From mboxrd@z Thu Jan 1 00:00:00 1970 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 387103BBE7 for ; Fri, 29 Mar 2024 09:40:44 +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=1711705244; cv=none; b=leGGEmC5/+NLSHgR0gFd8mNk8KCJxAQw4HNuN1XdfhDKuaiPcgjdXS/Mu0FDe21t/6cMLMnl7lOCJgX8hLMJUAv3+dlpaHVgFJaP9NHaABYxkeq0RoGavnmQ6k6QZVNQaU25cOVVAOviUDBMGD9zTwCVRU0x+ld56N0P7VB2eGg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711705244; c=relaxed/simple; bh=6+LRhLWCDGgK3cCk8d5/FDuKeHbiMR5tH8z5glJKQmc=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=kB0tMCiOdpODd1bPrdjBleW0Xamq9+R4JCF1AiLgt8R9BnzHHrtcOzYx97yAcQdSRszMZZfl9I/K8COfsxePm14NMR9rxQ9Zenr4qAmVmrFGED9NJF3bL3pltx536esyUHsOTUeK6XSKYRgWCoe5Duww3U7FQ7mmRfUgoyy8O/M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ev6x6gSU; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ev6x6gSU" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8B6FEC433F1; Fri, 29 Mar 2024 09:40:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1711705244; bh=6+LRhLWCDGgK3cCk8d5/FDuKeHbiMR5tH8z5glJKQmc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ev6x6gSUKjKIw9puYJpswcsVdJtFqnLevi6DXWeIL4ROwJiUV/cXmWp4EGIEBn+lC +oP/eu9lvZp+GhXTjg7x/1F3uZSDJuz8pz4UHE5AaFmYVNy9bAde0RLW0Ap3kiKQIk o3E/Kqx4oMMPDIhfxQAFjm2seUoA/RrPxUj8HFqU= Date: Fri, 29 Mar 2024 10:40:28 +0100 From: Greg KH To: George Guo Cc: George Guo , stable@vger.kernel.org Subject: Re: [PATCH 2/2] tracing: Remove unnecessary var destroy in onmax_destroy() Message-ID: <2024032924-rewire-broken-5b90@gregkh> References: <20240312094233.445337-1-dongtai.guo@linux.dev> <20240312094233.445337-3-dongtai.guo@linux.dev> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240312094233.445337-3-dongtai.guo@linux.dev> On Tue, Mar 12, 2024 at 05:42:33PM +0800, George Guo wrote: > From: George Guo > > 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") > Cc: stable@vger.kernel.org > 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 > This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read: https://www.kernel.org/doc/html/latest/process/stable-kernel-rules.html for how to do this properly.