From nobody Mon Oct 6 08:30:17 2025 Received: from mail-pg1-f171.google.com (mail-pg1-f171.google.com [209.85.215.171]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9C1DC6F06B; Wed, 23 Jul 2025 11:02:48 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.215.171 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753268570; cv=none; b=pVx1KxdHqBf0ybOGKFitMQWnbv3YwRLZNmykNmcExSQbqfo+yT/2UiSOpdF5MiYWPDbiWcObJrr9Ch2j9q+zpBS+mJavvtaV2V0xuTY5PGuS13kxPpgUspOHW3XjwGQdkuNXEnGggudOhU+qEykJ9xe3/TXqkpkuWl+GctYZ674= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753268570; c=relaxed/simple; bh=7TUTvKtalQdMgk4iybDHiIaixywXXBTmIw3de8n0g9Q=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=lzmrAX6ilvZs2xc6WfrTfemOxmk0HxXDyQgEaeArRQpvQttQ/KfD2KMyWFdT76BTDQmptfTXEsSjxEitDIVQqqtk4GuxAmgnb4uuMQpzAmJhE7AfUZhm/2rJCSqjYdU9x0OH24DZTOMLZpFCD5SHu6D2FsKCfP3dEC51fmyiHkk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kzalloc.com; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=209.85.215.171 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=kzalloc.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-pg1-f171.google.com with SMTP id 41be03b00d2f7-b3f2ea2f96fso322898a12.0; Wed, 23 Jul 2025 04:02:48 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1753268568; x=1753873368; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=eIaSs7Fhujj41mthw9JZxgIBsdS8g/yHvNODnq+JPvU=; b=cTBswxG5dBIXGNX/Jbeh/s/ruLmOn6lAvY6IkCshLatGAQ5rbgDVbnqT4p+K4sYQ/l 0ZQoSA2eMy0xEDOF5cN8PUTVOuyFs8G+b1FuO4tSjgbBOcs/n1EDKYa6IBbYhHbx4e4y mE/rWN1HH2jCQD87/cyNT0cAVYnwZIeliugk6VWBEgWWYcAr/WNqnQrjAShbgfPLjElR k+S6MCQn9L0Qa6osdKBDZWg+VRweJVLN/Dcj5v9Ml61jizF7KzoF16ZwU4iIqYyHTFGX x14cDV3yyB5tQqej/vuTkyx2zVMRVn1Y+gQF1aH88pFl5q5c23PeVu8ZtiIVfCxoaiZL ZyZw== X-Forwarded-Encrypted: i=1; AJvYcCUOd+3RwgeLJXD/RUrmzdacGacmZWM4XhOnEuP+HA06G61rYy0Pi2g+7KhrRyI/SGHeqdPPlsOGR1QPiTPdcvmlLw==@vger.kernel.org, AJvYcCUa1iDIGMK9b5jqBFB0qmHPYZSWPUabXqLhfy17AueKfhAfWLw6taVMwA5kTEeL4gNUd1xkkRZasOHDga8=@vger.kernel.org X-Gm-Message-State: AOJu0YxAxtQa4Pg/zNFG7Y0bwVB1ax7kPDWzCNQx1OGskOS6VO4FPHmF i0Vc296TylWOj0VaiMhAj4kf18KaMaLTxXAjctiZm+XHXwZ2W+hcwPcl X-Gm-Gg: ASbGncuf+WnS3DCp5p97/iuaktePmz8p4LMHoGcUoJXvYYpB5fwBF9UjOFUXQiuWVg+ H44oBwTpAzBsl+RMYKm4R7bx30wvk5qJSQASdYEnfD4LeAe2ZXVOf0OS8MwkJvzLnWecaTt9PEi AN7IIKr2ctwgDxDvrag2tPmnF1d6kFaeyX/wau7O+zOcg85/HCGQCy2AMWXkRYpvXhw6W3qCP4p ev+dRxLP1g64Rac34tJzQSKPcbViztK3RDLY24eHIdIrDwOSesq7nf1d6658hI4YYbp3MoRI7NR hNDiiYcBpVfeSZD5ripidT2r/cyOnrhviehV4pTjW+fG5JKZEb9mRxFDbog0E+i/ycBMCTg98TJ M5h4v9NGlE8bc X-Google-Smtp-Source: AGHT+IG2WnYfXBAsSOophfSvE8ZsJU3rbkH3GWiFlG4n7LRfHTdG8XzpOYxVzgOnCs7BXHCIpO4Q4A== X-Received: by 2002:a05:6a20:158f:b0:220:839d:1d61 with SMTP id adf61e73a8af0-23d49198aafmr1604510637.9.1753268567669; Wed, 23 Jul 2025 04:02:47 -0700 (PDT) Received: from localhost ([218.152.98.97]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-75eb876df3csm3572462b3a.7.2025.07.23.04.02.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 23 Jul 2025 04:02:47 -0700 (PDT) From: Yunseong Kim To: Will Deacon , Mark Rutland Cc: Hemendra Dassanayake , Austin Kim , Michelle Jin , linux-arm-kernel@lists.infradead.org, linux-perf-users@vger.kernel.org, linux-kernel@vger.kernel.org, Yunseong Kim , Yeoreum Yun , syzkaller@googlegroups.com Subject: [PATCH] perf: arm_pmuv3: Fix kernel panic on UBSAN from negative hw.idx in armv8pmu_enable/disable_event() Date: Wed, 23 Jul 2025 10:44:03 +0000 Message-ID: <20250723104359.364547-5-ysk@kzalloc.com> X-Mailer: git-send-email 2.50.