From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-187.mta0.migadu.com (out-187.mta0.migadu.com [91.218.175.187]) (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 0AA208F6E for ; Mon, 1 Apr 2024 07:50:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.187 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711957855; cv=none; b=Xl+8IRca69VWv/607JHfWJGh/OpM/xcF2rEnYGVNYHcMr53KL4jkP1+b+Ss1veCtnV3gqTUO3fzOK0wB8U97vI/DP78gfhvSJ9sF532KmUPkHXU676dAUMbpVsTiRA3e+mRf+5m1uOpbr+vg44zY6cKHiPEitlUej6YHkpihkSM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711957855; c=relaxed/simple; bh=JigHOSBjxmUkvUOMIdPDj7ZNUA7z6jU/r3gDNG+eGvo=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=TGvDBxeuhMJe04e+hu0+tgRpDjey0opeFeneLNI0ZNzw1Q02VM4Xq1R1A9go3HYgxI8f1RAs2uzRypCBHAM0nXtkucnIV9oLJePD93EshAlAzbvPAxAbC2vPXCxNXqHRszddkY8d02iNfpmC8KOrmFOL9U/+LkUWWOiIAj+GwNg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=V0qVg081; arc=none smtp.client-ip=91.218.175.187 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="V0qVg081" X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1711957850; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=azKewMdXjrP1Vb4JbEgXcwOQdFK4Qn8EqameaBqK/gE=; b=V0qVg0810KrGabS8A1RI8LkcCQGVFTEA3nAaGWRVRYKnfTm00mNyoMJROK/LKJeUjJu4rs RvFal3heDvhFZsw4R91xU+y9lvil4pF94tJGMXUFNjp1rkWarNk8BFi6aQ3nKw6HDHx4X3 pI9J8BOJectgpCGLRksHyBB/Jb1lPnw= From: George Guo To: gregkh@linuxfoundation.org Cc: stable@vger.kernel.org, George Guo Subject: [PATCH 4.19 2/2] tracing: Remove unnecessary var destroy in onmax_destroy() Date: Mon, 1 Apr 2024 15:50:49 +0800 Message-Id: <20240401075049.2655077-3-dongtai.guo@linux.dev> In-Reply-To: <20240401075049.2655077-1-dongtai.guo@linux.dev> References: <20240401075049.2655077-1-dongtai.guo@linux.dev> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT From: George Guo commit ff9d31d0d46672e201fc9ff59c42f1eef5f00c77 upstream. The onmax_destroy() destroyed the onmax var, casusing a double-free error flagged by KASAN. This is tested via "./ftracetest test.d/trigger/inter-event/ trigger-onmatch-onmax-action-hist.tc". ================================================================== BUG: KASAN: use-after-free in destroy_hist_field+0x1c2/0x200 Read of size 8 at addr ffff88800a4ad100 by task ftracetest/4731 CPU: 0 PID: 4731 Comm: ftracetest Kdump: loaded Tainted: GE 4.19.90-89 #77 Source Version: Unknown Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0 Call Trace: dump_stack+0xcb/0x10b print_address_description.cold+0x54/0x249 kasan_report_error.cold+0x63/0xab ? destroy_hist_field+0x1c2/0x200 ? hist_trigger_elt_data_alloc+0x5a0/0x5a0 __asan_report_load8_noabort+0x8d/0xa0 ? destroy_hist_field+0x1c2/0x200 destroy_hist_field+0x1c2/0x200 onmax_destroy+0x72/0x1e0 ? hist_trigger_elt_data_alloc+0x5a0/0x5a0 destroy_hist_data+0x236/0xa40 event_hist_trigger_free+0x212/0x2f0 ? update_cond_flag+0x128/0x170 ? event_hist_trigger_func+0x2880/0x2880 hist_unregister_trigger+0x2f2/0x4f0 event_hist_trigger_func+0x168c/0x2880 ? tracing_map_cmp_u64+0xa0/0xa0 ? onmatch_create.constprop.0+0xf50/0xf50 ? __mutex_lock_slowpath+0x10/0x10 event_trigger_write+0x2f4/0x490 ? trigger_start+0x180/0x180 ? __fget_light+0x369/0x5d0 ? count_memcg_event_mm+0x104/0x2b0 ? trigger_start+0x180/0x180 __vfs_write+0x81/0x100 vfs_write+0x1e1/0x540 ksys_write+0x12a/0x290 ? __ia32_sys_read+0xb0/0xb0 ? __close_fd+0x1d3/0x280 do_syscall_64+0xe3/0x2d0 entry_SYSCALL_64_after_hwframe+0x5c/0xc1 RIP: 0033:0x7fd7f4c44e04 Code: 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b3 0f 1f 80 00 00 00 00 48 8d 05 39 34 0c 00 8b 00 85 c0 75 13 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 f3 c3 66 90 41 54 55 49 89 d4 53 48 89 f5 RSP: 002b:00007fff10370df8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000000000010f RCX: 00007fd7f4c44e04 RDX: 000000000000010f RSI: 000055fa765df650 RDI: 0000000000000001 RBP: 000055fa765df650 R08: 000000000000000a R09: 0000000000000000 R10: 000000000000000a R11: 0000000000000246 R12: 00007fd7f4d035c0 R13: 000000000000010f R14: 00007fd7f4d037c0 R15: 000000000000010f ================================================================== So remove the onmax_destroy() destroy_hist_field() call for that var. Fixes: 50450603ec9c("tracing: Add 'onmax' hist trigger action support") Signed-off-by: George Guo --- kernel/trace/trace_events_hist.c | 4 ---- 1 file changed, 4 deletions(-) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 7dcb96305e56..58b8a2575b8c 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -337,7 +337,6 @@ struct action_data { char *fn_name; unsigned int max_var_ref_idx; struct hist_field *max_var; - struct hist_field *var; } onmax; }; }; @@ -3489,7 +3488,6 @@ static void onmax_destroy(struct action_data *data) unsigned int i; destroy_hist_field(data->onmax.max_var, 0); - destroy_hist_field(data->onmax.var, 0); kfree(data->onmax.var_str); kfree(data->onmax.fn_name); @@ -3528,8 +3526,6 @@ static int onmax_create(struct hist_trigger_data *hist_data, if (!ref_field) return -ENOMEM; - data->onmax.var = ref_field; - data->fn = onmax_save; data->onmax.max_var_ref_idx = var_ref_idx; max_var = create_var(hist_data, file, "max", sizeof(u64), "u64"); -- 2.34.1