From: Martin KaFai Lau martin.lau@kernel.org

[ Upstream commit ee9fd0ac3017c4313be91a220a9ac4c99dde7ad4 ]

KCSAN reported a data-race when accessing node->ref. Although node->ref does not have to be accurate, take this chance to use a more common READ_ONCE() and WRITE_ONCE() pattern instead of data_race().

There is an existing bpf_lru_node_is_ref() and bpf_lru_node_set_ref(). This patch also adds bpf_lru_node_clear_ref() to do the WRITE_ONCE(node->ref, 0) also.

================================================================== BUG: KCSAN: data-race in __bpf_lru_list_rotate / __htab_lru_percpu_map_update_elem

write to 0xffff888137038deb of 1 bytes by task 11240 on cpu 1: __bpf_lru_node_move kernel/bpf/bpf_lru_list.c:113 [inline] __bpf_lru_list_rotate_active kernel/bpf/bpf_lru_list.c:149 [inline] __bpf_lru_list_rotate+0x1bf/0x750 kernel/bpf/bpf_lru_list.c:240 bpf_lru_list_pop_free_to_local kernel/bpf/bpf_lru_list.c:329 [inline] bpf_common_lru_pop_free kernel/bpf/bpf_lru_list.c:447 [inline] bpf_lru_pop_free+0x638/0xe20 kernel/bpf/bpf_lru_list.c:499 prealloc_lru_pop kernel/bpf/hashtab.c:290 [inline] __htab_lru_percpu_map_update_elem+0xe7/0x820 kernel/bpf/hashtab.c:1316 bpf_percpu_hash_update+0x5e/0x90 kernel/bpf/hashtab.c:2313 bpf_map_update_value+0x2a9/0x370 kernel/bpf/syscall.c:200 generic_map_update_batch+0x3ae/0x4f0 kernel/bpf/syscall.c:1687 bpf_map_do_batch+0x2d9/0x3d0 kernel/bpf/syscall.c:4534 __sys_bpf+0x338/0x810 __do_sys_bpf kernel/bpf/syscall.c:5096 [inline] __se_sys_bpf kernel/bpf/syscall.c:5094 [inline] __x64_sys_bpf+0x43/0x50 kernel/bpf/syscall.c:5094 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff888137038deb of 1 bytes by task 11241 on cpu 0: bpf_lru_node_set_ref kernel/bpf/bpf_lru_list.h:70 [inline] __htab_lru_percpu_map_update_elem+0x2f1/0x820 kernel/bpf/hashtab.c:1332 bpf_percpu_hash_update+0x5e/0x90 kernel/bpf/hashtab.c:2313 bpf_map_update_value+0x2a9/0x370 kernel/bpf/syscall.c:200 generic_map_update_batch+0x3ae/0x4f0 kernel/bpf/syscall.c:1687 bpf_map_do_batch+0x2d9/0x3d0 kernel/bpf/syscall.c:4534 __sys_bpf+0x338/0x810 __do_sys_bpf kernel/bpf/syscall.c:5096 [inline] __se_sys_bpf kernel/bpf/syscall.c:5094 [inline] __x64_sys_bpf+0x43/0x50 kernel/bpf/syscall.c:5094 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x01 -> 0x00

Reported by Kernel Concurrency Sanitizer on: CPU: 0 PID: 11241 Comm: syz-executor.3 Not tainted 6.3.0-rc7-syzkaller-00136-g6a66fdd29ea1 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023 ==================================================================

