[PATCH 4.9 08/65] qede: fix NULL pointer deref in __qede_remove()

From: Greg Kroah-Hartman
Date: Mon Nov 11 2019 - 13:32:37 EST


From: Manish Chopra <manishc@xxxxxxxxxxx>

[ Upstream commit deabc87111c690097c03765ea017cd500f7376fc ]

While rebooting the system with SR-IOV vfs enabled leads
to below crash due to recurrence of __qede_remove() on the VF
devices (first from .shutdown() flow of the VF itself and
another from PF's .shutdown() flow executing pci_disable_sriov())

This patch adds a safeguard in __qede_remove() flow to fix this,
so that driver doesn't attempt to remove "already removed" devices.

[ 194.360134] BUG: unable to handle kernel NULL pointer dereference at 00000000000008dc
[ 194.360227] IP: [<ffffffffc03553c4>] __qede_remove+0x24/0x130 [qede]
[ 194.360304] PGD 0
[ 194.360325] Oops: 0000 [#1] SMP
[ 194.360360] Modules linked in: tcp_lp fuse tun bridge stp llc devlink bonding ip_set nfnetlink ib_isert iscsi_target_mod ib_srpt target_core_mod ib_srp scsi_transport_srp scsi_tgt ib_ipoib ib_umad rpcrdma sunrpc rdma_ucm ib_uverbs ib_iser rdma_cm iw_cm ib_cm libiscsi scsi_transport_iscsi dell_smbios iTCO_wdt iTCO_vendor_support dell_wmi_descriptor dcdbas vfat fat pcc_cpufreq skx_edac intel_powerclamp coretemp intel_rapl iosf_mbi kvm_intel kvm irqbypass crc32_pclmul ghash_clmulni_intel aesni_intel lrw gf128mul glue_helper ablk_helper cryptd qedr ib_core pcspkr ses enclosure joydev ipmi_ssif sg i2c_i801 lpc_ich mei_me mei wmi ipmi_si ipmi_devintf ipmi_msghandler tpm_crb acpi_pad acpi_power_meter xfs libcrc32c sd_mod crc_t10dif crct10dif_generic crct10dif_pclmul crct10dif_common crc32c_intel mgag200
[ 194.361044] qede i2c_algo_bit drm_kms_helper qed syscopyarea sysfillrect nvme sysimgblt fb_sys_fops ttm nvme_core mpt3sas crc8 ptp drm pps_core ahci raid_class scsi_transport_sas libahci libata drm_panel_orientation_quirks nfit libnvdimm dm_mirror dm_region_hash dm_log dm_mod [last unloaded: ip_tables]
[ 194.361297] CPU: 51 PID: 7996 Comm: reboot Kdump: loaded Not tainted 3.10.0-1062.el7.x86_64 #1
[ 194.361359] Hardware name: Dell Inc. PowerEdge MX840c/0740HW, BIOS 2.4.6 10/15/2019
[ 194.361412] task: ffff9cea9b360000 ti: ffff9ceabebdc000 task.ti: ffff9ceabebdc000
[ 194.361463] RIP: 0010:[<ffffffffc03553c4>] [<ffffffffc03553c4>] __qede_remove+0x24/0x130 [qede]
[ 194.361534] RSP: 0018:ffff9ceabebdfac0 EFLAGS: 00010282
[ 194.361570] RAX: 0000000000000000 RBX: ffff9cd013846098 RCX: 0000000000000000
[ 194.361621] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9cd013846098
[ 194.361668] RBP: ffff9ceabebdfae8 R08: 0000000000000000 R09: 0000000000000000
[ 194.361715] R10: 00000000bfe14201 R11: ffff9ceabfe141e0 R12: 0000000000000000
[ 194.361762] R13: ffff9cd013846098 R14: 0000000000000000 R15: ffff9ceab5e48000
[ 194.361810] FS: 00007f799c02d880(0000) GS:ffff9ceacb0c0000(0000) knlGS:0000000000000000
[ 194.361865] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 194.361903] CR2: 00000000000008dc CR3: 0000001bdac76000 CR4: 00000000007607e0
