From: Ivan Vecera ivecera@redhat.com
[ Upstream commit 486b9eee57ddca5c9a2d59fc41153f36002e0a00 ]
Function ice_plug_aux_dev() assigns pf->adev field too early prior aux device initialization and on other side ice_unplug_aux_dev() starts aux device deinit and at the end assigns NULL to pf->adev. This is wrong because pf->adev should always be non-NULL only when aux device is fully initialized and ready. This wrong order causes a crash when ice_send_event_to_aux() call occurs because that function depends on non-NULL value of pf->adev and does not assume that aux device is half-initialized or half-destroyed. After order correction the race window is tiny but it is still there, as Leon mentioned and manipulation with pf->adev needs to be protected by mutex.
Fix (un-)plugging functions so pf->adev field is set after aux device init and prior aux device destroy and protect pf->adev assignment by new mutex. This mutex is also held during ice_send_event_to_aux() call to ensure that aux device is valid during that call. Note that device lock used ice_send_event_to_aux() needs to be kept to avoid race with aux drv unload.
Reproducer: cycle=1 while :;do echo "#### Cycle: $cycle"
ip link set ens7f0 mtu 9000 ip link add bond0 type bond mode 1 miimon 100 ip link set bond0 up ifenslave bond0 ens7f0 ip link set bond0 mtu 9000 ethtool -L ens7f0 combined 1 ip link del bond0 ip link set ens7f0 mtu 1500 sleep 1
let cycle++ done
In short when the device is added/removed to/from bond the aux device is unplugged/plugged. When MTU of the device is changed an event is sent to aux device asynchronously. This can race with (un)plugging operation and because pf->adev is set too early (plug) or too late (unplug) the function ice_send_event_to_aux() can touch uninitialized or destroyed fields. In the case of crash below pf->adev->dev.mutex.
Crash: [ 53.372066] bond0: (slave ens7f0): making interface the new active one [ 53.378622] bond0: (slave ens7f0): Enslaving as an active interface with an u p link [ 53.386294] IPv6: ADDRCONF(NETDEV_CHANGE): bond0: link becomes ready [ 53.549104] bond0: (slave ens7f1): Enslaving as a backup interface with an up link [ 54.118906] ice 0000:ca:00.0 ens7f0: Number of in use tx queues changed inval idating tc mappings. Priority traffic classification disabled! [ 54.233374] ice 0000:ca:00.1 ens7f1: Number of in use tx queues changed inval idating tc mappings. Priority traffic classification disabled! [ 54.248204] bond0: (slave ens7f0): Releasing backup interface [ 54.253955] bond0: (slave ens7f1): making interface the new active one [ 54.274875] bond0: (slave ens7f1): Releasing backup interface [ 54.289153] bond0 (unregistering): Released all slaves [ 55.383179] MII link monitoring set to 100 ms [ 55.398696] bond0: (slave ens7f0): making interface the new active one [ 55.405241] BUG: kernel NULL pointer dereference, address: 0000000000000080 [ 55.405289] bond0: (slave ens7f0): Enslaving as an active interface with an u p link [ 55.412198] #PF: supervisor write access in kernel mode [ 55.412200] #PF: error_code(0x0002) - not-present page [ 55.412201] PGD 25d2ad067 P4D 0 [ 55.412204] Oops: 0002 [#1] PREEMPT SMP NOPTI [ 55.412207] CPU: 0 PID: 403 Comm: kworker/0:2 Kdump: loaded Tainted: G S 5.17.0-13579-g57f2d6540f03 #1 [ 55.429094] bond0: (slave ens7f1): Enslaving as a backup interface with an up link [ 55.430224] Hardware name: Dell Inc. PowerEdge R750/06V45N, BIOS 1.4.4 10/07/ 2021 [ 55.430226] Workqueue: ice ice_service_task [ice] [ 55.468169] RIP: 0010:mutex_unlock+0x10/0x20 [ 55.472439] Code: 0f b1 13 74 96 eb e0 4c 89 ee eb d8 e8 79 54 ff ff 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 65 48 8b 04 25 40 ef 01 00 31 d2 <f0> 48 0f b1 17 75 01 c3 e9 e3 fe ff ff 0f 1f 00 0f 1f 44 00 00 48 [ 55.491186] RSP: 0018:ff4454230d7d7e28 EFLAGS: 00010246 [ 55.496413] RAX: ff1a79b208b08000 RBX: ff1a79b2182e8880 RCX: 0000000000000001 [ 55.503545] RDX: 0000000000000000 RSI: ff4454230d7d7db0 RDI: 0000000000000080 [ 55.510678] RBP: ff1a79d1c7e48b68 R08: ff4454230d7d7db0 R09: 0000000000000041 [ 55.517812] R10: 00000000000000a5 R11: 00000000000006e6 R12: ff1a79d1c7e48bc0 [ 55.524945] R13: 0000000000000000 R14: ff1a79d0ffc305c0 R15: 0000000000000000 [ 55.532076] FS: 