Reported-by: syzbot+ebe648a84e8784763f82@syzkaller.appspotmail.com Signed-off-by: Martin KaFai Lau martin.lau@kernel.org Acked-by: Yonghong Song yhs@fb.com Link: https://lore.kernel.org/r/20230511043748.1384166-1-martin.lau@linux.dev Signed-off-by: Alexei Starovoitov ast@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- kernel/bpf/bpf_lru_list.c | 21 +++++++++++++-------- kernel/bpf/bpf_lru_list.h | 7 ++----- 2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/kernel/bpf/bpf_lru_list.c b/kernel/bpf/bpf_lru_list.c index 9b5eeff72fd37..39a0e768adc39 100644 --- a/kernel/bpf/bpf_lru_list.c +++ b/kernel/bpf/bpf_lru_list.c @@ -44,7 +44,12 @@ static struct list_head *local_pending_list(struct bpf_lru_locallist *loc_l) /* bpf_lru_node helpers */ static bool bpf_lru_node_is_ref(const struct bpf_lru_node *node) { - return node->ref; + return READ_ONCE(node->ref); +} + +static void bpf_lru_node_clear_ref(struct bpf_lru_node *node) +{ + WRITE_ONCE(node->ref, 0); }

static void bpf_lru_list_count_inc(struct bpf_lru_list *l, @@ -92,7 +97,7 @@ static void __bpf_lru_node_move_in(struct bpf_lru_list *l,

bpf_lru_list_count_inc(l, tgt_type); node->type = tgt_type; - node->ref = 0; + bpf_lru_node_clear_ref(node); list_move(&node->list, &l->lists[tgt_type]); }

@@ -113,7 +118,7 @@ static void __bpf_lru_node_move(struct bpf_lru_list *l, bpf_lru_list_count_inc(l, tgt_type); node->type = tgt_type; } - node->ref = 0; + bpf_lru_node_clear_ref(node);

/* If the moving node is the next_inactive_rotation candidate, * move the next_inactive_rotation pointer also. @@ -356,7 +361,7 @@ static void __local_list_add_pending(struct bpf_lru *lru, *(u32 *)((void *)node + lru->hash_offset) = hash; node->cpu = cpu; node->type = BPF_LRU_LOCAL_LIST_T_PENDING; - node->ref = 0; + bpf_lru_node_clear_ref(node); list_add(&node->list, local_pending_list(loc_l)); }

@@ -422,7 +427,7 @@ static struct bpf_lru_node *bpf_percpu_lru_pop_free(struct bpf_lru *lru, if (!list_empty(free_list)) { node = list_first_entry(free_list, struct bpf_lru_node, list); *(u32 *)((void *)node + lru->hash_offset) = hash; - node->ref = 0; + bpf_lru_node_clear_ref(node); __bpf_lru_node_move(l, node, BPF_LRU_LIST_T_INACTIVE); }

@@ -525,7 +530,7 @@ static void bpf_common_lru_push_free(struct bpf_lru *lru, }

node->type = BPF_LRU_LOCAL_LIST_T_FREE; - node->ref = 0; + bpf_lru_node_clear_ref(node); list_move(&node->list, local_free_list(loc_l));

raw_spin_unlock_irqrestore(&loc_l->lock, flags); @@ -571,7 +576,7 @@ static void bpf_common_lru_populate(struct bpf_lru *lru, void *buf,

node = (struct bpf_lru_node *)(buf + node_offset); node->type = BPF_LRU_LIST_T_FREE; - node->ref = 0; + bpf_lru_node_clear_ref(node); list_add(&node->list, &l->lists[BPF_LRU_LIST_T_FREE]); buf += elem_size; } @@ -597,7 +602,7 @@ static void bpf_percpu_lru_populate(struct bpf_lru *lru, void *buf, node = (struct bpf_lru_node *)(buf + node_offset); node->cpu = cpu; node->type = BPF_LRU_LIST_T_FREE; - node->ref = 0; + bpf_lru_node_clear_ref(node); list_add(&node->list, &l->lists[BPF_LRU_LIST_T_FREE]); i++; buf += elem_size; diff --git a/kernel/bpf/bpf_lru_list.h b/kernel/bpf/bpf_lru_list.h index 7d4f89b7cb841..08da78b59f0b9 100644 --- a/kernel/bpf/bpf_lru_list.h +++ b/kernel/bpf/bpf_lru_list.h @@ -66,11 +66,8 @@ struct bpf_lru {

static inline void bpf_lru_node_set_ref(struct bpf_lru_node *node) { - /* ref is an approximation on access frequency. It does not - * have to be very accurate. Hence, no protection is used. - */ - if (!node->ref) - node->ref = 1; + if (!READ_ONCE(node->ref)) + WRITE_ONCE(node->ref, 1); }

int bpf_lru_init(struct bpf_lru *lru, bool percpu, u32 hash_offset,

From: Ying Hsu yinghsu@chromium.org

[ Upstream commit 004d25060c78fc31f66da0fa439c544dda1ac9d5 ]

