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[PATCH OLK-6.6] RDMA/mlx5: Move events notifier registration to be after device registration
by Tengda Wu 06 Jan '25

06 Jan '25

From: Patrisious Haddad <phaddad(a)nvidia.com> stable inclusion from stable-v6.6.64 commit 921fcf2971a1e8d3b904ba2c2905b96f4ec3d4ad category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBEADY CVE: CVE-2024-53224 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- [ Upstream commit ede132a5cf559f3ab35a4c28bac4f4a6c20334d8 ] Move pkey change work initialization and cleanup from device resources stage to notifier stage, since this is the stage which handles this work events. Fix a race between the device deregistration and pkey change work by moving MLX5_IB_STAGE_DEVICE_NOTIFIER to be after MLX5_IB_STAGE_IB_REG in order to ensure that the notifier is deregistered before the device during cleanup. Which ensures there are no works that are being executed after the device has already unregistered which can cause the panic below. BUG: kernel NULL pointer dereference, address: 0000000000000000 PGD 0 P4D 0 Oops: 0000 [#1] PREEMPT SMP PTI CPU: 1 PID: 630071 Comm: kworker/1:2 Kdump: loaded Tainted: G W OE --------- --- 5.14.0-162.6.1.el9_1.x86_64 #1 Hardware name: Microsoft Corporation Virtual Machine/Virtual Machine, BIOS 090008 02/27/2023 Workqueue: events pkey_change_handler [mlx5_ib] RIP: 0010:setup_qp+0x38/0x1f0 [mlx5_ib] Code: ee 41 54 45 31 e4 55 89 f5 53 48 89 fb 48 83 ec 20 8b 77 08 65 48 8b 04 25 28 00 00 00 48 89 44 24 18 48 8b 07 48 8d 4c 24 16 <4c> 8b 38 49 8b 87 80 0b 00 00 4c 89 ff 48 8b 80 08 05 00 00 8b 40 RSP: 0018:ffffbcc54068be20 EFLAGS: 00010282 RAX: 0000000000000000 RBX: ffff954054494128 RCX: ffffbcc54068be36 RDX: ffff954004934000 RSI: 0000000000000001 RDI: ffff954054494128 RBP: 0000000000000023 R08: ffff954001be2c20 R09: 0000000000000001 R10: ffff954001be2c20 R11: ffff9540260133c0 R12: 0000000000000000 R13: 0000000000000023 R14: 0000000000000000 R15: ffff9540ffcb0905 FS: 0000000000000000(0000) GS:ffff9540ffc80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000010625c001 CR4: 00000000003706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: mlx5_ib_gsi_pkey_change+0x20/0x40 [mlx5_ib] process_one_work+0x1e8/0x3c0 worker_thread+0x50/0x3b0 ? rescuer_thread+0x380/0x380 kthread+0x149/0x170 ? set_kthread_struct+0x50/0x50 ret_from_fork+0x22/0x30 Modules linked in: rdma_ucm(OE) rdma_cm(OE) iw_cm(OE) ib_ipoib(OE) ib_cm(OE) ib_umad(OE) mlx5_ib(OE) mlx5_fwctl(OE) fwctl(OE) ib_uverbs(OE) mlx5_core(OE) mlxdevm(OE) ib_core(OE) mlx_compat(OE) psample mlxfw(OE) tls knem(OE) netconsole nfsv3 nfs_acl nfs lockd grace fscache netfs qrtr rfkill sunrpc intel_rapl_msr intel_rapl_common rapl hv_balloon hv_utils i2c_piix4 pcspkr joydev fuse ext4 mbcache jbd2 sr_mod sd_mod cdrom t10_pi sg ata_generic pci_hyperv pci_hyperv_intf hyperv_drm drm_shmem_helper drm_kms_helper hv_storvsc syscopyarea hv_netvsc sysfillrect sysimgblt hid_hyperv fb_sys_fops scsi_transport_fc hyperv_keyboard drm ata_piix crct10dif_pclmul crc32_pclmul crc32c_intel libata ghash_clmulni_intel hv_vmbus serio_raw [last unloaded: ib_core] CR2: 0000000000000000 ---[ end trace f6f8be4eae12f7bc ]--- Fixes: 7722f47e71e5 ("IB/mlx5: Create GSI transmission QPs when P_Key table is changed") Signed-off-by: Patrisious Haddad <phaddad(a)nvidia.com> Reviewed-by: Michael Guralnik <michaelgur(a)nvidia.com> Link: https://patch.msgid.link/d271ceeff0c08431b3cbbbb3e2d416f09b6d1621.173149694… Signed-off-by: Leon Romanovsky <leon(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Pu Lehui <pulehui(a)huawei.com> --- drivers/infiniband/hw/mlx5/main.c | 40 +++++++++++++--------------- drivers/infiniband/hw/mlx5/mlx5_ib.h | 2 +- 2 files changed, 20 insertions(+), 22 deletions(-) diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c index bc38af6cda6e..c510484e024b 100644 --- a/drivers/infiniband/hw/mlx5/main.c +++ b/drivers/infiniband/hw/mlx5/main.c @@ -2899,7 +2899,6 @@ int mlx5_ib_dev_res_srq_init(struct mlx5_ib_dev *dev) static int mlx5_ib_dev_res_init(struct mlx5_ib_dev *dev) { struct mlx5_ib_resources *devr = &dev->devr; - int port; int ret; if (!MLX5_CAP_GEN(dev->mdev, xrc)) @@ -2915,10 +2914,6 @@ static int mlx5_ib_dev_res_init(struct mlx5_ib_dev *dev) return ret; } - for (port = 0; port < ARRAY_SIZE(devr->ports); ++port) - INIT_WORK(&devr->ports[port].pkey_change_work, - pkey_change_handler); - mutex_init(&devr->cq_lock); mutex_init(&devr->srq_lock); @@ -2928,16 +2923,6 @@ static int mlx5_ib_dev_res_init(struct mlx5_ib_dev *dev) static void mlx5_ib_dev_res_cleanup(struct mlx5_ib_dev *dev) { struct mlx5_ib_resources *devr = &dev->devr; - int port; - - /* - * Make sure no change P_Key work items are still executing. - * - * At this stage, the mlx5_ib_event should be unregistered - * and it ensures that no new works are added. - */ - for (port = 0; port < ARRAY_SIZE(devr->ports); ++port) - cancel_work_sync(&devr->ports[port].pkey_change_work); /* After s0/s1 init, they are not unset during the device lifetime. */ if (devr->s1) { @@ -4201,6 +4186,13 @@ static void mlx5_ib_stage_delay_drop_cleanup(struct mlx5_ib_dev *dev) static int mlx5_ib_stage_dev_notifier_init(struct mlx5_ib_dev *dev) { + struct mlx5_ib_resources *devr = &dev->devr; + int port; + + for (port = 0; port < ARRAY_SIZE(devr->ports); ++port) + INIT_WORK(&devr->ports[port].pkey_change_work, + pkey_change_handler); + dev->mdev_events.notifier_call = mlx5_ib_event; mlx5_notifier_register(dev->mdev, &dev->mdev_events); @@ -4211,8 +4203,14 @@ static int mlx5_ib_stage_dev_notifier_init(struct mlx5_ib_dev *dev) static void mlx5_ib_stage_dev_notifier_cleanup(struct mlx5_ib_dev *dev) { + struct mlx5_ib_resources *devr = &dev->devr; + int port; + mlx5r_macsec_event_unregister(dev); mlx5_notifier_unregister(dev->mdev, &dev->mdev_events); + + for (port = 0; port < ARRAY_SIZE(devr->ports); ++port) + cancel_work_sync(&devr->ports[port].pkey_change_work); } void __mlx5_ib_remove(struct mlx5_ib_dev *dev, @@ -4286,9 +4284,6 @@ static const struct mlx5_ib_profile pf_profile = { STAGE_CREATE(MLX5_IB_STAGE_DEVICE_RESOURCES, mlx5_ib_dev_res_init, mlx5_ib_dev_res_cleanup), - STAGE_CREATE(MLX5_IB_STAGE_DEVICE_NOTIFIER, - mlx5_ib_stage_dev_notifier_init, - mlx5_ib_stage_dev_notifier_cleanup), STAGE_CREATE(MLX5_IB_STAGE_ODP, mlx5_ib_odp_init_one, mlx5_ib_odp_cleanup_one), @@ -4313,6 +4308,9 @@ static const struct mlx5_ib_profile pf_profile = { STAGE_CREATE(MLX5_IB_STAGE_IB_REG, mlx5_ib_stage_ib_reg_init, mlx5_ib_stage_ib_reg_cleanup), + STAGE_CREATE(MLX5_IB_STAGE_DEVICE_NOTIFIER, + mlx5_ib_stage_dev_notifier_init, + mlx5_ib_stage_dev_notifier_cleanup), STAGE_CREATE(MLX5_IB_STAGE_POST_IB_REG_UMR, mlx5_ib_stage_post_ib_reg_umr_init, NULL), @@ -4349,9 +4347,6 @@ const struct mlx5_ib_profile raw_eth_profile = { STAGE_CREATE(MLX5_IB_STAGE_DEVICE_RESOURCES, mlx5_ib_dev_res_init, mlx5_ib_dev_res_cleanup), - STAGE_CREATE(MLX5_IB_STAGE_DEVICE_NOTIFIER, - mlx5_ib_stage_dev_notifier_init, - mlx5_ib_stage_dev_notifier_cleanup), STAGE_CREATE(MLX5_IB_STAGE_COUNTERS, mlx5_ib_counters_init, mlx5_ib_counters_cleanup), @@ -4373,6 +4368,9 @@ const struct mlx5_ib_profile raw_eth_profile = { STAGE_CREATE(MLX5_IB_STAGE_IB_REG, mlx5_ib_stage_ib_reg_init, mlx5_ib_stage_ib_reg_cleanup), + STAGE_CREATE(MLX5_IB_STAGE_DEVICE_NOTIFIER, + mlx5_ib_stage_dev_notifier_init, + mlx5_ib_stage_dev_notifier_cleanup), STAGE_CREATE(MLX5_IB_STAGE_POST_IB_REG_UMR, mlx5_ib_stage_post_ib_reg_umr_init, NULL), diff --git a/drivers/infiniband/hw/mlx5/mlx5_ib.h b/drivers/infiniband/hw/mlx5/mlx5_ib.h index 1c83d132197f..94678e5c59dd 100644 --- a/drivers/infiniband/hw/mlx5/mlx5_ib.h +++ b/drivers/infiniband/hw/mlx5/mlx5_ib.h @@ -954,7 +954,6 @@ enum mlx5_ib_stages { MLX5_IB_STAGE_QP, MLX5_IB_STAGE_SRQ, MLX5_IB_STAGE_DEVICE_RESOURCES, - MLX5_IB_STAGE_DEVICE_NOTIFIER, MLX5_IB_STAGE_ODP, MLX5_IB_STAGE_COUNTERS, MLX5_IB_STAGE_CONG_DEBUGFS, @@ -963,6 +962,7 @@ enum mlx5_ib_stages { MLX5_IB_STAGE_PRE_IB_REG_UMR, MLX5_IB_STAGE_WHITELIST_UID, MLX5_IB_STAGE_IB_REG, + MLX5_IB_STAGE_DEVICE_NOTIFIER, MLX5_IB_STAGE_POST_IB_REG_UMR, MLX5_IB_STAGE_DELAY_DROP, MLX5_IB_STAGE_RESTRACK, -- 2.34.1