[ 194.361953] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 194.362002] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 194.362051] PKRU: 55555554
[ 194.362073] Call Trace:
[ 194.362109] [<ffffffffc0355500>] qede_remove+0x10/0x20 [qede]
[ 194.362180] [<ffffffffb97d0f3e>] pci_device_remove+0x3e/0xc0
[ 194.362240] [<ffffffffb98b3c52>] __device_release_driver+0x82/0xf0
[ 194.362285] [<ffffffffb98b3ce3>] device_release_driver+0x23/0x30
[ 194.362343] [<ffffffffb97c86d4>] pci_stop_bus_device+0x84/0xa0
[ 194.362388] [<ffffffffb97c87e2>] pci_stop_and_remove_bus_device+0x12/0x20
[ 194.362450] [<ffffffffb97f153f>] pci_iov_remove_virtfn+0xaf/0x160
[ 194.362496] [<ffffffffb97f1aec>] sriov_disable+0x3c/0xf0
[ 194.362534] [<ffffffffb97f1bc3>] pci_disable_sriov+0x23/0x30
[ 194.362599] [<ffffffffc02f83c3>] qed_sriov_disable+0x5e3/0x650 [qed]
[ 194.362658] [<ffffffffb9622df6>] ? kfree+0x106/0x140
[ 194.362709] [<ffffffffc02cc0c0>] ? qed_free_stream_mem+0x70/0x90 [qed]
[ 194.362754] [<ffffffffb9622df6>] ? kfree+0x106/0x140
[ 194.362803] [<ffffffffc02cd659>] qed_slowpath_stop+0x1a9/0x1d0 [qed]
[ 194.362854] [<ffffffffc035544e>] __qede_remove+0xae/0x130 [qede]
[ 194.362904] [<ffffffffc03554e0>] qede_shutdown+0x10/0x20 [qede]
[ 194.362956] [<ffffffffb97cf90a>] pci_device_shutdown+0x3a/0x60
[ 194.363010] [<ffffffffb98b180b>] device_shutdown+0xfb/0x1f0
[ 194.363066] [<ffffffffb94b66c6>] kernel_restart_prepare+0x36/0x40
[ 194.363107] [<ffffffffb94b66e2>] kernel_restart+0x12/0x60
[ 194.363146] [<ffffffffb94b6959>] SYSC_reboot+0x229/0x260
[ 194.363196] [<ffffffffb95f200d>] ? handle_mm_fault+0x39d/0x9b0
[ 194.363253] [<ffffffffb942b621>] ? __switch_to+0x151/0x580
[ 194.363304] [<ffffffffb9b7ec28>] ? __schedule+0x448/0x9c0
[ 194.363343] [<ffffffffb94b69fe>] SyS_reboot+0xe/0x10
[ 194.363387] [<ffffffffb9b8bede>] system_call_fastpath+0x25/0x2a
[ 194.363430] Code: f9 e9 37 ff ff ff 90 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 4c 8d af 98 00 00 00 41 54 4c 89 ef 41 89 f4 53 e8 4c e4 55 f9 <80> b8 dc 08 00 00 01 48 89 c3 4c 8d b8 c0 08 00 00 4c 8b b0 c0
[ 194.363712] RIP [<ffffffffc03553c4>] __qede_remove+0x24/0x130 [qede]
[ 194.363764] RSP <ffff9ceabebdfac0>
[ 194.363791] CR2: 00000000000008dc

Signed-off-by: Manish Chopra <manishc@xxxxxxxxxxx>
Signed-off-by: Ariel Elior <aelior@xxxxxxxxxxx>
Signed-off-by: Sudarsana Kalluru <skalluru@xxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/net/ethernet/qlogic/qede/qede_main.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)

--- a/drivers/net/ethernet/qlogic/qede/qede_main.c
+++ b/drivers/net/ethernet/qlogic/qede/qede_main.c
@@ -2619,8 +2619,16 @@ enum qede_remove_mode {
static void __qede_remove(struct pci_dev *pdev, enum qede_remove_mode mode)
{
struct net_device *ndev = pci_get_drvdata(pdev);
- struct qede_dev *edev = netdev_priv(ndev);
- struct qed_dev *cdev = edev->cdev;
+ struct qede_dev *edev;
+ struct qed_dev *cdev;
+
+ if (!ndev) {
+ dev_info(&pdev->dev, "Device has already been removed\n");
+ return;
+ }
+
+ edev = netdev_priv(ndev);
+ cdev = edev->cdev;

DP_INFO(edev, "Starting qede_remove\n");