Subject: Re: [PATCH net 1/2] selftests: bonding: cause oops in bond_rr_gen_slave_id

From: Jay Vosburgh <[email-masked]>
Date: Mon, 19 Sep 2022 17:01:44 -0700

Jonathan Toppins <[email-masked]> wrote:

>This bonding selftest causes the following kernel oops on aarch64 and
>should be architectures agnostic.
>
>[  329.805838] kselftest: Running tests in drivers/net/bonding
>[  330.011028] eth0: renamed from link1_2
>[  330.220846] eth0: renamed from link1_1
>[  330.387755] bond0: (slave eth0): making interface the new active one
>[  330.394165] bond0: (slave eth0): Enslaving as an active interface with an up link
>[  330.401867] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
>[  334.586619] bond0: (slave eth0): Releasing backup interface
>[  334.671065] bond0: (slave eth0): Enslaving as an active interface with an up link
>[  334.686773] Unable to handle kernel paging request at virtual address ffff2c91ac905000
>[  334.694703] Mem abort info:
>[  334.697486]   ESR = 0x0000000096000004
>[  334.701234]   EC = 0x25: DABT (current EL), IL = 32 bits
>[  334.706536]   SET = 0, FnV = 0
>[  334.709579]   EA = 0, S1PTW = 0
>[  334.712719]   FSC = 0x04: level 0 translation fault
>[  334.717586] Data abort info:
>[  334.720454]   ISV = 0, ISS = 0x00000004
>[  334.724288]   CM = 0, WnR = 0
>[  334.727244] swapper pgtable: 4k pages, 48-bit VAs, pgdp=000008044d662000
>[  334.733944] [ffff2c91ac905000] pgd=0000000000000000, p4d=0000000000000000
>[  334.740734] Internal error: Oops: 96000004 [#1] SMP
>[  334.745602] Modules linked in: bonding tls veth rfkill sunrpc arm_spe_pmu vfat fat acpi_ipmi ipmi_ssif ixgbe igb i40e mdio ipmi_devintf ipmi_msghandler arm_cmn arm_dsu_pmu cppc_cpufreq acpi_tad fuse zram crct10dif_ce ast ghash_ce sbsa_gwdt nvme drm_vram_helper drm_ttm_helper nvme_core ttm xgene_hwmon
>[  334.772217] CPU: 7 PID: 2214 Comm: ping Not tainted 6.0.0-rc4-00133-g64ae13ed4784 #4
>[  334.779950] Hardware name: GIGABYTE R272-P31-00/MP32-AR1-00, BIOS F18v (SCP: 1.08.20211002) 12/01/2021
>[  334.789244] pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>[  334.796196] pc : bond_rr_gen_slave_id+0x40/0x124 [bonding]
>[  334.801691] lr : bond_xmit_roundrobin_slave_get+0x38/0xdc [bonding]
>[  334.807962] sp : ffff8000221733e0
>[  334.811265] x29: ffff8000221733e0 x28: ffffdbac8572d198 x27: ffff80002217357c
>[  334.818392] x26: 000000000000002a x25: ffffdbacb33ee000 x24: ffff07ff980fa000
>[  334.825519] x23: ffffdbacb2e398ba x22: ffff07ff98102000 x21: ffff07ff981029c0
>[  334.832646] x20: 0000000000000001 x19: ffff07ff981029c0 x18: 0000000000000014
>[  334.839773] x17: 0000000000000000 x16: ffffdbacb1004364 x15: 0000aaaabe2f5a62
>[  334.846899] x14: ffff07ff8e55d968 x13: ffff07ff8e55db30 x12: 0000000000000000
>[  334.854026] x11: ffffdbacb21532e8 x10: 0000000000000001 x9 : ffffdbac857178ec
>[  334.861153] x8 : ffff07ff9f6e5a28 x7 : 0000000000000000 x6 : 000000007c2b3742
>[  334.868279] x5 : ffff2c91ac905000 x4 : ffff2c91ac905000 x3 : ffff07ff9f554400
>[  334.875406] x2 : ffff2c91ac905000 x1 : 0000000000000001 x0 : ffff07ff981029c0
>[  334.882532] Call trace:
>[  334.884967]  bond_rr_gen_slave_id+0x40/0x124 [bonding]
>[  334.890109]  bond_xmit_roundrobin_slave_get+0x38/0xdc [bonding]
>[  334.896033]  __bond_start_xmit+0x128/0x3a0 [bonding]
>[  334.901001]  bond_start_xmit+0x54/0xb0 [bonding]
>[  334.905622]  dev_hard_start_xmit+0xb4/0x220
>[  334.909798]  __dev_queue_xmit+0x1a0/0x720
>[  334.913799]  arp_xmit+0x3c/0xbc
>[  334.916932]  arp_send_dst+0x98/0xd0
>[  334.920410]  arp_solicit+0xe8/0x230
>[  334.923888]  neigh_probe+0x60/0xb0
>[  334.927279]  __neigh_event_send+0x3b0/0x470
>[  334.931453]  neigh_resolve_output+0x70/0x90
>[  334.935626]  ip_finish_output2+0x158/0x514
>[  334.939714]  __ip_finish_output+0xac/0x1a4
>[  334.943800]  ip_finish_output+0x40/0xfc
>[  334.947626]  ip_output+0xf8/0x1a4
>[  334.950931]  ip_send_skb+0x5c/0x100
>[  334.954410]  ip_push_pending_frames+0x3c/0x60
>[  334.958758]  raw_sendmsg+0x458/0x6d0
>[  334.962325]  inet_sendmsg+0x50/0x80
>[  334.965805]  sock_sendmsg+0x60/0x6c
>[  334.969286]  __sys_sendto+0xc8/0x134
>[  334.972853]  __arm64_sys_sendto+0x34/0x4c
>[  334.976854]  invoke_syscall+0x78/0x100
>[  334.980594]  el0_svc_common.constprop.0+0x4c/0xf4
>[  334.985287]  do_el0_svc+0x38/0x4c
>[  334.988591]  el0_svc+0x34/0x10c
>[  334.991724]  el0t_64_sync_handler+0x11c/0x150
>[  334.996072]  el0t_64_sync+0x190/0x194
>[  334.999726] Code: b9001062 f9403c02 d53cd044 8b040042 (b8210040)
>[  335.005810] ---[ end trace 0000000000000000 ]---
>[  335.010416] Kernel panic - not syncing: Oops: Fatal exception in interrupt
>[  335.017279] SMP: stopping secondary CPUs
>[  335.021374] Kernel Offset: 0x5baca8eb0000 from 0xffff800008000000
>[  335.027456] PHYS_OFFSET: 0x80000000
>[  335.030932] CPU features: 0x0000,0085c029,19805c82
>[  335.035713] Memory Limit: none
>[  335.038756] Rebooting in 180 seconds..
>
>Signed-off-by: Jonathan Toppins <[email-masked]>
>---
> .../selftests/drivers/net/bonding/Makefile    |  3 +-
> .../bonding/bond-arp-interval-causes-panic.sh | 48 +++++++++++++++++++
> 2 files changed, 50 insertions(+), 1 deletion(-)
> create mode 100755 tools/testing/selftests/drivers/net/bonding/bond-arp-interval-causes-panic.sh
>
>diff --git a/tools/testing/selftests/drivers/net/bonding/Makefile b/tools/testing/selftests/drivers/net/bonding/Makefile
>index 0f9659407969..1d866658e541 100644
>--- a/tools/testing/selftests/drivers/net/bonding/Makefile
>+++ b/tools/testing/selftests/drivers/net/bonding/Makefile
>@@ -2,7 +2,8 @@
> # Makefile for net selftests
> 
> TEST_PROGS := bond-break-lacpdu-tx.sh \
>-	      dev_addr_lists.sh
>+	      dev_addr_lists.sh \
>+	      bond-arp-interval-causes-panic.sh
> 
> TEST_FILES := lag_lib.sh
> 
>diff --git a/tools/testing/selftests/drivers/net/bonding/bond-arp-interval-causes-panic.sh b/tools/testing/selftests/drivers/net/bonding/bond-arp-interval-causes-panic.sh
>new file mode 100755
>index 000000000000..095c262ba74c
>--- /dev/null
>+++ b/tools/testing/selftests/drivers/net/bonding/bond-arp-interval-causes-panic.sh
>@@ -0,0 +1,48 @@
>+#!/bin/sh
>+# SPDX-License-Identifier: GPL-2.0
>+#
>+# cause kernel oops in bond_rr_gen_slave_id
>+DEBUG=${DEBUG:-0}
>+
>+set -e
>+test ${DEBUG} -ne 0 && set -x
>+
>+function finish()
>+{
>+	ip -all netns delete