2 1

[PATCH OLK-5.10] memcg: fix soft lockup in the OOM process
by Chen Ridong 06 Jan '25

06 Jan '25

maillist inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IBE42N Reference: https://lore.kernel.org/linux-kernel/8cf29751-7c71-52ff-5492-0019ca7b0e02@g… ---------------------------------------- A soft lockup issue was found in the product with about 56,000 tasks were in the OOM cgroup, it was traversing them when the soft lockup was triggered. watchdog: BUG: soft lockup - CPU#2 stuck for 23s! [VM Thread:1503066] CPU: 2 PID: 1503066 Comm: VM Thread Kdump: loaded Tainted: G Hardware name: Huawei Cloud OpenStack Nova, BIOS RIP: 0010:console_unlock+0x343/0x540 RSP: 0000:ffffb751447db9a0 EFLAGS: 00000247 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 00000000ffffffff RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000247 RBP: ffffffffafc71f90 R08: 0000000000000000 R09: 0000000000000040 R10: 0000000000000080 R11: 0000000000000000 R12: ffffffffafc74bd0 R13: ffffffffaf60a220 R14: 0000000000000247 R15: 0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2fe6ad91f0 CR3: 00000004b2076003 CR4: 0000000000360ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vprintk_emit+0x193/0x280 printk+0x52/0x6e dump_task+0x114/0x130 mem_cgroup_scan_tasks+0x76/0x100 dump_header+0x1fe/0x210 oom_kill_process+0xd1/0x100 out_of_memory+0x125/0x570 mem_cgroup_out_of_memory+0xb5/0xd0 try_charge+0x720/0x770 mem_cgroup_try_charge+0x86/0x180 mem_cgroup_try_charge_delay+0x1c/0x40 do_anonymous_page+0xb5/0x390 handle_mm_fault+0xc4/0x1f0 This is because thousands of processes are in the OOM cgroup, it takes a long time to traverse all of them. As a result, this lead to soft lockup in the OOM process. To fix this issue, call 'cond_resched' in the 'mem_cgroup_scan_tasks' function per 1000 iterations. For global OOM, call 'touch_softlockup_watchdog' per 1000 iterations to avoid this issue. Fixes: 9cbb78bb3143 ("mm, memcg: introduce own oom handler to iterate only over its own threads") Signed-off-by: Chen Ridong <chenridong(a)huawei.com> --- mm/memcontrol.c | 7 ++++++- mm/oom_kill.c | 8 +++++++- 2 files changed, 13 insertions(+), 2 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 3e928581ab47..f5b1322ac77e 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1202,6 +1202,7 @@ int mem_cgroup_scan_tasks(struct mem_cgroup *memcg, { struct mem_cgroup *iter; int ret = 0; + int i = 0; BUG_ON(memcg == root_mem_cgroup); @@ -1210,8 +1211,12 @@ int mem_cgroup_scan_tasks(struct mem_cgroup *memcg, struct task_struct *task; css_task_iter_start(&iter->css, CSS_TASK_ITER_PROCS, &it); - while (!ret && (task = css_task_iter_next(&it))) + while (!ret && (task = css_task_iter_next(&it))) { + /* Avoid potential softlockup warning */ + if ((++i & 1023) == 0) + cond_resched(); ret = fn(task, arg); + } css_task_iter_end(&it); if (ret) { mem_cgroup_iter_break(memcg, iter); diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 9d595265bbf5..fe5f4f20c5c8 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -43,6 +43,7 @@ #include <linux/kthread.h> #include <linux/init.h> #include <linux/mmu_notifier.h> +#include <linux/nmi.h> #include <asm/tlb.h> #include "internal.h" @@ -479,10 +480,15 @@ static void dump_tasks(struct oom_control *oc) memcg_print_bad_task(oc); } else { struct task_struct *p; + int i = 0; rcu_read_lock(); - for_each_process(p) + for_each_process(p) { + /* Avoid potential softlockup warning */ + if ((++i & 1023) == 0) + touch_softlockup_watchdog(); dump_task(p, oc); + } rcu_read_unlock(); } } -- 2.34.1

2 1

[PATCH openEuler-22.03-LTS-SP1] memcg: fix soft lockup in the OOM process
by Chen Ridong 06 Jan '25

06 Jan '25

maillist inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IBE42N Reference: https://lore.kernel.org/linux-kernel/8cf29751-7c71-52ff-5492-0019ca7b0e02@g… ---------------------------------------- A soft lockup issue was found in the product with about 56,000 tasks were in the OOM cgroup, it was traversing them when the soft lockup was triggered. watchdog: BUG: soft lockup - CPU#2 stuck for 23s! [VM Thread:1503066] CPU: 2 PID: 1503066 Comm: VM Thread Kdump: loaded Tainted: G Hardware name: Huawei Cloud OpenStack Nova, BIOS RIP: 0010:console_unlock+0x343/0x540 RSP: 0000:ffffb751447db9a0 EFLAGS: 00000247 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 00000000ffffffff RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000247 RBP: ffffffffafc71f90 R08: 0000000000000000 R09: 0000000000000040 R10: 0000000000000080 R11: 0000000000000000 R12: ffffffffafc74bd0 R13: ffffffffaf60a220 R14: 0000000000000247 R15: 0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2fe6ad91f0 CR3: 00000004b2076003 CR4: 0000000000360ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vprintk_emit+0x193/0x280 printk+0x52/0x6e dump_task+0x114/0x130 mem_cgroup_scan_tasks+0x76/0x100 dump_header+0x1fe/0x210 oom_kill_process+0xd1/0x100 out_of_memory+0x125/0x570 mem_cgroup_out_of_memory+0xb5/0xd0 try_charge+0x720/0x770 mem_cgroup_try_charge+0x86/0x180 mem_cgroup_try_charge_delay+0x1c/0x40 do_anonymous_page+0xb5/0x390 handle_mm_fault+0xc4/0x1f0 This is because thousands of processes are in the OOM cgroup, it takes a long time to traverse all of them. As a result, this lead to soft lockup in the OOM process. To fix this issue, call 'cond_resched' in the 'mem_cgroup_scan_tasks' function per 1000 iterations. For global OOM, call 'touch_softlockup_watchdog' per 1000 iterations to avoid this issue. Fixes: 9cbb78bb3143 ("mm, memcg: introduce own oom handler to iterate only over its own threads") Signed-off-by: Chen Ridong <chenridong(a)huawei.com> --- mm/memcontrol.c | 7 ++++++- mm/oom_kill.c | 8 +++++++- 2 files changed, 13 insertions(+), 2 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 3e928581ab47..f5b1322ac77e 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1202,6 +1202,7 @@ int mem_cgroup_scan_tasks(struct mem_cgroup *memcg, { struct mem_cgroup *iter; int ret = 0; + int i = 0; BUG_ON(memcg == root_mem_cgroup); @@ -1210,8 +1211,12 @@ int mem_cgroup_scan_tasks(struct mem_cgroup *memcg, struct task_struct *task; css_task_iter_start(&iter->css, CSS_TASK_ITER_PROCS, &it); - while (!ret && (task = css_task_iter_next(&it))) + while (!ret && (task = css_task_iter_next(&it))) { + /* Avoid potential softlockup warning */ + if ((++i & 1023) == 0) + cond_resched(); ret = fn(task, arg); + } css_task_iter_end(&it); if (ret) { mem_cgroup_iter_break(memcg, iter); diff --git a/mm/oom_kill.c b/mm/oom_kill.c index 9d595265bbf5..fe5f4f20c5c8 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -43,6 +43,7 @@ #include <linux/kthread.h> #include <linux/init.h> #include <linux/mmu_notifier.h> +#include <linux/nmi.h> #include <asm/tlb.h> #include "internal.h" @@ -479,10 +480,15 @@ static void dump_tasks(struct oom_control *oc) memcg_print_bad_task(oc); } else { struct task_struct *p; + int i = 0; rcu_read_lock(); - for_each_process(p) + for_each_process(p) { + /* Avoid potential softlockup warning */ + if ((++i & 1023) == 0) + touch_softlockup_watchdog(); dump_task(p, oc); + } rcu_read_unlock(); } } -- 2.34.1

