[Group.of.nepali.translators] [Bug 1840619] Re: skb_warn_bad_offload kernel splat due to CHECKSUM target not compatible with GSO skbs
This bug was fixed in the package linux - 4.4.0-165.193 --- linux (4.4.0-165.193) xenial; urgency=medium * xenial/linux: 4.4.0-165.193 -proposed tracker (LP: #1844416) * Xenial update: 4.4.187 upstream stable release (LP: #1840081) - MIPS: ath79: fix ar933x uart parity mode - MIPS: fix build on non-linux hosts - dmaengine: imx-sdma: fix use-after-free on probe error path - ath10k: Do not send probe response template for mesh - ath9k: Check for errors when reading SREV register - ath6kl: add some bounds checking - ath: DFS JP domain W56 fixed pulse type 3 RADAR detection - batman-adv: fix for leaked TVLV handler. - media: dvb: usb: fix use after free in dvb_usb_device_exit - crypto: talitos - fix skcipher failure due to wrong output IV - media: marvell-ccic: fix DMA s/g desc number calculation - media: vpss: fix a potential NULL pointer dereference - net: stmmac: dwmac1000: Clear unused address entries - signal/pid_namespace: Fix reboot_pid_ns to use send_sig not force_sig - af_key: fix leaks in key_pol_get_resp and dump_sp. - xfrm: Fix xfrm sel prefix length validation - media: staging: media: davinci_vpfe: - Fix for memory leak if decoder initialization fails. - net: phy: Check against net_device being NULL - tua6100: Avoid build warnings. - locking/lockdep: Fix merging of hlocks with non-zero references - media: wl128x: Fix some error handling in fm_v4l2_init_video_device() - cpupower : frequency-set -r option misses the last cpu in related cpu list - net: fec: Do not use netdev messages too early - net: axienet: Fix race condition causing TX hang - s390/qdio: handle PENDING state for QEBSM devices - perf test 6: Fix missing kvm module load for s390 - gpio: omap: fix lack of irqstatus_raw0 for OMAP4 - gpio: omap: ensure irq is enabled before wakeup - regmap: fix bulk writes on paged registers - bpf: silence warning messages in core - rcu: Force inlining of rcu_read_lock() - xfrm: fix sa selector validation - perf evsel: Make perf_evsel__name() accept a NULL argument - vhost_net: disable zerocopy by default - EDAC/sysfs: Fix memory leak when creating a csrow object - media: i2c: fix warning same module names - ntp: Limit TAI-UTC offset - timer_list: Guard procfs specific code - acpi/arm64: ignore 5.1 FADTs that are reported as 5.0 - media: coda: fix mpeg2 sequence number handling - media: coda: increment sequence offset for the last returned frame - mt7601u: do not schedule rx_tasklet when the device has been disconnected - x86/build: Add 'set -e' to mkcapflags.sh to delete broken capflags.c - mt7601u: fix possible memory leak when the device is disconnected - ath10k: fix PCIE device wake up failed - rslib: Fix decoding of shortened codes - rslib: Fix handling of of caller provided syndrome - ixgbe: Check DDM existence in transceiver before access - EDAC: Fix global-out-of-bounds write when setting edac_mc_poll_msec - bcache: check c->gc_thread by IS_ERR_OR_NULL in cache_set_flush() - Bluetooth: hci_bcsp: Fix memory leak in rx_skb - Bluetooth: 6lowpan: search for destination address in all peers - Bluetooth: Check state in l2cap_disconnect_rsp - Bluetooth: validate BLE connection interval updates - crypto: ghash - fix unaligned memory access in ghash_setkey() - crypto: arm64/sha1-ce - correct digest for empty data in finup - crypto: arm64/sha2-ce - correct digest for empty data in finup - Input: gtco - bounds check collection indent level - regulator: s2mps11: Fix buck7 and buck8 wrong voltages - tracing/snapshot: Resize spare buffer if size changed - NFSv4: Handle the special Linux file open access mode - lib/scatterlist: Fix mapping iterator when sg->offset is greater than PAGE_SIZE - ALSA: seq: Break too long mutex context in the write loop - media: v4l2: Test type instead of cfg->type in v4l2_ctrl_new_custom() - media: coda: Remove unbalanced and unneeded mutex unlock - KVM: x86/vPMU: refine kvm_pmu err msg when event creation failed - drm/nouveau/i2c: Enable i2c pads & busses during preinit - padata: use smp_mb in padata_reorder to avoid orphaned padata jobs - 9p/virtio: Add cleanup path in p9_virtio_init - PCI: Do not poll for PME if the device is in D3cold - take floppy compat ioctls to sodding floppy.c - floppy: fix out-of-bounds read in next_valid_format - floppy: fix invalid pointer dereference in drive_name - coda: pass the host file in vma->vm_file on mmap - gpu: ipu-v3: ipu-ic: Fix saturation bit offset in TPMEM - parisc: Fix kernel panic due invalid values in IAOQ0 or IAOQ1 - powerpc/32s: fix suspend/resume when IBATs 4-7 are used - powerpc/watchpoint: Restore NV GPRs while returning from exception - eCryptfs: fix a couple type promotion bugs -