0000000000000000(0000) GS:ff1a79d0ffc00000(0000) knlGS:0000000000000000 [ 55.540163] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 55.545908] CR2: 0000000000000080 CR3: 00000003487ae003 CR4: 0000000000771ef0 [ 55.553041] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 55.560173] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 55.567305] PKRU: 55555554 [ 55.570018] Call Trace: [ 55.572474] <TASK> [ 55.574579] ice_service_task+0xaab/0xef0 [ice] [ 55.579130] process_one_work+0x1c5/0x390 [ 55.583141] ? process_one_work+0x390/0x390 [ 55.587326] worker_thread+0x30/0x360 [ 55.590994] ? process_one_work+0x390/0x390 [ 55.595180] kthread+0xe6/0x110 [ 55.598325] ? kthread_complete_and_exit+0x20/0x20 [ 55.603116] ret_from_fork+0x1f/0x30 [ 55.606698] </TASK>
Fixes: f9f5301e7e2d ("ice: Register auxiliary device to provide RDMA") Reviewed-by: Leon Romanovsky leonro@nvidia.com Signed-off-by: Ivan Vecera ivecera@redhat.com Reviewed-by: Dave Ertman david.m.ertman@intel.com Tested-by: Gurucharan gurucharanx.g@intel.com (A Contingent worker at Intel) Signed-off-by: Tony Nguyen anthony.l.nguyen@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/intel/ice/ice.h | 1 + drivers/net/ethernet/intel/ice/ice_idc.c | 25 +++++++++++++++-------- drivers/net/ethernet/intel/ice/ice_main.c | 2 ++ 3 files changed, 20 insertions(+), 8 deletions(-)
diff --git a/drivers/net/ethernet/intel/ice/ice.h b/drivers/net/ethernet/intel/ice/ice.h index df65bb494695..89bca2ed895a 100644 --- a/drivers/net/ethernet/intel/ice/ice.h +++ b/drivers/net/ethernet/intel/ice/ice.h @@ -452,6 +452,7 @@ struct ice_pf { struct mutex avail_q_mutex; /* protects access to avail_[rx|tx]qs */ struct mutex sw_mutex; /* lock for protecting VSI alloc flow */ struct mutex tc_mutex; /* lock to protect TC changes */ + struct mutex adev_mutex; /* lock to protect aux device access */ u32 msg_enable; struct ice_ptp ptp; u16 num_rdma_msix; /* Total MSIX vectors for RDMA driver */ diff --git a/drivers/net/ethernet/intel/ice/ice_idc.c b/drivers/net/ethernet/intel/ice/ice_idc.c index a2714988dd96..1dd3622991c6 100644 --- a/drivers/net/ethernet/intel/ice/ice_idc.c +++ b/drivers/net/ethernet/intel/ice/ice_idc.c @@ -37,14 +37,17 @@ void ice_send_event_to_aux(struct ice_pf *pf, struct iidc_event *event) if (WARN_ON_ONCE(!in_task())) return;
+ mutex_lock(&pf->adev_mutex); if (!pf->adev) - return; + goto finish;
device_lock(&pf->adev->dev); iadrv = ice_get_auxiliary_drv(pf); if (iadrv && iadrv->event_handler) iadrv->event_handler(pf, event); device_unlock(&pf->adev->dev); +finish: + mutex_unlock(&pf->adev_mutex); }
/** @@ -285,7 +288,6 @@ int ice_plug_aux_dev(struct ice_pf *pf) return -ENOMEM;
adev = &iadev->adev; - pf->adev = adev; iadev->pf = pf;
adev->id = pf->aux_idx; @@ -295,18 +297,20 @@ int ice_plug_aux_dev(struct ice_pf *pf)
ret = auxiliary_device_init(adev); if (ret) { - pf->adev = NULL; kfree(iadev); return ret; }
ret = auxiliary_device_add(adev); if (ret) { - pf->adev = NULL; auxiliary_device_uninit(adev); return ret; }
+ mutex_lock(&pf->adev_mutex); + pf->adev = adev; + mutex_unlock(&pf->adev_mutex); + return 0; }
@@ -315,12 +319,17 @@ int ice_plug_aux_dev(struct ice_pf *pf) */ void ice_unplug_aux_dev(struct ice_pf *pf) { - if (!pf->adev) - return; + struct auxiliary_device *adev;
- auxiliary_device_delete(pf->adev); - auxiliary_device_uninit(pf->adev); + mutex_lock(&pf->adev_mutex); + adev = pf->adev; pf->adev = NULL; + mutex_unlock(&pf->adev_mutex); + + if (adev) { + auxiliary_device_delete(adev); + auxiliary_device_uninit(adev); + } }
/** diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c index f330bd0acf9f..27b5c75ce386 100644 --- a/drivers/net/ethernet/intel/ice/ice_main.c +++ b/drivers/net/ethernet/intel/ice/ice_main.c @@ -3447,6 +3447,7 @@ u16 ice_get_avail_rxq_count(struct ice_pf *pf) static void ice_deinit_pf(struct ice_pf *pf) { ice_service_task_stop(pf); + mutex_destroy(&pf->adev_mutex); mutex_destroy(&pf->sw_mutex); mutex_destroy(&pf->tc_mutex); mutex_destroy(&pf->avail_q_mutex); @@ -3527,6 +3528,7 @@ static int ice_init_pf(struct ice_pf *pf)
mutex_init(&pf->sw_mutex); mutex_init(&pf->tc_mutex); + mutex_init(&pf->adev_mutex);
INIT_HLIST_HEAD(&pf->aq_wait_list); spin_lock_init(&pf->aq_wait_lock);