	Would it be friendlier to only delete the netns created by the
test itself?

	I'm not too familiar with the selftest harness, so I'm not sure
if it handles that (runs the test in a container or something), but if
the test is run directly could this clobber other netns unrelated to the
test?

	-J

>+	ip link del link1_1 || true
>+}
>+
>+trap finish EXIT
>+
>+client_ip4=192.168.1.198
>+server_ip4=192.168.1.254
>+
>+# setup kernel so it reboots after causing the panic
>+echo 180 >/proc/sys/kernel/panic
>+
>+# build namespaces
>+ip link add dev link1_1 type veth peer name link1_2
>+
>+ip netns add "server"
>+ip link set dev link1_2 netns server up name eth0
>+ip netns exec server ip addr add ${server_ip4}/24 dev eth0
>+
>+ip netns add "client"
>+ip link set dev link1_1 netns client down name eth0
>+ip netns exec client ip link add dev bond0 down type bond mode 1 \
>+	miimon 100 all_slaves_active 1
>+ip netns exec client ip link set dev eth0 down master bond0
>+ip netns exec client ip link set dev bond0 up
>+ip netns exec client ip addr add ${client_ip4}/24 dev bond0
>+ip netns exec client ping -c 5 $server_ip4 >/dev/null
>+
>+ip netns exec client ip link set dev eth0 down nomaster
>+ip netns exec client ip link set dev bond0 down
>+ip netns exec client ip link set dev bond0 type bond mode 0 \
>+	arp_interval 1000 arp_ip_target "+${server_ip4}"
>+ip netns exec client ip link set dev eth0 down master bond0
>+ip netns exec client ip link set dev bond0 up
>+ip netns exec client ping -c 5 $server_ip4 >/dev/null
>+
>+exit 0
>-- 
>2.31.1
>

---
	-Jay Vosburgh, [email-masked]