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" When 'event->hw.idx' was negative in armv8pmu_enable/disable_event(). UBSAN: shift-out-of-bounds in drivers/perf/arm_pmuv3.c:716:25 shift exponent -1 is negative UBSAN: shift-out-of-bounds in drivers/perf/arm_pmuv3.c:658:13 shift exponent -1 is negative This occurred because a perf_event could reach armv8pmu event with a negative idx, typically when a valid counter could not be allocated. This issue was observed when running KVM on Radxa's Orion6 platform. The issue was previously guarded indirectly by armv8pmu_event_is_chained(), which internally warned and returned false for idx < 0. But since the commit 29227d6ea157 ("arm64: perf: Clean up enable/disable calls"), this check was removed. To prevent undefined behavior, add an explicit guard to early return from armv8pmu event if hw.idx < 0, similar to handling in other PMU drivers. (e.g. intel_pmu_disable_event() on arch/x86/events/intel/core.c) $ ./syz-execprog -executor=3D./syz-executor -repeat=3D0 -sandbox=3Dnone \ -disable=3Dbinfmt_misc,cgroups,close_fds,devlink_pci,ieee802154,net_dev,n= et_reset,nic_vf,swap,sysctl,tun,usb,vhci,wifi \ -procs=3D8 perf.syz r0 =3D perf_event_open(&(0x7f0000000240)=3D{ 0x0, 0x80, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, @perf_config_ext }, 0x0, 0x0, 0xffffffffffffffff, 0x0) perf_event_open(&(0x7f0000000280)=3D{ 0x0, 0x80, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, @perf_config_ext }, 0x0, 0x0, r0, 0x0) perf_event_open(&(0x7f0000000540)=3D{ 0x3, 0x80, 0x0, 0x0, 0x0, 0x0, 0x0, 0x4, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x4, @perf_bp=3D{0x0, 0x2}, 0x20, 0x0, 0x0, 0x0, 0x2, 0x0, 0x0, 0x0, 0x0, 0x0, 0x81 }, 0x0, 0x0, r0, 0x0) Tested-by: Yunseong Kim ------------[ cut here ]------------ UBSAN: shift-out-of-bounds in drivers/perf/arm_pmuv3.c:716:25 shift exponent -1 is negative CPU: 0 UID: 0 PID: 8405 Comm: syz.3.19 Tainted: G W 6.16.0= -rc2-g5982a539cdce #3 PREEMPT Tainted: [W]=3DWARN Hardware name: QEMU KVM Virtual Machine, BIOS 2025.02-8 05/13/2025 Call trace: show_stack+0x2c/0x3c (C) __dump_stack+0x30/0x40 dump_stack_lvl+0xd8/0x12c dump_stack+0x1c/0x28 ubsan_epilogue+0x14/0x48 __ubsan_handle_shift_out_of_bounds+0x2b0/0x34c armv8pmu_enable_event+0x3c4/0x4b0 armpmu_start+0xc4/0x118 perf_event_unthrottle_group+0x3a8/0x50c perf_adjust_freq_unthr_events+0x2f4/0x578 perf_adjust_freq_unthr_context+0x278/0x46c perf_event_task_tick+0x394/0x5b0 sched_tick+0x314/0x6cc update_process_times+0x374/0x4b0 tick_nohz_handler+0x334/0x480 __hrtimer_run_queues+0x3ec/0xb78 hrtimer_interrupt+0x2b8/0xb50 arch_timer_handler_virt+0x74/0x88 handle_percpu_devid_irq+0x174/0x308 generic_handle_domain_irq+0xe0/0x140 gic_handle_irq+0x6c/0x190 call_on_irq_stack+0x24/0x30 do_interrupt_handler+0xd4/0x138 el1_interrupt+0x34/0x54 el1h_64_irq_handler+0x18/0x24 el1h_64_irq+0x6c/0x70 generic_exec_single+0x2dc/0x304 (P) smp_call_function_single+0x308/0x530 perf_install_in_context+0x4a0/0x798 __arm64_sys_perf_event_open+0x184c/0x1d50 invoke_syscall+0x98/0x2b8 el0_svc_common+0x130/0x23c do_el0_svc+0x48/0x58 el0_svc+0x58/0x17c el0t_64_sync_handler+0x78/0x108 el0t_64_sync+0x198/0x19c ---[ end trace ]--- ------------[ cut here ]------------ UBSAN: shift-out-of-bounds in drivers/perf/arm_pmuv3.c:658:13 shift exponent -1 is negative CPU: 