2 1

[PATCH OLK-6.6] memcg: fix soft lockup in the OOM process
by Chen Ridong 06 Jan '25

06 Jan '25

maillist inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IBE42N Reference: https://lore.kernel.org/linux-kernel/8cf29751-7c71-52ff-5492-0019ca7b0e02@g… ---------------------------------------- A soft lockup issue was found in the product with about 56,000 tasks were in the OOM cgroup, it was traversing them when the soft lockup was triggered. watchdog: BUG: soft lockup - CPU#2 stuck for 23s! [VM Thread:1503066] CPU: 2 PID: 1503066 Comm: VM Thread Kdump: loaded Tainted: G Hardware name: Huawei Cloud OpenStack Nova, BIOS RIP: 0010:console_unlock+0x343/0x540 RSP: 0000:ffffb751447db9a0 EFLAGS: 00000247 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 00000000ffffffff RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000247 RBP: ffffffffafc71f90 R08: 0000000000000000 R09: 0000000000000040 R10: 0000000000000080 R11: 0000000000000000 R12: ffffffffafc74bd0 R13: ffffffffaf60a220 R14: 0000000000000247 R15: 0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2fe6ad91f0 CR3: 00000004b2076003 CR4: 0000000000360ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vprintk_emit+0x193/0x280 printk+0x52/0x6e dump_task+0x114/0x130 mem_cgroup_scan_tasks+0x76/0x100 dump_header+0x1fe/0x210 oom_kill_process+0xd1/0x100 out_of_memory+0x125/0x570 mem_cgroup_out_of_memory+0xb5/0xd0 try_charge+0x720/0x770 mem_cgroup_try_charge+0x86/0x180 mem_cgroup_try_charge_delay+0x1c/0x40 do_anonymous_page+0xb5/0x390 handle_mm_fault+0xc4/0x1f0 This is because thousands of processes are in the OOM cgroup, it takes a long time to traverse all of them. As a result, this lead to soft lockup in the OOM process. To fix this issue, call 'cond_resched' in the 'mem_cgroup_scan_tasks' function per 1000 iterations. For global OOM, call 'touch_softlockup_watchdog' per 1000 iterations to avoid this issue. Fixes: 9cbb78bb3143 ("mm, memcg: introduce own oom handler to iterate only over its own threads") Signed-off-by: Chen Ridong <chenridong(a)huawei.com> --- mm/memcontrol.c | 7 ++++++- mm/oom_kill.c | 8 +++++++- 2 files changed, 13 insertions(+), 2 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 9bc0819629344..606a481afe2e2 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1322,6 +1322,7 @@ void mem_cgroup_scan_tasks(struct mem_cgroup *memcg, { struct mem_cgroup *iter; int ret = 0; + int i = 0; BUG_ON(mem_cgroup_is_root(memcg)); @@ -1330,8 +1331,12 @@ void mem_cgroup_scan_tasks(struct mem_cgroup *memcg, struct task_struct *task; css_task_iter_start(&iter->css, CSS_TASK_ITER_PROCS, &it); - while (!ret && (task = css_task_iter_next(&it))) + while (!ret && (task = css_task_iter_next(&it))) { + /* Avoid potential softlockup warning */ + if ((++i & 1023) == 0) + cond_resched(); ret = fn(task, arg); + } css_task_iter_end(&it); if (ret) { mem_cgroup_iter_break(memcg, iter); diff --git a/mm/oom_kill.c b/mm/oom_kill.c index dc932c5837479..f8a45a224ca2a 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -44,6 +44,7 @@ #include <linux/kthread.h> #include <linux/init.h> #include <linux/mmu_notifier.h> +#include <linux/nmi.h> #include <asm/tlb.h> #include "internal.h" @@ -482,10 +483,15 @@ static void dump_tasks(struct oom_control *oc) memcg_print_bad_task(oc); } else { struct task_struct *p; + int i = 0; rcu_read_lock(); - for_each_process(p) + for_each_process(p) { + /* Avoid potential softlockup warning */ + if ((++i & 1023) == 0) + touch_softlockup_watchdog(); dump_task(p, oc); + } rcu_read_unlock(); } } -- 2.34.1

