- ---------------------- ----------------------------------------- 0.0 RCVD_IN_DNSWL_BLOCKED RBL: ADMINISTRATOR NOTICE: The query to DNSWL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#DnsBlocklists-dnsbl-block for more information. [142.0.200.124 listed in list.dnswl.org] -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -1.0 MAILING_LIST_MULTI Multiple indicators imply a widely-seen list manager -0.0 DKIMWL_WL_HIGH DKIMwl.org - High trust sender SpamTally: Final spam score: -11 When a damos_commit_quota_goals() is called for adding new DAMOS quota goals of DAMOS_QUOTA_USER_INPUT metric, current_value fields of the new goals should be also set as requested. However, damos_commit_quota_goals() is not updating the field for the case, since it is setting only metrics and target values using damos_new_quota_goal(), and metric-optional union fields using damos_commit_quota_goal_union(). As a result, users could see the first current_value parameter that committed online with a new quota goal is ignored. Users are assumed to commit the current_value for DAMOS_QUOTA_USER_INPUT quota goals, since it is being used as a feedback. Hence the real impact would be subtle. That said, this is obviously not intended behavior. Fix the issue by using damos_commit_quota_goal() which sets all quota goal parameters, instead of damos_commit_quota_goal_union(), which sets only the union fields. Fixes: 1aef9df0ee90 ("mm/damon/core: commit damos_quota_goal->nid") Cc: # 6.16.x Signed-off-by: SeongJae Park --- mm/damon/core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/damon/core.c b/mm/damon/core.c index 93848b4c6944..e72dc49d501c 100644 --- a/mm/damon/core.c +++ b/mm/damon/core.c @@ -832,7 +832,7 @@ int damos_commit_quota_goals(struct damos_quota *dst, struct damos_quota *src) src_goal->metric, src_goal->target_value); if (!new_goal) return -ENOMEM; - damos_commit_quota_goal_union(new_goal, src_goal); + damos_commit_quota_goal(new_goal, src_goal); damos_add_quota_goal(dst, new_goal); } return 0; base-commit: ccb48f0d949e274d388e66c8f80f7d1ff234ce46 -- 2.47.3 From - Tue Oct 14 00:19:23 2025 X-Mozilla-Status: 0001 X-Mozilla-Status2: 00000000 Return-Path: Delivered-To: hi@josie.lol Received: from witcher.mxrouting.net by witcher.mxrouting.net with LMTP id UGPUCQqX7WiWuzUAYBR5ng (envelope-from ) for ; Tue, 14 Oct 2025 00:19:22 +0000 Return-path: Envelope-to: hi@josie.lol Delivery-date: Tue, 14 Oct 2025 00:19:22 +0000 Received: from sv.mirrors.kernel.org ([139.178.88.99]) by witcher.mxrouting.net with esmtps (TLS1.3) tls TLS_AES_256_GCM_SHA384 (Exim 4.98) (envelope-from ) id 1v8Sl7-0000000Gxcf-2PId for hi@josie.lol; Tue, 14 Oct 2025 00:19:22 +0000 Received: from smtp.subspace.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sv.mirrors.kernel.org (Postfix) with ESMTPS id 74C43405828 for ; Tue, 14 Oct 2025 00:19:20 +0000 (UTC) Received: from localhost.localdomain (localhost.localdomain [127.0.0.1]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 1614A34BA5B; Tue, 14 Oct 2025 00:19:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="TtmGvG9c" X-Original-To: stable@vger.kernel.org Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E4D45218821 for ; Tue, 14 Oct 2025 