 10 -m mem) # ip link set eth0 down Missing register, driver bug WARNING: CPU: 0 PID: 375 at net/core/xdp.c:138 xdp_rxq_info_unreg+0x58/0x60 Call trace: xdp_rxq_info_unreg+0x58/0x60 virtnet_close+0x58/0xac __dev_close_many+0xac/0x140 __dev_change_flags+0xd8/0x210 dev_change_flags+0x24/0x64 do_setlink+0x230/0xdd0 ... This happens because virtnet_freeze() frees the receive_queue completely (including struct xdp_rxq_info) but does not call xdp_rxq_info_unreg(). Similarly, virtnet_restore() sets up the receive_queue again but does not call xdp_rxq_info_reg(). Actually, parts of virtnet_freeze_down() and virtnet_restore_up() are almost identical to virtnet_close() and virtnet_open(): only the calls to xdp_rxq_info_(un)reg() are missing. This means that we can fix this easily and avoid such problems in the future by just calling virtnet_close()/open() from the freeze/restore handlers. Aside from adding the missing xdp_rxq_info calls the only difference is that the refill work is only cancelled if netif_running(). However, this should not make any functional difference since the refill work should only be active if the network interface is actually up. Fixes: 754b8a21a96d ("virtio_net: setup xdp_rxq_info") Signed-off-by: Stephan Gerhold Acked-by: Jesper Dangaard Brouer Acked-by: Jason Wang Link: https://lore.kernel.org/r/20220621114845.3650258-1-stephan.gerhold@kernkonzept.com Signed-off-by: Jakub Kicinski

net: virtio: switch to netif_napi_add_weight()

2022-05-08T10:33:57+00:00

virtio netdev driver uses a custom napi weight, switch to the new API for setting custom weight. Signed-off-by: Jakub Kicinski Reviewed-by: Xuan Zhuo Acked-by: Jason Wang Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller

net: move snowflake callers to netif_napi_add_tx_weight()

2022-05-05T22:54:18+00:00

Make the drivers with custom tx napi weight call netif_napi_add_tx_weight(). Reviewed-by: Xuan Zhuo Link: https://lore.kernel.org/r/20220504163725.550782-2-kuba@kernel.org Signed-off-by: Jakub Kicinski

