kernel.git/drivers/net/xen-netback, branch linux-5.16.y

Revert "xen-netback: Check for hotplug-status existence before watching"

2022-03-16T13:26:48Z

[ Upstream commit e8240addd0a3919e0fd7436416afe9aa6429c484 ] This reverts commit 2afeec08ab5c86ae21952151f726bfe184f6b23d. The reasoning in the commit was wrong - the code expected to setup the watch even if 'hotplug-status' didn't exist. In fact, it relied on the watch being fired the first time - to check if maybe 'hotplug-status' is already set to 'connected'. Not registering a watch for non-existing path (which is the case if hotplug script hasn't been executed yet), made the backend not waiting for the hotplug script to execute. This in turns, made the netfront think the interface is fully operational, while in fact it was not (the vif interface on xen-netback side might not be configured yet). This was a workaround for 'hotplug-status' erroneously being removed. But since that is reverted now, the workaround is not necessary either. More discussion at https://lore.kernel.org/xen-devel/afedd7cb-a291-e773-8b0d-4db9b291fa98@ipxe.org/T/#u Signed-off-by: Marek Marczykowski-Górecki Reviewed-by: Paul Durrant Reviewed-by: Michael Brown Link: https://lore.kernel.org/r/20220222001817.2264967-2-marmarek@invisiblethingslab.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

Revert "xen-netback: remove 'hotplug-status' once it has served its purpose"

2022-03-16T13:26:48Z

[ Upstream commit 0f4558ae91870692ce7f509c31c9d6ee721d8cdc ] This reverts commit 1f2565780e9b7218cf92c7630130e82dcc0fe9c2. The 'hotplug-status' node should not be removed as long as the vif device remains configured. Otherwise the xen-netback would wait for re-running the network script even if it was already called (in case of the frontent re-connecting). But also, it _should_ be removed when the vif device is destroyed (for example when unbinding the driver) - otherwise hotplug script would not configure the device whenever it re-appear. Moving removal of the 'hotplug-status' node was a workaround for nothing calling network script after xen-netback module is reloaded. But when vif interface is re-created (on xen-netback unbind/bind for example), the script should be called, regardless of who does that - currently this case is not handled by the toolstack, and requires manual script call. Keeping hotplug-status=connected to skip the call is wrong and leads to not configured interface. More discussion at https://lore.kernel.org/xen-devel/afedd7cb-a291-e773-8b0d-4db9b291fa98@ipxe.org/T/#u Signed-off-by: Marek Marczykowski-Górecki Reviewed-by: Paul Durrant Link: https://lore.kernel.org/r/20220222001817.2264967-1-marmarek@invisiblethingslab.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

xen/netback: don't queue unlimited number of packages

2021-12-16T07:43:12Z

In case a guest isn't consuming incoming network traffic as fast as it is coming in, xen-netback is buffering network packages in unlimited numbers today. This can result in host OOM situations. Commit f48da8b14d04ca8 ("xen-netback: fix unlimited guest Rx internal queue and carrier flapping") meant to introduce a mechanism to limit the amount of buffered data by stopping the Tx queue when reaching the data limit, but this doesn't work for cases like UDP. When hitting the limit don't queue further SKBs, but drop them instead. In order to be able to tell Rx packages have been dropped increment the rx_dropped statistics counter in this case. It should be noted that the old solution to continue queueing SKBs had the additional problem of an overflow of the 32-bit rx_queue_len value would result in intermittent Tx queue enabling. This is part of XSA-392 Fixes: f48da8b14d04ca8 ("xen-netback: fix unlimited guest Rx internal queue and carrier flapping") Signed-off-by: Juergen Gross Reviewed-by: Jan Beulich

xen/netback: fix rx queue stall detection

2021-12-16T07:42:56Z

Commit 1d5d48523900a4b ("xen-netback: require fewer guest Rx slots when not using GSO") introduced a security problem in netback, as an interface would only be regarded to be stalled if no slot is available in the rx queue ring page. In case the SKB at the head of the queued requests will need more than one rx slot and only one slot is free the stall detection logic will never trigger, as the test for that is only looking for at least one slot to be free. Fix that by testing for the needed number of slots instead of only one slot being available. In order to not have to take the rx queue lock that often, store the number of needed slots in the queue data. As all SKB dequeue operations happen in the rx queue kernel thread this is safe, as long as the number of needed slots is accessed via READ/WRITE_ONCE() only and updates are always done with the rx queue lock held. Add a small helper for obtaining the number of free slots. This is part of XSA-392 Fixes: 1d5d48523900a4b ("xen-netback: require fewer guest Rx slots when not using GSO") Signed-off-by: Juergen Gross Reviewed-by: Jan Beulich

net: xen: use eth_hw_addr_set()

2021-10-22T17:15:54Z

Commit 406f42fa0d3c ("net-next: When a bond have a massive amount of VLANs...") introduced a rbtree for faster Ethernet address look up. To maintain netdev->dev_addr in this tree we need to make all the writes to it got through appropriate helpers. Signed-off-by: Jakub Kicinski

xen-netback: Remove redundant initialization of variable err

2021-10-15T10:02:36Z

The variable err is being initialized with a value that is never read, it is being updated immediately afterwards. The assignment is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King Signed-off-by: David S. Miller

xen-netback: correct success/error reporting for the SKB-with-fraglist case

2021-09-19T11:10:26Z

When re-entering the main loop of xenvif_tx_check_gop() a 2nd time, the special considerations for the head of the SKB no longer apply. Don't mistakenly report ERROR to the frontend for the first entry in the list, even if - from all I can tell - this shouldn't matter much as the overall transmit will need to be considered failed anyway. Signed-off-by: Jan Beulich Reviewed-by: Paul Durrant Signed-off-by: David S. Miller