00:19:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760401160; cv=none; b=f/maelJ72kbF4r+jsZC7AezY7ocCaiT2Yl2G/V1oXPZ/KJRVV+vuXA/P/NaC0i1qhSb/7npjKGnz5FE2cnwK8aBR1gmHnPsI+7V0B/f4rebeiB7zHGXsxHfHUV7B1GA/K05pVfP5q0cYY9sx3XzNqIc0pGOVe9JCHSBrZ5vX5F0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760401160; c=relaxed/simple; bh=VYcG6clMhsrn46Jl8ySBMCeKbEadKWMOGFoQG8mIPWw=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=GruM4+FNXsVcER9pCXmYBHa3UrupcbtjeJZ8xJBXCLT4lc4aa/JckdrQqf9kKNttex+qadS2ta/hexhXp1crBRlGkMWy+Whh4nAA7eNUtIaRmqpzOPkif3wWttv938HeDeWuPLQScHHhwUwCF2wIZtqp8QFu1Iv991u9o8z0BgA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=TtmGvG9c; arc=none smtp.client-ip=10.30.226.201 Received: by smtp.kernel.org (Postfix) with ESMTPSA id D93BCC4CEE7; Tue, 14 Oct 2025 00:19:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1760401159; bh=VYcG6clMhsrn46Jl8ySBMCeKbEadKWMOGFoQG8mIPWw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TtmGvG9cLeaxfVM80610MZOzXY0RUQb6Dr/q1bstMFBDEGNuQP600G0k6Y1KwRo4C QYqIsXfQmLLw0EvQqIo0xqddR7BtGQ3LNDEnzJFVHx1xdF4/nNFo5camuX/mu4Pa54 j1W0e9GjpfbIsgRV7pPjQAaorAFG79hZpFbjxg18LgGR4aBlflAko1dLAuqD7pZQgW qFlXP8l2lChb5TNPmE2Rteg79GCj5OJSbQGh+ZlqF/jA7fFcGUds9yEGn7HEmUZK4e t0ixVeKPiw3i503fEEpStrqY2BecHar8rF+pnoECFGBBWLsXbPl7/kWr2rOkGeMzaL xtZvm1nJrpHyw== From: Sasha Levin To: stable@vger.kernel.org Cc: Yuan Chen , "Masami Hiramatsu (Google)" , Sasha Levin Subject: [PATCH 6.12.y] tracing: Fix race condition in kprobe initialization causing NULL pointer dereference Date: Mon, 13 Oct 2025 20:19:15 -0400 Message-ID: <20251014001915.3749537-1-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <2025101316-morse-diary-ea9a@gregkh> References: <2025101316-morse-diary-ea9a@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-DKIM: signer='kernel.org' status='pass' reason='' DKIMCheck: Server passes DKIM test, 0 Spam score X-Spam-Score: -1.2 (-) X-Spam-Report: Spam detection software, running on the system "witcher.mxrouting.net", has performed the tests listed below against this email. Information: https://mxroutedocs.com/directadmin/spamfilters/ --- Content analysis details: (-1.2 points) --- pts rule name description ---- ---------------------- ----------------------------------------- 0.0 RCVD_IN_DNSWL_BLOCKED RBL: ADMINISTRATOR NOTICE: The query to DNSWL was blocked. See http://wiki.apache.org/spamassassin/DnsBlocklists#DnsBlocklists-dnsbl-block for more information. [139.178.88.99 listed in list.dnswl.org] -0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author's domain -0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain 0.1 DKIM_SIGNED Message has a DKIM or DK signature, not necessarily valid -0.1 DKIM_VALID Message has at least one valid DKIM or DK signature -1.0 MAILING_LIST_MULTI Multiple indicators imply a widely-seen list manager -0.0 DKIMWL_WL_HIGH DKIMwl.org - High trust sender SpamTally: Final spam score: -11 From: Yuan Chen [ Upstream commit 9cf9aa7b0acfde7545c1a1d912576e9bab28dc6f ] There is a critical race condition in kprobe initialization that can lead to NULL pointer dereference and kernel crash. [1135630.084782] Unable to handle kernel paging request at virtual address 0000710a04630000 ... [1135630.260314] pstate: 404003c9 (nZcv DAIF +PAN -UAO) [1135630.269239] pc : kprobe_perf_func+0x30/0x260 [1135630.277643] lr : kprobe_dispatcher+0x44/0x60 [1135630.286041] sp : ffffaeff4977fa40 [1135630.293441] x29: ffffaeff4977fa40 x28: ffffaf015340e400 [1135630.302837] x27: 0000000000000000 x26: 0000000000000000 [1135630.312257] x25: ffffaf029ed108a8 x24: ffffaf015340e528 [1135630.321705] x23: ffffaeff4977fc50 x22: ffffaeff4977fc50 [1135630.331154] x21: 0000000000000000 x20: ffffaeff4977fc50 [1135630.340586] x19: ffffaf015340e400 x18: 0000000000000000 [1135630.349985] x17: 0000000000000000 x16: 0000000000000000 [1135630.359285] x15: 0000000000000000 x14: 0000000000000000 [1135630.368445] x13: 0000000000000000 x12: 0000000000000000 [1135630.377473] x11: 0000000000000000 x10: 0000000000000000 [1135630.386411] x9 : 0000000000000000 x8 : 0000000000000000 [1135630.395252] x7 : 0000000000000000 x6 : 0000000000000000 [1135630.403963] x5 : 0000000000000000 x4 : 0000000000000000 [1135630.412545] x3 : 0000710a04630000 x2 : 0000000000000006 [1135630.421021] x1 : ffffaeff4977fc50 x0 : 0000710a04630000 [1135630.429410] Call trace: [1135630.434828] kprobe_perf_func+0x30/0x260 [1135630.441661] kprobe_dispatcher+0x44/0x60 [1135630.448396] aggr_pre_handler+0x70/0xc8 [1135630.454959] kprobe_breakpoint_handler+0x140/0x1e0 [1135630.462435] brk_handler+0xbc/0xd8 [1135630.468437] do_debug_exception+0x84/0x138 [1135630.475074] el1_dbg+0x18/0x8c [1135630.480582] security_file_permission+0x0/0xd0 [1135630.487426] vfs_write+0x70/0x1c0 [1135630.493059] ksys_write+0x5c/0xc8 [1135630.498638] __arm64_sys_write+0x24/0x30 [1135630.504821] el0_svc_common+0x78/0x130 [1135630.510838] el0_svc_handler+0x38/0x78 [1135630.516834] el0_svc+0x8/0x1b0 kernel/trace/trace_kprobe.c: 1308 0xffff3df8995039ec : ldr x21, [x24,#120] include/linux/compiler.h: 294 0xffff3df8995039f0 : ldr x1, [x21,x0] kernel/trace/trace_kprobe.c 1308: head = this_cpu_ptr(call->perf_events); 1309: if (hlist_empty(head)) 1310: return 0; crash> struct trace_event_call -o struct trace_event_call { ... [120] struct hlist_head *perf_events; //(call->perf_event) ... } crash> struct trace_event_call ffffaf015340e528 struct trace_event_call { ... perf_events = 0xffff0ad5fa89f088, //this value is correct, but x21 = 0 ... } Race Condition Analysis: The race occurs between kprobe activation and perf_events initialization: CPU0 CPU1 ==== ==== perf_kprobe_init perf_trace_event_init tp_event->perf_events = list;(1) tp_event->class->reg (2)← KPROBE ACTIVE Debug exception triggers ... kprobe_dispatcher kprobe_perf_func (tk->tp.flags & TP_FLAG_PROFILE) head = this_cpu_ptr(call->perf_events)(3) (perf_events is still NULL) Problem: 1. CPU0 executes (1) assigning tp_event->perf_events = list 2. CPU0 executes (2) enabling kprobe functionality via class->reg() 3. CPU1 triggers and reaches kprobe_dispatcher 4. CPU1 checks TP_FLAG_PROFILE - condition passes (step 2 completed) 5. CPU1 calls kprobe_perf_func() and crashes at (3) because call->perf_events is still NULL CPU1 sees that kprobe functionality is enabled but does not see that perf_events has been assigned. Add pairing read and write memory barriers to guarantee that if CPU1 sees that kprobe functionality is enabled, it must also see that perf_events has been assigned. Link: https://lore.kernel.org/all/20251001022025.44626-1-chenyuan_fl@163.com/ Fixes: 50d780560785 ("tracing/kprobes: Add probe handler dispatcher to support perf and ftrace concurrent use") Cc: stable@vger.kernel.org Signed-off-by: Yuan Chen Signed-off-by: Masami Hiramatsu (Google) [ Adjust context ] Signed-off-by: Sasha Levin --- kernel/trace/trace_fprobe.c | 11 +++++++---- kernel/trace/trace_kprobe.c | 11 +++++++---- kernel/trace/trace_probe.h | 9 +++++++-- kernel/trace/trace_uprobe.c | 12 ++++++++---- 4 files changed, 29 insertions(+), 14 deletions(-) diff --git a/kernel/trace/trace_fprobe.c b/kernel/trace/trace_fprobe.c index af7d6e2060d9d..440dbfa6bbfd5 100644 --- a/kernel/trace/trace_fprobe.c +++ b/kernel/trace/trace_fprobe.c @@ -343,12 +343,14 @@ static int fentry_dispatcher(struct fprobe *fp, unsigned long entry_ip, void *entry_data) { struct trace_fprobe *tf = container_of(fp, struct trace_fprobe, fp); + unsigned int flags = trace_probe_load_flag(&tf->tp); int ret = 0; - if (trace_probe_test_flag(&tf->tp, TP_FLAG_TRACE)) + if (flags & TP_FLAG_TRACE) fentry_trace_func(tf, entry_ip, regs); + #ifdef CONFIG_PERF_EVENTS - if (trace_probe_test_flag(&tf->tp, TP_FLAG_PROFILE)) + if (flags & TP_FLAG_PROFILE) ret = fentry_perf_func(tf, entry_ip, regs); #endif return ret; @@ -360,11 +362,12 @@ static void fexit_dispatcher(struct fprobe *fp, unsigned long entry_ip, void *entry_data) { struct trace_fprobe *tf = container_of(fp, struct trace_fprobe, fp); + unsigned int flags = trace_probe_load_flag(&tf->tp); - if (trace_probe_test_flag(&tf->tp, TP_FLAG_TRACE)) + if (flags & TP_FLAG_TRACE) fexit_trace_func(tf, entry_ip, ret_ip, regs, entry_data); #ifdef CONFIG_PERF_EVENTS - if (trace_probe_test_flag(&tf->tp, TP_FLAG_PROFILE)) + if (flags & TP_FLAG_PROFILE) fexit_perf_func(tf, entry_ip, ret_ip, regs, entry_data); #endif } diff --git a/kernel/trace/trace_kprobe.c b/kernel/trace/trace_kprobe.c index 6b9c3f3f870f4..b273611c5026c 100644 --- a/kernel/trace/trace_kprobe.c +++ b/kernel/trace/trace_kprobe.c @@ -1799,14 +1799,15 @@ static int kprobe_register(struct trace_event_call *event, static int kprobe_dispatcher(struct kprobe *kp, struct pt_regs *regs) { struct trace_kprobe *tk = container_of(kp, struct trace_kprobe, rp.kp); + unsigned int flags = trace_probe_load_flag(&tk->tp); int ret = 0; raw_cpu_inc(*tk->nhit); - if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) + if (flags & TP_FLAG_TRACE) kprobe_trace_func(tk, regs); #ifdef CONFIG_PERF_EVENTS - if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE)) + if (flags & TP_FLAG_PROFILE) ret = kprobe_perf_func(tk, regs); #endif return ret; @@ -1818,6 +1819,7 @@ kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) { struct kretprobe *rp = get_kretprobe(ri); struct trace_kprobe *tk; + unsigned int flags; /* * There is a small chance that get_kretprobe(ri) returns NULL when @@ -1830,10 +1832,11 @@ kretprobe_dispatcher(struct kretprobe_instance *ri, struct pt_regs *regs) tk = container_of(rp, struct trace_kprobe, rp); raw_cpu_inc(*tk->nhit); - if (trace_probe_test_flag(&tk->tp, TP_FLAG_TRACE)) + flags = trace_probe_load_flag(&tk->tp); + if (flags & TP_FLAG_TRACE) kretprobe_trace_func(tk, ri, regs); #ifdef CONFIG_PERF_EVENTS - if (trace_probe_test_flag(&tk->tp, TP_FLAG_PROFILE)) + if (flags & TP_FLAG_PROFILE) kretprobe_perf_func(tk, ri, regs); #endif return 0; /* We don't tweak