virtio_net: fix wrong buf address calculation when using xdp

2022-04-26T11:24:44+00:00

We received a report[1] of kernel crashes when Cilium is used in XDP mode with virtio_net after updating to newer kernels. After investigating the reason it turned out that when using mergeable bufs with an XDP program which adjusts xdp.data or xdp.data_meta page_to_buf() calculates the build_skb address wrong because the offset can become less than the headroom so it gets the address of the previous page (-X bytes depending on how lower offset is): page_to_skb: page addr ffff9eb2923e2000 buf ffff9eb2923e1ffc offset 252 headroom 256 This is a pr_err() I added in the beginning of page_to_skb which clearly shows offset that is less than headroom by adding 4 bytes of metadata via an xdp prog. The calculations done are: receive_mergeable(): headroom = VIRTIO_XDP_HEADROOM; // VIRTIO_XDP_HEADROOM == 256 bytes offset = xdp.data - page_address(xdp_page) - vi->hdr_len - metasize; page_to_skb(): p = page_address(page) + offset; ... buf = p - headroom; Now buf goes -4 bytes from the page's starting address as can be seen above which is set as skb->head and skb->data by build_skb later. Depending on what's done with the skb (when it's freed most often) we get all kinds of corruptions and BUG_ON() triggers in mm[2]. We have to recalculate the new headroom after the xdp program has run, similar to how offset and len are recalculated. Headroom is directly related to data_hard_start, data and data_meta, so we use them to get the new size. The result is correct (similar pr_err() in page_to_skb, one case of xdp_page and one case of virtnet buf): a) Case with 4 bytes of metadata [ 115.949641] page_to_skb: page addr ffff8b4dcfad2000 offset 252 headroom 252 [ 121.084105] page_to_skb: page addr ffff8b4dcf018000 offset 20732 headroom 252 b) Case of pushing data +32 bytes [ 153.181401] page_to_skb: page addr ffff8b4dd0c4d000 offset 288 headroom 288 [ 158.480421] page_to_skb: page addr ffff8b4dd00b0000 offset 24864 headroom 288 c) Case of pushing data -33 bytes [ 835.906830] page_to_skb: page addr ffff8b4dd3270000 offset 223 headroom 223 [ 840.839910] page_to_skb: page addr ffff8b4dcdd68000 offset 12511 headroom 223 Offset and headroom are equal because offset points to the start of reserved bytes for the virtio_net header which are at buf start + headroom, while data points at buf start + vnet hdr size + headroom so when data or data_meta are adjusted by the xdp prog both the headroom size and the offset change equally. We can use data_hard_start to compute the new headroom after the xdp prog (linearized / page start case, the virtnet buf case is similar just with bigger base offset): xdp.data_hard_start = page_address + vnet_hdr xdp.data = page_address + vnet_hdr + headroom new headroom after xdp prog = xdp.data - xdp.data_hard_start - metasize An example reproducer xdp prog[3] is below. [1] https://github.com/cilium/cilium/issues/19453 [2] Two of the many traces: [ 40.437400] BUG: Bad page state in process swapper/0 pfn:14940 [ 40.916726] BUG: Bad page state in process systemd-resolve pfn:053b7 [ 41.300891] kernel BUG at include/linux/mm.h:720! [ 41.301801] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI [ 41.302784] CPU: 1 PID: 1181 Comm: kubelet Kdump: loaded Tainted: G B W 5.18.0-rc1+ #37 [ 41.304458] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1.fc35 04/01/2014 [ 41.306018] RIP: 0010:page_frag_free+0x79/0xe0 [ 41.306836] Code: 00 00 75 ea 48 8b 07 a9 00 00 01 00 74 e0 48 8b 47 48 48 8d 50 ff a8 01 48 0f 45 fa eb d0 48 c7 c6 18 b8 30 a6 e8 d7 f8 fc ff <0f> 0b 48 8d 78 ff eb bc 48 8b 07 a9 00 00 01 00 74 3a 66 90 0f b6 [ 41.310235] RSP: 0018:ffffac05c2a6bc78 EFLAGS: 00010292 [ 41.311201] RAX: 000000000000003e RBX: 0000000000000000 RCX: 0000000000000000 [ 41.312502] RDX: 0000000000000001 RSI: ffffffffa6423004 RDI: 00000000ffffffff [ 41.313794] RBP: ffff993c98823600 R08: 0000000000000000 R09: 00000000ffffdfff [ 41.315089] R10: ffffac05c2a6ba68 R11: ffffffffa698ca28 R12: ffff993c98823600 [ 41.316398] R13: ffff993c86311ebc R14: 0000000000000000 R15: 000000000000005c [ 41.317700] FS: 00007fe13fc56740(0000) GS:ffff993cdd900000(0000) knlGS:0000000000000000 [ 41.319150] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 41.320152] CR2: 000000c00008a000 CR3: 0000000014908000 CR4: 0000000000350ee0 [ 41.321387] Call Trace: [ 41.321819] [ 41.322193] skb_release_data+0x13f/0x1c0 [ 41.322902] __kfree_skb+0x20/0x30 [ 41.343870] tcp_recvmsg_locked+0x671/0x880 [ 41.363764] tcp_recvmsg+0x5e/0x1c0 [ 41.384102] inet_recvmsg+0x42/0x100 [ 41.406783] ? sock_recvmsg+0x1d/0x70 [ 41.428201] sock_read_iter+0x84/0xd0 [ 41.445592] ? 0xffffffffa3000000 [ 41.462442] new_sync_read+0x148/0x160 [ 41.479314] ? 0xffffffffa3000000 [ 41.496937] vfs_read+0x138/0x190 [ 41.517198] ksys_read+0x87/0xc0 [ 41.535336] do_syscall_64+0x3b/0x90 [ 41.551637] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 41.568050] RIP: 0033:0x48765b [ 41.583955] Code: e8 4a 35 fe ff eb 88 cc cc cc cc cc cc cc cc e8 fb 7a fe ff 48 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 28 ff ff ff ff 48 c7 44 24 30 [ 41.632818] RSP: 002b:000000c000a2f5b8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000 [ 41.664588] RAX: ffffffffffffffda RBX: 000000c000062000 RCX: 000000000048765b [ 41.681205] RDX: 0000000000005e54 RSI: 000000c000e66000 RDI: 0000000000000016 [ 41.697164] RBP: 000000c000a2f608 R08: 0000000000000001 R09: 00000000000001b4 [ 41.713034] R10: 00000000000000b6 R11: 0000000000000212 R12: 00000000000000e9 [ 41.728755] R13: 0000000000000001 R14: 000000c000a92000 R15: ffffffffffffffff [ 41.744254] [ 41.758585] Modules linked in: br_netfilter bridge veth netconsole virtio_net and [ 33.524802] BUG: Bad page state in process systemd-network pfn:11e60 [ 33.528617] page ffffe05dc0147b00 ffffe05dc04e7a00 ffff8ae9851ec000 (1) len 82 offset 252 metasize 4 hroom 0 hdr_len 12 data ffff8ae9851ec10c data_meta ffff8ae9851ec108 data_end ffff8ae9851ec14e [ 33.529764] page:000000003792b5ba refcount:0 mapcount:-512 mapping:0000000000000000 index:0x0 pfn:0x11e60 [ 33.532463] flags: 0xfffffc0000000(node=0|zone=1|lastcpupid=0x1fffff) [ 33.532468] raw: 000fffffc0000000 0000000000000000 dead000000000122 0000000000000000 [ 33.532470] raw: 0000000000000000 0000000000000000 00000000fffffdff 0000000000000000 [ 33.532471] page dumped because: nonzero mapcount [ 33.532472] Modules linked in: br_netfilter bridge veth netconsole virtio_net [ 33.532479] CPU: 0 PID: 791 Comm: systemd-network Kdump: loaded Not tainted 5.18.0-rc1+ #37 [ 33.532482] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1.fc35 04/01/2014 [ 33.532484] Call Trace: [ 33.532496] [ 33.532500] dump_stack_lvl+0x45/0x5a [ 33.532506] bad_page.cold+0x63/0x94 [ 33.532510] free_pcp_prepare+0x290/0x420 [ 33.532515] free_unref_page+0x1b/0x100 [ 33.532518] skb_release_data+0x13f/0x1c0 [ 33.532524] kfree_skb_reason+0x3e/0xc0 [ 33.532527] ip6_mc_input+0x23c/0x2b0 [ 33.532531] ip6_sublist_rcv_finish+0x83/0x90 [ 33.532534] ip6_sublist_rcv+0x22b/0x2b0 [3] XDP program to reproduce(xdp_pass.c): #include #include SEC("xdp_pass") int xdp_pkt_pass(struct xdp_md *ctx) { bpf_xdp_adjust_head(ctx, -(int)32); return XDP_PASS; } char _license[] SEC("license") = "GPL"; compile: clang -O2 -g -Wall -target bpf -c xdp_pass.c -o xdp_pass.o load on virtio_net: ip link set enp1s0 xdpdrv obj xdp_pass.o sec xdp_pass CC: stable@vger.kernel.org CC: Jason Wang CC: Xuan Zhuo CC: Daniel Borkmann CC: "Michael S. Tsirkin" CC: virtualization@lists.linux-foundation.org Fixes: 8fb7da9e9907 ("virtio_net: get build_skb() buf by data ptr") Signed-off-by: Nikolay Aleksandrov Reviewed-by: Xuan Zhuo Acked-by: Daniel Borkmann Acked-by: Michael S. Tsirkin Acked-by: Jason Wang Link: https://lore.kernel.org/r/20220425103703.3067292-1-razor@blackwall.org Signed-off-by: Paolo Abeni

