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 73A282DFF1E; Tue, 17 Jun 2025 16:15:18 +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=1750176918; cv=none; b=o34e3AAhveidPCoVzofnfa3luVfC+ZLNcwlA3VnCpWAI4cRe3y5PRRlqPdt6bkKhDRmCGuvDpdpuRIy2AsURV8A2y5QY0OHwtvT4ij2HH190etl+TCOhYykpA+V4BUi/rhsCMH/2cRIFId1GEl16uW/JxY3f7PLTbYk7pGRBjk8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1750176918; c=relaxed/simple; bh=vg96rpcWWN1P9P4ZCOvjrIgVb3koJTn4ObMl60DVrQs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=baBy/tF28eezZ1SHTvYStk88o0JVs1xh9OgBww6joV3o9OkqGXnNNwphARkS/C/aW5OKCAVA2CggJucptvKKzEHaha2D6Y77FSaal5T9soW9PvWhaFFBBu0F61J4gFM+Z3EGDO7rgdi7CtxDb+GiP1xqdyx4K6QeSd11dFkdBg0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=QO5qGH6i; 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="QO5qGH6i" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D4C54C4CEE3; Tue, 17 Jun 2025 16:15:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1750176918; bh=vg96rpcWWN1P9P4ZCOvjrIgVb3koJTn4ObMl60DVrQs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QO5qGH6iCeK2w/Xdzocy+1pDAk04el5CpuHZhT0RSqjEJFxCojwDx5e2Jsf9c2T1A 0zOTiusEfxIcftKT5NuynzXsxMQYEylr0OsJjSzoAhuKey9mGZILibJykPzweIAt/2 +Pw89UfWw6nsEorGG2bP0Zc/ySRjGplRHTfvWP9M= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Gerrard Tai , Eric Dumazet , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.6 330/356] net_sched: ets: fix a race in ets_qdisc_change() Date: Tue, 17 Jun 2025 17:27:25 +0200 Message-ID: <20250617152351.429777101@linuxfoundation.org> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250617152338.212798615@linuxfoundation.org> References: <20250617152338.212798615@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Eric Dumazet [ Upstream commit d92adacdd8c2960be856e0b82acc5b7c5395fddb ] Gerrard Tai reported a race condition in ETS, whenever SFQ perturb timer fires at the wrong time. The race is as follows: CPU 0 CPU 1 [1]: lock root [2]: qdisc_tree_flush_backlog() [3]: unlock root | | [5]: lock root | [6]: rehash | [7]: qdisc_tree_reduce_backlog() | [4]: qdisc_put() This can be abused to underflow a parent's qlen. Calling qdisc_purge_queue() instead of qdisc_tree_flush_backlog() should fix the race, because all packets will be purged from the qdisc before releasing the lock. Fixes: b05972f01e7d ("net: sched: tbf: don't call qdisc_put() while holding tree lock") Reported-by: Gerrard Tai Suggested-by: Gerrard Tai Signed-off-by: Eric Dumazet Link: https://patch.msgid.link/20250611111515.1983366-5-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/sched/sch_ets.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/sched/sch_ets.c b/net/sched/sch_ets.c index 9da86db4d2c2f..3ee46f6e005da 100644 --- a/net/sched/sch_ets.c +++ b/net/sched/sch_ets.c @@ -661,7 +661,7 @@ static int ets_qdisc_change(struct Qdisc *sch, struct nlattr *opt, for (i = q->nbands; i < oldbands; i++) { if (i >= q->nstrict && q->classes[i].qdisc->q.qlen) list_del_init(&q->classes[i].alist); - qdisc_tree_flush_backlog(q->classes[i].qdisc); + qdisc_purge_queue(q->classes[i].qdisc); } q->nstrict = nstrict; memcpy(q->prio2band, priomap, sizeof(priomap)); -- 2.39.5 ded" Error message: "Failed to find required string:'Out-Out;'." ---- end(-1) ---- 132: perf script task-analyzer tests : FAILED! ``` The buf_size if always set to phdr->p_filesz, but that may be 0 causing a free and realloc to return NULL. This is treated in filename__read_build_id like a failure and the buffer is freed again. To avoid this problem only grow buf, meaning the buf_size will never be 0. This also reduces the number of memory (re)allocations. Fixes: b691f64360ecec49 ("perf symbols: Implement poor man's ELF parser") Signed-off-by: Ian Rogers Acked-by: Namhyung Kim Cc: Adrian Hunter Cc: Alexander Shishkin Cc: Ingo Molnar Cc: Jiri Olsa Cc: Kan Liang Cc: Mark Rutland Cc: Namhyung Kim Cc: Peter Zijlstra Link: https://lore.kernel.org/r/20250501070003.22251-1-irogers@google.com Signed-off-by: Arnaldo Carvalho de Melo Signed-off-by: Sasha Levin --- tools/perf/util/symbol-minimal.c | 34 +++++++++++++++++--------------- 1 file changed, 18 insertions(+), 16 deletions(-) diff --git a/tools/perf/util/symbol-minimal.c b/tools/perf/util/symbol-minimal.c index c6f369b5d893f..d8da3da01fe6b 100644 --- a/tools/perf/util/symbol-minimal.c +++ b/tools/perf/util/symbol-minimal.c @@ -147,18 +147,19 @@ int filename__read_build_id(const char *filename, struct build_id *bid) if (phdr->p_type != PT_NOTE) continue; - buf_size = phdr->p_filesz; offset = phdr->p_offset; - tmp = realloc(buf, buf_size); - if (tmp == NULL) - goto out_free; - - buf = tmp; + if (phdr->p_filesz > buf_size) { + buf_size = phdr->p_filesz; + tmp = realloc(buf, buf_size); + if (tmp == NULL) + goto out_free; + buf = tmp; + } fseek(fp, offset, SEEK_SET); - if (fread(buf, buf_size, 1, fp) != 1) + if (fread(buf, phdr->p_filesz, 1, fp) != 1) goto out_free; - ret = read_build_id(buf, buf_size, bid, need_swap); + ret = read_build_id(buf, phdr->p_filesz, bid, need_swap); if (ret == 0) { ret = bid->size; break; @@ -199,18 +200,19 @@ int filename__read_build_id(const char *filename, struct build_id *bid) if (phdr->p_type != PT_NOTE) continue; - buf_size = phdr->p_filesz; offset = phdr->p_offset; - tmp = realloc(buf, buf_size); - if (tmp == NULL) - goto out_free; - - buf = tmp; + if (phdr->p_filesz > buf_size) { + buf_size = phdr->p_filesz; + tmp = realloc(buf, buf_size); + if (tmp == NULL) + goto out_free; + buf = tmp; + } fseek(fp, offset, SEEK_SET); - if (fread(buf, buf_size, 1, fp) != 1) + if (fread(buf, phdr->p_filesz, 1, fp) != 1) goto out_free; - ret = read_build_id(buf, buf_size, bid, need_swap); + ret = read_build_id(buf, phdr->p_filesz, bid, need_swap); if (ret == 0) { ret = bid->size; break; -- 2.39.5