0 UID: 0 PID: 8006 Comm: syz.0.19 Not tainted 6.16.0-rc2-g5982a539cdce= #3 PREEMPT Hardware name: QEMU KVM Virtual Machine, BIOS 2025.02-8 05/13/2025 Call trace: show_stack+0x2c/0x3c (C) __dump_stack+0x30/0x40 dump_stack_lvl+0xd8/0x12c dump_stack+0x1c/0x28 ubsan_epilogue+0x14/0x48 __ubsan_handle_shift_out_of_bounds+0x2b0/0x34c armv8pmu_disable_event+0x228/0x2f8 armpmu_stop+0xa0/0x104 perf_event_throttle_group+0x354/0x4cc __perf_event_account_interrupt+0x26c/0x290 __perf_event_overflow+0xe8/0xd28 perf_event_overflow+0x38/0x4c armv8pmu_handle_irq+0x244/0x320 armpmu_dispatch_irq+0x6c/0x9c handle_percpu_devid_irq+0x174/0x308 generic_handle_domain_irq+0xe0/0x140 gic_handle_irq+0x6c/0x190 call_on_irq_stack+0x24/0x30 do_interrupt_handler+0xd4/0x138 el1_interrupt+0x34/0x54 el1h_64_irq_handler+0x18/0x24 el1h_64_irq+0x6c/0x70 generic_exec_single+0x2dc/0x304 (P) smp_call_function_single+0x308/0x530 perf_install_in_context+0x4a0/0x798 __arm64_sys_perf_event_open+0x184c/0x1d50 invoke_syscall+0x98/0x2b8 el0_svc_common+0x130/0x23c do_el0_svc+0x48/0x58 el0_svc+0x58/0x17c el0t_64_sync_handler+0x78/0x108 el0t_64_sync+0x198/0x19c ---[ end trace ]--- ------------[ cut here ]------------ UBSAN: shift-out-of-bounds in drivers/perf/arm_pmuv3.c:730:26 shift exponent -1 is negative CPU: 0 UID: 0 PID: 8006 Comm: syz.0.19 Not tainted 6.16.0-rc2-g5982a539cdce= #3 PREEMPT Hardware name: QEMU KVM Virtual Machine, BIOS 2025.02-8 05/13/2025 Call trace: show_stack+0x2c/0x3c (C) __dump_stack+0x30/0x40 dump_stack_lvl+0xd8/0x12c dump_stack+0x1c/0x28 ubsan_epilogue+0x14/0x48 __ubsan_handle_shift_out_of_bounds+0x2b0/0x34c armv8pmu_disable_event+0x298/0x2f8 armpmu_stop+0xa0/0x104 perf_event_throttle_group+0x354/0x4cc __perf_event_account_interrupt+0x26c/0x290 __perf_event_overflow+0xe8/0xd28 perf_event_overflow+0x38/0x4c armv8pmu_handle_irq+0x244/0x320 armpmu_dispatch_irq+0x6c/0x9c handle_percpu_devid_irq+0x174/0x308 generic_handle_domain_irq+0xe0/0x140 gic_handle_irq+0x6c/0x190 call_on_irq_stack+0x24/0x30 do_interrupt_handler+0xd4/0x138 el1_interrupt+0x34/0x54 el1h_64_irq_handler+0x18/0x24 el1h_64_irq+0x6c/0x70 generic_exec_single+0x2dc/0x304 (P) smp_call_function_single+0x308/0x530 perf_install_in_context+0x4a0/0x798 __arm64_sys_perf_event_open+0x184c/0x1d50 invoke_syscall+0x98/0x2b8 el0_svc_common+0x130/0x23c do_el0_svc+0x48/0x58 el0_svc+0x58/0x17c el0t_64_sync_handler+0x78/0x108 el0t_64_sync+0x198/0x19c ---[ end trace ]--- Fixes: 29227d6ea157 ("arm64: perf: Clean up enable/disable calls") Signed-off-by: Yunseong Kim Tested-by: Yunseong Kim Cc: Yeoreum Yun Cc: syzkaller@googlegroups.com --- drivers/perf/arm_pmuv3.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/perf/arm_pmuv3.c b/drivers/perf/arm_pmuv3.c index 3db9f4ed17e8..846d69643fd8 100644 --- a/drivers/perf/arm_pmuv3.c +++ b/drivers/perf/arm_pmuv3.c @@ -795,6 +795,9 @@ static void armv8pmu_enable_user_access(struct arm_pmu = *cpu_pmu) =20 static void armv8pmu_enable_event(struct perf_event *event) { + if (unlikely(event->hw.idx < 0)) + return; + armv8pmu_write_event_type(event); armv8pmu_enable_event_irq(event); armv8pmu_enable_event_counter(event); @@ -802,6 +805,9 @@ static void armv8pmu_enable_event(struct perf_event *ev= ent) =20 static void armv8pmu_disable_event(struct perf_event *event) { + if (unlikely(event->hw.idx < 0)) + return; + armv8pmu_disable_event_counter(event); armv8pmu_disable_event_irq(event); } --=20 2.50.0