kernel, so just return 0 */ diff --git a/kernel/trace/trace_probe.h b/kernel/trace/trace_probe.h index 8a6797c2278d9..4f54f7935d5db 100644 --- a/kernel/trace/trace_probe.h +++ b/kernel/trace/trace_probe.h @@ -269,16 +269,21 @@ struct event_file_link { struct list_head list; }; +static inline unsigned int trace_probe_load_flag(struct trace_probe *tp) +{ + return smp_load_acquire(&tp->event->flags); +} + static inline bool trace_probe_test_flag(struct trace_probe *tp, unsigned int flag) { - return !!(tp->event->flags & flag); + return !!(trace_probe_load_flag(tp) & flag); } static inline void trace_probe_set_flag(struct trace_probe *tp, unsigned int flag) { - tp->event->flags |= flag; + smp_store_release(&tp->event->flags, tp->event->flags | flag); } static inline void trace_probe_clear_flag(struct trace_probe *tp, diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 9916677acf24e..f210e71bc1550 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -1531,6 +1531,7 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) struct trace_uprobe *tu; struct uprobe_dispatch_data udd; struct uprobe_cpu_buffer *ucb = NULL; + unsigned int flags; int ret = 0; tu = container_of(con, struct trace_uprobe, consumer); @@ -1545,11 +1546,12 @@ static int uprobe_dispatcher(struct uprobe_consumer *con, struct pt_regs *regs) if (WARN_ON_ONCE(!uprobe_cpu_buffer)) return 0; - if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) + flags = trace_probe_load_flag(&tu->tp); + if (flags & TP_FLAG_TRACE) ret |= uprobe_trace_func(tu, regs, &ucb); #ifdef CONFIG_PERF_EVENTS - if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) + if (flags & TP_FLAG_PROFILE) ret |= uprobe_perf_func(tu, regs, &ucb); #endif uprobe_buffer_put(ucb); @@ -1562,6 +1564,7 @@ static int uretprobe_dispatcher(struct uprobe_consumer *con, struct trace_uprobe *tu; struct uprobe_dispatch_data udd; struct uprobe_cpu_buffer *ucb = NULL; + unsigned int flags; tu = container_of(con, struct trace_uprobe, consumer); @@ -1573,11 +1576,12 @@ static int uretprobe_dispatcher(struct uprobe_consumer *con, if (WARN_ON_ONCE(!uprobe_cpu_buffer)) return 0; - if (trace_probe_test_flag(&tu->tp, TP_FLAG_TRACE)) + flags = trace_probe_load_flag(&tu->tp); + if (flags & TP_FLAG_TRACE) uretprobe_trace_func(tu, func, regs, &ucb); #ifdef CONFIG_PERF_EVENTS - if (trace_probe_test_flag(&tu->tp, TP_FLAG_PROFILE)) + if (flags & TP_FLAG_PROFILE) uretprobe_perf_func(tu, func, regs, &ucb); #endif uprobe_buffer_put(ucb); -- 2.51.0 From - Tue Oct 14 00:20:08 2025 X-Mozilla-Status: 0001 X-Mozilla-Status2: 00000000 Return-Path: Delivered-To: hi@josie.lol Received: from witcher.mxrouting.net by witcher.mxrouting.net with LMTP id mD14IDaX7WifLj0AYBR5ng (envelope-from ) for ; Tue, 14 Oct 2025 00:20:06 +0000 Return-path: Envelope-to: hi@josie.lol Delivery-date: Tue, 14 Oct 2025 00:20:06 +0000 Received: from sv.mirrors.kernel.org ([139.178.88.99]) by witcher.mxrouting.net with esmtps (TLS1.3) tls TLS_AES_256_GCM_SHA384 (Exim 4.98) (envelope-from ) id 1v8Slq-0000000Gz7t-0tLS for hi@josie.lol; Tue, 14 Oct 2025 00:20:06 +0000 Received: from smtp.subspace.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by sv.mirrors.kernel.org (Postfix) with ESMTPS id 74727405341 for ; 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