2 1

[PATCH openEuler-1.0-LTS] memcg: fix soft lockup in the OOM process
by Chen Ridong 06 Jan '25

06 Jan '25

maillist inclusion category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/IBE42N CVE: NA Reference: https://lore.kernel.org/linux-kernel/8cf29751-7c71-52ff-5492-0019ca7b0e02@g… ---------------------------------------- A soft lockup issue was found in the product with about 56,000 tasks were in the OOM cgroup, it was traversing them when the soft lockup was triggered. watchdog: BUG: soft lockup - CPU#2 stuck for 23s! [VM Thread:1503066] CPU: 2 PID: 1503066 Comm: VM Thread Kdump: loaded Tainted: G Hardware name: Huawei Cloud OpenStack Nova, BIOS RIP: 0010:console_unlock+0x343/0x540 RSP: 0000:ffffb751447db9a0 EFLAGS: 00000247 ORIG_RAX: ffffffffffffff13 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 00000000ffffffff RDX: 0000000000000000 RSI: 0000000000000004 RDI: 0000000000000247 RBP: ffffffffafc71f90 R08: 0000000000000000 R09: 0000000000000040 R10: 0000000000000080 R11: 0000000000000000 R12: ffffffffafc74bd0 R13: ffffffffaf60a220 R14: 0000000000000247 R15: 0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2fe6ad91f0 CR3: 00000004b2076003 CR4: 0000000000360ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: vprintk_emit+0x193/0x280 printk+0x52/0x6e dump_task+0x114/0x130 mem_cgroup_scan_tasks+0x76/0x100 dump_header+0x1fe/0x210 oom_kill_process+0xd1/0x100 out_of_memory+0x125/0x570 mem_cgroup_out_of_memory+0xb5/0xd0 try_charge+0x720/0x770 mem_cgroup_try_charge+0x86/0x180 mem_cgroup_try_charge_delay+0x1c/0x40 do_anonymous_page+0xb5/0x390 handle_mm_fault+0xc4/0x1f0 This is because thousands of processes are in the OOM cgroup, it takes a long time to traverse all of them. As a result, this lead to soft lockup in the OOM process. To fix this issue, call 'cond_resched' in the 'mem_cgroup_scan_tasks' function per 1000 iterations. For global OOM, call 'touch_softlockup_watchdog' per 1000 iterations to avoid this issue. Fixes: 9cbb78bb3143 ("mm, memcg: introduce own oom handler to iterate only over its own threads") Signed-off-by: Chen Ridong <chenridong(a)huawei.com> --- mm/memcontrol.c | 7 ++++++- mm/oom_kill.c | 8 +++++++- 2 files changed, 13 insertions(+), 2 deletions(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 6d062b0022be..a35b94cacada 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -1230,6 +1230,7 @@ int mem_cgroup_scan_tasks(struct mem_cgroup *memcg, { struct mem_cgroup *iter; int ret = 0; + int i = 0; BUG_ON(memcg == root_mem_cgroup); @@ -1238,8 +1239,12 @@ int mem_cgroup_scan_tasks(struct mem_cgroup *memcg, struct task_struct *task; css_task_iter_start(&iter->css, CSS_TASK_ITER_PROCS, &it); - while (!ret && (task = css_task_iter_next(&it))) + while (!ret && (task = css_task_iter_next(&it))) { + /* Avoid potential softlockup warning */ + if ((++i & 1023) == 0) + cond_resched(); ret = fn(task, arg); + } css_task_iter_end(&it); if (ret) { mem_cgroup_iter_break(memcg, iter); diff --git a/mm/oom_kill.c b/mm/oom_kill.c index d917e1e47f7d..3ab166322986 100644 --- a/mm/oom_kill.c +++ b/mm/oom_kill.c @@ -42,6 +42,7 @@ #include <linux/init.h> #include <linux/mmu_notifier.h> #include <linux/share_pool.h> +#include <linux/nmi.h> #include <asm/tlb.h> #include "internal.h" @@ -518,10 +519,15 @@ static void dump_tasks(struct oom_control *oc) memcg_print_bad_task(oc); } else { struct task_struct *p; + int i = 0; rcu_read_lock(); - for_each_process(p) + for_each_process(p) { + /* Avoid potential softlockup warning */ + if ((++i & 1023) == 0) + touch_softlockup_watchdog(); dump_task(p, oc); + } rcu_read_unlock(); } } -- 2.34.1

2 1

[PATCH openEuler-1.0-LTS] media: s5p_cec: limit msg.len to CEC_MAX_MSG_SIZE
by Cai Xinchen 06 Jan '25

06 Jan '25

From: Hans Verkuil <hverkuil-cisco(a)xs4all.nl> stable inclusion from stable-v4.19.265 commit a2728bf9b6c65e46468c763e3dab7e04839d4e11 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBFBZR CVE: CVE-2022-49035 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- [ Upstream commit 93f65ce036863893c164ca410938e0968964b26c ] I expect that the hardware will have limited this to 16, but just in case it hasn't, check for this corner case. Signed-off-by: Hans Verkuil <hverkuil-cisco(a)xs4all.nl> Signed-off-by: Mauro Carvalho Chehab <mchehab(a)kernel.org> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Signed-off-by: Cai Xinchen <caixinchen1(a)huawei.com> --- drivers/media/platform/s5p-cec/s5p_cec.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/media/platform/s5p-cec/s5p_cec.c b/drivers/media/platform/s5p-cec/s5p_cec.c index 8837e2678bde..b8f125e45e38 100644 --- a/drivers/media/platform/s5p-cec/s5p_cec.c +++ b/drivers/media/platform/s5p-cec/s5p_cec.c @@ -116,6 +116,8 @@ static irqreturn_t s5p_cec_irq_handler(int irq, void *priv) dev_dbg(cec->dev, "Buffer overrun (worker did not process previous message)\n"); cec->rx = STATE_BUSY; cec->msg.len = status >> 24; + if (cec->msg.len > CEC_MAX_MSG_SIZE) + cec->msg.len = CEC_MAX_MSG_SIZE; cec->msg.rx_status = CEC_RX_STATUS_OK; s5p_cec_get_rx_buf(cec, cec->msg.len, cec->msg.msg); -- 2.34.1