[Group.of.nepali.translators] [Bug 1840619] Re: skb_warn_bad_offload kernel splat due to CHECKSUM target not compatible with GSO skbs
** Changed in: linux (Ubuntu) Status: Incomplete => Fix Released -- You received this bug notification because you are a member of नेपाली भाषा समायोजकहरुको समूह, which is subscribed to Xenial. Matching subscriptions: Ubuntu 16.04 Bugs https://bugs.launchpad.net/bugs/1840619 Title: skb_warn_bad_offload kernel splat due to CHECKSUM target not compatible with GSO skbs Status in linux package in Ubuntu: Fix Released Status in linux source package in Xenial: In Progress Bug description: BugLink: https://bugs.launchpad.net/bugs/1840619 [Impact] In environments which have CHECKSUM iptables rules set, the following kernel call trace will be created when a GSO skb is processed by the CHECKSUM target: WARNING: CPU: 34 PID: 806048 at /build/linux-zdslHp/linux-4.4.0/net/core/dev.c:2456 skb_warn_bad_offload+0xcf/0x110() qr-f78bfdf7-fe: caps=(0x0fdb58e9, 0x0fdb58e9) len=1955 data_len=479 gso_size=1448 gso_type=1 ip_summed=3 CPU: 34 PID: 806048 Comm: haproxy Tainted: GW OE 4.4.0-138-generic #164-Ubuntu Call Trace: dump_stack+0x63/0x90 warn_slowpath_common+0x82/0xc0 warn_slowpath_fmt+0x5c/0x80 ? ___ratelimit+0xa2/0xe0 skb_warn_bad_offload+0xcf/0x110 skb_checksum_help+0x185/0x1a0 checksum_tg+0x22/0x29 [xt_CHECKSUM] ipt_do_table+0x301/0x730 [ip_tables] ? ipt_do_table+0x349/0x730 [ip_tables] iptable_mangle_hook+0x39/0x107 [iptable_mangle] nf_iterate+0x68/0x80 nf_hook_slow+0x73/0xd0 ip_output+0xcf/0xe0 ? __ip_flush_pending_frames.isra.43+0x90/0x90 ip_local_out+0x3b/0x50 ip_queue_xmit+0x154/0x390 __tcp_transmit_skb+0x52b/0x9b0 tcp_write_xmit+0x1dd/0xf50 __tcp_push_pending_frames+0x31/0xd0 tcp_push+0xec/0x110 tcp_sendmsg+0x749/0xba0 inet_sendmsg+0x6b/0xa0 sock_sendmsg+0x3e/0x50 SYSC_sendto+0x101/0x190 ? __sys_sendmsg+0x51/0x90 SyS_sendto+0xe/0x10 entry_SYSCALL_64_fastpath+0x22/0xc1 The CHECKSUM target does not support GSO skbs, and when a GSO skb is passed to skb_checksum_help(), it errors out and skb_warn_bad_offload() is called. The above call trace was found in a customer environment which has an Openstack deployment, with the following sorts of iptables rules set: -A neutron-l3-agent-POSTROUTING -o qr-+ -p tcp -m tcp --sport 9697 -j CHECKSUM --checksum-fill -A neutron-dhcp-age-POSTROUTING -p udp -m udp --dport 68 -j CHECKSUM --checksum-fill This was causing haproxy running on the node to crash and restart every time a GSO skb was processed by the CHECKSUM target. I recommend reading the netdev mailing list thread for more details: https://www.spinics.net/lists/netdev/msg517366.html [Fix] This was fixed in 4.19 upstream with the below commit: commit 10568f6c5761db24249c610c94d6e44d5505a0ba Author: Florian Westphal Date: Wed Aug 22 11:33:27 2018 +0200 Subject: netfilter: xt_checksum: ignore gso skbs This commit adds a check to see if the current skb is a gso skb, and if it is, skips skb_checksum_help(). It then continues on to check if the packet uses udp, and if it does, exits early. Otherwise it prints a single warning that CHECKSUM should be avoided, and if really needed, only for use with outbound udp. Note, 10568f6c5761db24249c610c94d6e44d5505a0ba was included in upstream stable version 4.18.13, and was backported to bionic in 4.15.0-58.64 by LP #1836426. This patch required minor backporting for 4.4, by slightly adjusting the context in the final patch hunk. [Testcase] You can reproduce this by adding the following iptables rule to the mangle table: -t mangle -A POSTROUTING -p tcp -m tcp --sport 80 -j CHECKSUM --checksum-fill and running traffic over port 80 with incorrect checksums in the ip header. I built a test kernel, which is available here: https://launchpad.net/~mruffell/+archive/ubuntu/sf216537-test For unpatched kernels, this causes the process which was handling the socket to crash, as seen by haproxy crashing on a node in production which hits this issue. On patched kernels you see the below warning printed to dmesg and no crashes occur. xt_CHECKSUM: CHECKSUM should be avoided. If really needed, restrict with "-p udp" and only use in OUTPUT [Regression Potential] The changes are limited only to users which have CHECKSUM rules enabled in their iptables configs. Openstack commonly configures such rules on deployment, even though they are not necessary, as almost all packets have their checksum calculated by NICs these days, and CHECKSUM is only around to service old dhcp clients which would discard UDP packets with empty checksums. This commit was selected for upstream -stable 4.18.13, and has made its way into bionic 4.15.0-58.64 by LP #1836426. There have been no reported problems and those kernels would have had sufficient testing with Openstack and its configured iptables rules. If any users are affected by