Merge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost

2022-03-31T20:57:15+00:00

Pull virtio updates from Michael Tsirkin: - vdpa generic device type support - more virtio hardening for broken devices (but on the same theme, revert some virtio hotplug hardening patches - they were misusing some interrupt flags and had to be reverted) - RSS support in virtio-net - max device MTU support in mlx5 vdpa - akcipher support in virtio-crypto - shared IRQ support in ifcvf vdpa - a minor performance improvement in vhost - enable virtio mem for ARM64 - beginnings of advance dma support - cleanups, fixes all over the place * tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost: (33 commits) vdpa/mlx5: Avoid processing works if workqueue was destroyed vhost: handle error while adding split ranges to iotlb vdpa: support exposing the count of vqs to userspace vdpa: change the type of nvqs to u32 vdpa: support exposing the config size to userspace vdpa/mlx5: re-create forwarding rules after mac modified virtio: pci: check bar values read from virtio config space Revert "virtio_pci: harden MSI-X interrupts" Revert "virtio-pci: harden INTX interrupts" drivers/net/virtio_net: Added RSS hash report control. drivers/net/virtio_net: Added RSS hash report. drivers/net/virtio_net: Added basic RSS support. drivers/net/virtio_net: Fixed padded vheader to use v1 with hash. virtio: use virtio_device_ready() in virtio_device_restore() tools/virtio: compile with -pthread tools/virtio: fix after premapped buf support virtio_ring: remove flags check for unmap packed indirect desc virtio_ring: remove flags check for unmap split indirect desc virtio_ring: rename vring_unmap_state_packed() to vring_unmap_extra_packed() net/mlx5: Add support for configuring max device MTU ...

drivers/net/virtio_net: Added RSS hash report control.

2022-03-28T20:52:59+00:00

Now it's possible to control supported hashflows. Added hashflow set/get callbacks. Also, disabling RXH_IP_SRC/DST for TCP would disable then for UDP. TCP and UDP supports only: ethtool -U eth0 rx-flow-hash tcp4 sd RXH_IP_SRC + RXH_IP_DST ethtool -U eth0 rx-flow-hash tcp4 sdfn RXH_IP_SRC + RXH_IP_DST + RXH_L4_B_0_1 + RXH_L4_B_2_3 Disabling happens because VirtioNET hashtype for IP doesn't check L4 proto, it works for all IP packets(TCP, UDP, ICMP, etc.). For TCP and UDP, it's possible to set IP+PORT hashes. But disabling IP hashes will disable them for TCP and UDP simultaneously. It's possible to set IP+PORT for TCP/UDP and disable/enable IP for everything else(UDP, ICMP, etc.). Signed-off-by: Andrew Melnychenko Link: https://lore.kernel.org/r/20220328175336.10802-5-andrew@daynix.com Signed-off-by: Michael S. Tsirkin

drivers/net/virtio_net: Added RSS hash report.

2022-03-28T20:52:59+00:00

Added features for RSS hash report. If hash is provided - it sets to skb. Added checks if rss and/or hash are enabled together. Signed-off-by: Andrew Melnychenko Link: https://lore.kernel.org/r/20220328175336.10802-4-andrew@daynix.com Signed-off-by: Michael S. Tsirkin