2 1

[PATCH openEuler-22.03-LTS-SP1] f2fs: fix to do sanity check on node blkaddr in truncate_node()
by Yifan Qiao 06 Jan '25

06 Jan '25

From: Chao Yu <chao(a)kernel.org> mainline inclusion from mainline-v6.13-rc1 commit 6babe00ccd34fc65b78ef8b99754e32b4385f23d category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBEDP8 CVE: CVE-2024-56692 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?… -------------------------------- syzbot reports a f2fs bug as below: ------------[ cut here ]------------ kernel BUG at fs/f2fs/segment.c:2534! RIP: 0010:f2fs_invalidate_blocks+0x35f/0x370 fs/f2fs/segment.c:2534 Call Trace: truncate_node+0x1ae/0x8c0 fs/f2fs/node.c:909 f2fs_remove_inode_page+0x5c2/0x870 fs/f2fs/node.c:1288 f2fs_evict_inode+0x879/0x15c0 fs/f2fs/inode.c:856 evict+0x4e8/0x9b0 fs/inode.c:723 f2fs_handle_failed_inode+0x271/0x2e0 fs/f2fs/inode.c:986 f2fs_create+0x357/0x530 fs/f2fs/namei.c:394 lookup_open fs/namei.c:3595 [inline] open_last_lookups fs/namei.c:3694 [inline] path_openat+0x1c03/0x3590 fs/namei.c:3930 do_filp_open+0x235/0x490 fs/namei.c:3960 do_sys_openat2+0x13e/0x1d0 fs/open.c:1415 do_sys_open fs/open.c:1430 [inline] __do_sys_openat fs/open.c:1446 [inline] __se_sys_openat fs/open.c:1441 [inline] __x64_sys_openat+0x247/0x2a0 fs/open.c:1441 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0010:f2fs_invalidate_blocks+0x35f/0x370 fs/f2fs/segment.c:2534 The root cause is: on a fuzzed image, blkaddr in nat entry may be corrupted, then it will cause system panic when using it in f2fs_invalidate_blocks(), to avoid this, let's add sanity check on nat blkaddr in truncate_node(). Reported-by: syzbot+33379ce4ac76acf7d0c7(a)syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-f2fs-devel/0000000000009a6cd706224ca720@googl… Cc: stable(a)vger.kernel.org Signed-off-by: Chao Yu <chao(a)kernel.org> Signed-off-by: Jaegeuk Kim <jaegeuk(a)kernel.org> Signed-off-by: Yifan Qiao <qiaoyifan4(a)huawei.com> --- fs/f2fs/node.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/fs/f2fs/node.c b/fs/f2fs/node.c index c63274d4b74b..97c5e521acae 100644 --- a/fs/f2fs/node.c +++ b/fs/f2fs/node.c @@ -838,6 +838,15 @@ static int truncate_node(struct dnode_of_data *dn) if (err) return err; + if (ni.blk_addr != NEW_ADDR && + !f2fs_is_valid_blkaddr(sbi, ni.blk_addr, DATA_GENERIC_ENHANCE)) { + f2fs_err(sbi, + "nat entry is corrupted, run fsck to fix it, ino:%u, " + "nid:%u, blkaddr:%u", ni.ino, ni.nid, ni.blk_addr); + set_sbi_flag(sbi, SBI_NEED_FSCK); + return -EFSCORRUPTED; + } + /* Deallocate node address */ f2fs_invalidate_blocks(sbi, ni.blk_addr); dec_valid_node_count(sbi, dn->inode, dn->nid == dn->inode->i_ino); -- 2.39.2

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[PATCH OLK-6.6] KVM: arm64: Don't retire aborted MMIO instruction
by Zhang Kunbo 06 Jan '25