xen-netback: take a reference to the RX task thread

2021-06-07T13:13:15Z

Do this in order to prevent the task from being freed if the thread returns (which can be triggered by the frontend) before the call to kthread_stop done as part of the backend tear down. Not taking the reference will lead to a use-after-free in that scenario. Such reference was taken before but dropped as part of the rework done in 2ac061ce97f4. Reintroduce the reference taking and add a comment this time explaining why it's needed. This is XSA-374 / CVE-2021-28691. Fixes: 2ac061ce97f4 ('xen/netback: cleanup init and deinit code') Signed-off-by: Roger Pau Monné Cc: stable@vger.kernel.org Reviewed-by: Jan Beulich Reviewed-by: Juergen Gross Signed-off-by: Juergen Gross

xen-netback: Check for hotplug-status existence before watching

2021-04-13T22:24:14Z

The logic in connect() is currently written with the assumption that xenbus_watch_pathfmt() will return an error for a node that does not exist. This assumption is incorrect: xenstore does allow a watch to be registered for a nonexistent node (and will send notifications should the node be subsequently created). As of commit 1f2565780 ("xen-netback: remove 'hotplug-status' once it has served its purpose"), this leads to a failure when a domU transitions into XenbusStateConnected more than once. On the first domU transition into Connected state, the "hotplug-status" node will be deleted by the hotplug_status_changed() callback in dom0. On the second or subsequent domU transition into Connected state, the hotplug_status_changed() callback will therefore never be invoked, and so the backend will remain stuck in InitWait. This failure prevents scenarios such as reloading the xen-netfront module within a domU, or booting a domU via iPXE. There is unfortunately no way for the domU to work around this dom0 bug. Fix by explicitly checking for existence of the "hotplug-status" node, thereby creating the behaviour that was previously assumed to exist. Signed-off-by: Michael Brown Reviewed-by: Paul Durrant Signed-off-by: David S. Miller

Merge git://git.kernel.org:/pub/scm/linux/kernel/git/netdev/net

2021-03-10T01:15:56Z

Pull networking fixes from David Miller: 1) Fix transmissions in dynamic SMPS mode in ath9k, from Felix Fietkau. 2) TX skb error handling fix in mt76 driver, also from Felix. 3) Fix BPF_FETCH atomic in x86 JIT, from Brendan Jackman. 4) Avoid double free of percpu pointers when freeing a cloned bpf prog. From Cong Wang. 5) Use correct printf format for dma_addr_t in ath11k, from Geert Uytterhoeven. 6) Fix resolve_btfids build with older toolchains, from Kun-Chuan Hsieh. 7) Don't report truncated frames to mac80211 in mt76 driver, from Lorenzop Bianconi. 8) Fix watcdog timeout on suspend/resume of stmmac, from Joakim Zhang. 9) mscc ocelot needs NET_DEVLINK selct in Kconfig, from Arnd Bergmann. 10) Fix sign comparison bug in TCP_ZEROCOPY_RECEIVE getsockopt(), from Arjun Roy. 11) Ignore routes with deleted nexthop object in mlxsw, from Ido Schimmel. 12) Need to undo tcp early demux lookup sometimes in nf_nat, from Florian Westphal. 13) Fix gro aggregation for udp encaps with zero csum, from Daniel Borkmann. 14) Make sure to always use imp*_ndo_send when necessaey, from Jason A. Donenfeld. 15) Fix TRSCER masks in sh_eth driver from Sergey Shtylyov. 16) prevent overly huge skb allocationsd in qrtr, from Pavel Skripkin. 17) Prevent rx ring copnsumer index loss of sync in enetc, from Vladimir Oltean. 18) Make sure textsearch copntrol block is large enough, from Wilem de Bruijn. 19) Revert MAC changes to r8152 leading to instability, from Hates Wang. 20) Advance iov in 9p even for empty reads, from Jissheng Zhang. 21) Double hook unregister in nftables, from PabloNeira Ayuso. 22) Fix memleak in ixgbe, fropm Dinghao Liu. 23) Avoid dups in pkt scheduler class dumps, from Maximilian Heyne. 24) Various mptcp fixes from Florian Westphal, Paolo Abeni, and Geliang Tang. 25) Fix DOI refcount bugs in cipso, from Paul Moore. 26) One too many irqsave in ibmvnic, from Junlin Yang. 27) Fix infinite loop with MPLS gso segmenting via virtio_net, from Balazs Nemeth. * git://git.kernel.org:/pub/scm/linux/kernel/git/netdev/net: (164 commits) s390/qeth: fix notification for pending buffers during teardown s390/qeth: schedule TX NAPI on QAOB completion s390/qeth: improve completion of pending TX buffers s390/qeth: fix memory leak after failed TX Buffer allocation net: avoid infinite loop in mpls_gso_segment when mpls_hlen == 0 net: check if protocol extracted by virtio_net_hdr_set_proto is correct net: dsa: xrs700x: check if partner is same as port in hsr join net: lapbether: Remove netif_start_queue / netif_stop_queue atm: idt77252: fix null-ptr-dereference atm: uPD98402: fix incorrect allocation atm: fix a typo in the struct description net: qrtr: fix error return code of qrtr_sendmsg() mptcp: fix length of ADD_ADDR with port sub-option net: bonding: fix error return code of bond_neigh_init() net: enetc: allow hardware timestamping on TX queues with tc-etf enabled net: enetc: set MAC RX FIFO to recommended value net: davicom: Use platform_get_irq_optional() net: davicom: Fix regulator not turned off on driver removal net: davicom: Fix regulator not turned off on failed probe net: dsa: fix switchdev objects on bridge master mistakenly being applied on ports ...