In a setup where a Thunderbolt hub connects to Ethernet and a display through USB Type-C, users may experience a hung task timeout when they remove the cable between the PC and the Thunderbolt hub. This is because the igb_down function is called multiple times when the Thunderbolt hub is unplugged. For example, the igb_io_error_detected triggers the first call, and the igb_remove triggers the second call. The second call to igb_down will block at napi_synchronize. Here's the call trace: __schedule+0x3b0/0xddb ? __mod_timer+0x164/0x5d3 schedule+0x44/0xa8 schedule_timeout+0xb2/0x2a4 ? run_local_timers+0x4e/0x4e msleep+0x31/0x38 igb_down+0x12c/0x22a [igb 6615058754948bfde0bf01429257eb59f13030d4] __igb_close+0x6f/0x9c [igb 6615058754948bfde0bf01429257eb59f13030d4] igb_close+0x23/0x2b [igb 6615058754948bfde0bf01429257eb59f13030d4] __dev_close_many+0x95/0xec dev_close_many+0x6e/0x103 unregister_netdevice_many+0x105/0x5b1 unregister_netdevice_queue+0xc2/0x10d unregister_netdev+0x1c/0x23 igb_remove+0xa7/0x11c [igb 6615058754948bfde0bf01429257eb59f13030d4] pci_device_remove+0x3f/0x9c device_release_driver_internal+0xfe/0x1b4 pci_stop_bus_device+0x5b/0x7f pci_stop_bus_device+0x30/0x7f pci_stop_bus_device+0x30/0x7f pci_stop_and_remove_bus_device+0x12/0x19 pciehp_unconfigure_device+0x76/0xe9 pciehp_disable_slot+0x6e/0x131 pciehp_handle_presence_or_link_change+0x7a/0x3f7 pciehp_ist+0xbe/0x194 irq_thread_fn+0x22/0x4d ? irq_thread+0x1fd/0x1fd irq_thread+0x17b/0x1fd ? irq_forced_thread_fn+0x5f/0x5f kthread+0x142/0x153 ? __irq_get_irqchip_state+0x46/0x46 ? kthread_associate_blkcg+0x71/0x71 ret_from_fork+0x1f/0x30

In this case, igb_io_error_detected detaches the network interface and requests a PCIE slot reset, however, the PCIE reset callback is not being invoked and thus the Ethernet connection breaks down. As the PCIE error in this case is a non-fatal one, requesting a slot reset can be avoided. This patch fixes the task hung issue and preserves Ethernet connection by ignoring non-fatal PCIE errors.

Signed-off-by: Ying Hsu yinghsu@chromium.org Tested-by: Pucha Himasekhar Reddy himasekharx.reddy.pucha@intel.com (A Contingent worker at Intel) Signed-off-by: Tony Nguyen anthony.l.nguyen@intel.com Reviewed-by: Simon Horman simon.horman@corigine.com Link: https://lore.kernel.org/r/20230620174732.4145155-1-anthony.l.nguyen@intel.co... Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/intel/igb/igb_main.c | 5 +++++ 1 file changed, 5 insertions(+)

diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index ab54362c0992e..d7b531eae8195 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -8257,6 +8257,11 @@ static pci_ers_result_t igb_io_error_detected(struct pci_dev *pdev, struct net_device *netdev = pci_get_drvdata(pdev); struct igb_adapter *adapter = netdev_priv(netdev);

+ if (state == pci_channel_io_normal) { + dev_warn(&pdev->dev, "Non-correctable non-fatal error reported.\n"); + return PCI_ERS_RESULT_CAN_RECOVER; + } + netif_device_detach(netdev);

if (state == pci_channel_io_perm_failure)