06 Jan '25

From: Oliver Upton <oliver.upton(a)linux.dev> from stable-v6.6.66 commit ea6b5d98fea4ee8cb443ea98fda520909e90d30e category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBEAG3 CVE: CVE-2024-53196 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- [ Upstream commit e735a5da64420a86be370b216c269b5dd8e830e2 ] Returning an abort to the guest for an unsupported MMIO access is a documented feature of the KVM UAPI. Nevertheless, it's clear that this plumbing has seen limited testing, since userspace can trivially cause a WARN in the MMIO return: WARNING: CPU: 0 PID: 30558 at arch/arm64/include/asm/kvm_emulate.h:536 kvm_handle_mmio_return+0x46c/0x5c4 arch/arm64/include/asm/kvm_emulate.h:536 Call trace: kvm_handle_mmio_return+0x46c/0x5c4 arch/arm64/include/asm/kvm_emulate.h:536 kvm_arch_vcpu_ioctl_run+0x98/0x15b4 arch/arm64/kvm/arm.c:1133 kvm_vcpu_ioctl+0x75c/0xa78 virt/kvm/kvm_main.c:4487 __do_sys_ioctl fs/ioctl.c:51 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:893 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x1e0/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x38/0x68 arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x90/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 The splat is complaining that KVM is advancing PC while an exception is pending, i.e. that KVM is retiring the MMIO instruction despite a pending synchronous external abort. Womp womp. Fix the glaring UAPI bug by skipping over all the MMIO emulation in case there is a pending synchronous exception. Note that while userspace is capable of pending an asynchronous exception (SError, IRQ, or FIQ), it is still safe to retire the MMIO instruction in this case as (1) they are by definition asynchronous, and (2) KVM relies on hardware support for pending/delivering these exceptions instead of the software state machine for advancing PC. Cc: stable(a)vger.kernel.org Fixes: da345174ceca ("KVM: arm/arm64: Allow user injection of external data aborts") Reported-by: Alexander Potapenko <glider(a)google.com> Reviewed-by: Marc Zyngier <maz(a)kernel.org> Link: https://lore.kernel.org/r/20241025203106.3529261-2-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton(a)linux.dev> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Conflicts: arch/arm64/kvm/mmio.c [ different return polarity introduced by this commit not merged: cc81b6dfc3bc8 ("KVM: arm64: Change kvm_handle_mmio_return() return polarity") ] Signed-off-by: Zhang Kunbo <zhangkunbo(a)huawei.com> --- arch/arm64/kvm/mmio.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/mmio.c b/arch/arm64/kvm/mmio.c index 40d6d056e261..bf5de05cb7a8 100644 --- a/arch/arm64/kvm/mmio.c +++ b/arch/arm64/kvm/mmio.c @@ -73,6 +73,31 @@ unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len) return data; } +static bool kvm_pending_sync_exception(struct kvm_vcpu *vcpu) +{ + if (!vcpu_get_flag(vcpu, PENDING_EXCEPTION)) + return false; + + if (vcpu_el1_is_32bit(vcpu)) { + switch (vcpu_get_flag(vcpu, EXCEPT_MASK)) { + case unpack_vcpu_flag(EXCEPT_AA32_UND): + case unpack_vcpu_flag(EXCEPT_AA32_IABT): + case unpack_vcpu_flag(EXCEPT_AA32_DABT): + return true; + default: + return false; + } + } else { + switch (vcpu_get_flag(vcpu, EXCEPT_MASK)) { + case unpack_vcpu_flag(EXCEPT_AA64_EL1_SYNC): + case unpack_vcpu_flag(EXCEPT_AA64_EL2_SYNC): + return true; + default: + return false; + } + } +} + /** * kvm_handle_mmio_return -- Handle MMIO loads after user space emulation * or in-kernel IO emulation @@ -85,8 +110,11 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu) unsigned int len; int mask; - /* Detect an already handled MMIO return */ - if (unlikely(!vcpu->mmio_needed)) + /* + * Detect if the MMIO return was already handled or if userspace aborted + * the MMIO access. + */ + if (unlikely(!vcpu->mmio_needed || kvm_pending_sync_exception(vcpu))) return 0; vcpu->mmio_needed = 0; -- 2.34.1

2 1

[PATCH OLK-5.10] KVM: arm64: Don't retire aborted MMIO instruction
by Zhang Kunbo 06 Jan '25

06 Jan '25

From: Oliver Upton <oliver.upton(a)linux.dev> stable inclusion from stable-v6.6.66 commit ea6b5d98fea4ee8cb443ea98fda520909e90d30e category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBEAG3 CVE: CVE-2024-53196 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- [ Upstream commit e735a5da64420a86be370b216c269b5dd8e830e2 ] Returning an abort to the guest for an unsupported MMIO access is a documented feature of the KVM UAPI. Nevertheless, it's clear that this plumbing has seen limited testing, since userspace can trivially cause a WARN in the MMIO return: WARNING: CPU: 0 PID: 30558 at arch/arm64/include/asm/kvm_emulate.h:536 kvm_handle_mmio_return+0x46c/0x5c4 arch/arm64/include/asm/kvm_emulate.h:536 Call trace: kvm_handle_mmio_return+0x46c/0x5c4 arch/arm64/include/asm/kvm_emulate.h:536 kvm_arch_vcpu_ioctl_run+0x98/0x15b4 arch/arm64/kvm/arm.c:1133 kvm_vcpu_ioctl+0x75c/0xa78 virt/kvm/kvm_main.c:4487 __do_sys_ioctl fs/ioctl.c:51 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:893 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x1e0/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x38/0x68 arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x90/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 The splat is complaining that KVM is advancing PC while an exception is pending, i.e. that KVM is retiring the MMIO instruction despite a pending synchronous external abort. Womp womp. Fix the glaring UAPI bug by skipping over all the MMIO emulation in case there is a pending synchronous exception. Note that while userspace is capable of pending an asynchronous exception (SError, IRQ, or FIQ), it is still safe to retire the MMIO instruction in this case as (1) they are by definition asynchronous, and (2) KVM relies on hardware support for pending/delivering these exceptions instead of the software state machine for advancing PC. Cc: stable(a)vger.kernel.org Fixes: da345174ceca ("KVM: arm/arm64: Allow user injection of external data aborts") Reported-by: Alexander Potapenko <glider(a)google.com> Reviewed-by: Marc Zyngier <maz(a)kernel.org> Link: https://lore.kernel.org/r/20241025203106.3529261-2-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton(a)linux.dev> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Conflicts: arch/arm64/kvm/mmio.c [ different return polarity introduced by this commit not merged: cc81b6dfc3bc8 ("KVM: arm64: Change kvm_handle_mmio_return() return polarity") ] Signed-off-by: Zhang Kunbo <zhangkunbo(a)huawei.com> --- arch/arm64/kvm/mmio.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/mmio.c b/arch/arm64/kvm/mmio.c index 6bda06ad3196..b0f4f3dfaf67 100644 --- a/arch/arm64/kvm/mmio.c +++ b/arch/arm64/kvm/mmio.c @@ -76,6 +76,31 @@ unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len) return data; } +static bool kvm_pending_sync_exception(struct kvm_vcpu *vcpu) +{ + if (!vcpu_get_flag(vcpu, PENDING_EXCEPTION)) + return false; + + if (vcpu_el1_is_32bit(vcpu)) { + switch (vcpu_get_flag(vcpu, EXCEPT_MASK)) { + case unpack_vcpu_flag(EXCEPT_AA32_UND): + case unpack_vcpu_flag(EXCEPT_AA32_IABT): + case unpack_vcpu_flag(EXCEPT_AA32_DABT): + return true; + default: + return false; + } + } else { + switch (vcpu_get_flag(vcpu, EXCEPT_MASK)) { + case unpack_vcpu_flag(EXCEPT_AA64_EL1_SYNC): + case unpack_vcpu_flag(EXCEPT_AA64_EL2_SYNC): + return true; + default: + return false; + } + } +} + /** * kvm_handle_mmio_return -- Handle MMIO loads after user space emulation * or in-kernel IO emulation @@ -88,8 +113,11 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu) unsigned int len; int mask; - /* Detect an already handled MMIO return */ - if (unlikely(!vcpu->mmio_needed)) + /* + * Detect if the MMIO return was already handled or if userspace aborted + * the MMIO access. + */ + if (unlikely(!vcpu->mmio_needed || kvm_pending_sync_exception(vcpu))) return 0; vcpu->mmio_needed = 0; -- 2.34.1

2 1

[PATCH openEuler-22.03-LTS-SP1] KVM: arm64: Don't retire aborted MMIO instruction
by Zhang Kunbo 06 Jan '25

06 Jan '25

From: Oliver Upton <oliver.upton(a)linux.dev> stable inclusion from stable-v6.6.66 commit ea6b5d98fea4ee8cb443ea98fda520909e90d30e category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBEAG3 CVE: CVE-2024-53196 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id… -------------------------------- [ Upstream commit e735a5da64420a86be370b216c269b5dd8e830e2 ] Returning an abort to the guest for an unsupported MMIO access is a documented feature of the KVM UAPI. Nevertheless, it's clear that this plumbing has seen limited testing, since userspace can trivially cause a WARN in the MMIO return: WARNING: CPU: 0 PID: 30558 at arch/arm64/include/asm/kvm_emulate.h:536 kvm_handle_mmio_return+0x46c/0x5c4 arch/arm64/include/asm/kvm_emulate.h:536 Call trace: kvm_handle_mmio_return+0x46c/0x5c4 arch/arm64/include/asm/kvm_emulate.h:536 kvm_arch_vcpu_ioctl_run+0x98/0x15b4 arch/arm64/kvm/arm.c:1133 kvm_vcpu_ioctl+0x75c/0xa78 virt/kvm/kvm_main.c:4487 __do_sys_ioctl fs/ioctl.c:51 [inline] __se_sys_ioctl fs/ioctl.c:893 [inline] __arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:893 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x1e0/0x23c arch/arm64/kernel/syscall.c:132 do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151 el0_svc+0x38/0x68 arch/arm64/kernel/entry-common.c:712 el0t_64_sync_handler+0x90/0xfc arch/arm64/kernel/entry-common.c:730 el0t_64_sync+0x190/0x194 arch/arm64/kernel/entry.S:598 The splat is complaining that KVM is advancing PC while an exception is pending, i.e. that KVM is retiring the MMIO instruction despite a pending synchronous external abort. Womp womp. Fix the glaring UAPI bug by skipping over all the MMIO emulation in case there is a pending synchronous exception. Note that while userspace is capable of pending an asynchronous exception (SError, IRQ, or FIQ), it is still safe to retire the MMIO instruction in this case as (1) they are by definition asynchronous, and (2) KVM relies on hardware support for pending/delivering these exceptions instead of the software state machine for advancing PC. Cc: stable(a)vger.kernel.org Fixes: da345174ceca ("KVM: arm/arm64: Allow user injection of external data aborts") Reported-by: Alexander Potapenko <glider(a)google.com> Reviewed-by: Marc Zyngier <maz(a)kernel.org> Link: https://lore.kernel.org/r/20241025203106.3529261-2-oliver.upton@linux.dev Signed-off-by: Oliver Upton <oliver.upton(a)linux.dev> Signed-off-by: Sasha Levin <sashal(a)kernel.org> Conflicts: arch/arm64/kvm/mmio.c [ different return polarity introduced by this commit not merged: cc81b6dfc3bc8 ("KVM: arm64: Change kvm_handle_mmio_return() return polarity") ] Signed-off-by: Zhang Kunbo <zhangkunbo(a)huawei.com> --- arch/arm64/kvm/mmio.c | 32 ++++++++++++++++++++++++++++++-- 1 file changed, 30 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kvm/mmio.c b/arch/arm64/kvm/mmio.c index 6a2826f1bf5e..3b68e2b3a933 100644 --- a/arch/arm64/kvm/mmio.c +++ b/arch/arm64/kvm/mmio.c @@ -72,6 +72,31 @@ unsigned long kvm_mmio_read_buf(const void *buf, unsigned int len) return data; } +static bool kvm_pending_sync_exception(struct kvm_vcpu *vcpu) +{ + if (!vcpu_get_flag(vcpu, PENDING_EXCEPTION)) + return false; + + if (vcpu_el1_is_32bit(vcpu)) { + switch (vcpu_get_flag(vcpu, EXCEPT_MASK)) { + case unpack_vcpu_flag(EXCEPT_AA32_UND): + case unpack_vcpu_flag(EXCEPT_AA32_IABT): + case unpack_vcpu_flag(EXCEPT_AA32_DABT): + return true; + default: + return false; + } + } else { + switch (vcpu_get_flag(vcpu, EXCEPT_MASK)) { + case unpack_vcpu_flag(EXCEPT_AA64_EL1_SYNC): + case unpack_vcpu_flag(EXCEPT_AA64_EL2_SYNC): + return true; + default: + return false; + } + } +} + /** * kvm_handle_mmio_return -- Handle MMIO loads after user space emulation * or in-kernel IO emulation @@ -84,8 +109,11 @@ int kvm_handle_mmio_return(struct kvm_vcpu *vcpu) unsigned int len; int mask; - /* Detect an already handled MMIO return */ - if (unlikely(!vcpu->mmio_needed)) + /* + * Detect if the MMIO return was already handled or if userspace aborted + * the MMIO access. + */ + if (unlikely(!vcpu->mmio_needed || kvm_pending_sync_exception(vcpu))) return 0; vcpu->mmio_needed = 0; -- 2.34.1

2 1