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 E91BE17AA6 for ; Wed, 9 Aug 2023 11:28:30 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6CE6BC433C8; Wed, 9 Aug 2023 11:28:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1691580510; bh=5R1n7n3ygwEQ/V8mHRM8rqFfAAtW3FasXhQKms0hvkw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=pIt1i5xzgJqWb4fKOL5XQHcqp17cb7rgngZHWFCGHLP1Y1AYZ7OFaF1UBjvrIOOa2 +wSLoTJioMuMgSgUozQeh7ZOF8lJLQ0ngnu1hQG9SQKROUGjUcfR8qlKAOFXC6i75O 3/RPu5PIUGIteKK3y8qpCQm9Ui4GaMWsrgiaN+1w= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Abaci Robot , "Steven Rostedt (VMware)" , Sasha Levin Subject: [PATCH 5.4 021/154] ftrace: Check if pages were allocated before calling free_pages() Date: Wed, 9 Aug 2023 12:40:52 +0200 Message-ID: <20230809103637.658277452@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230809103636.887175326@linuxfoundation.org> References: <20230809103636.887175326@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Steven Rostedt (VMware) [ Upstream commit 59300b36f85f254260c81d9dd09195fa49eb0f98 ] It is possible that on error pg->size can be zero when getting its order, which would return a -1 value. It is dangerous to pass in an order of -1 to free_pages(). Check if order is greater than or equal to zero before calling free_pages(). Link: https://lore.kernel.org/lkml/20210330093916.432697c7@gandalf.local.home/ Reported-by: Abaci Robot Signed-off-by: Steven Rostedt (VMware) Stable-dep-of: 26efd79c4624 ("ftrace: Fix possible warning on checking all pages used in ftrace_process_locs()") Signed-off-by: Sasha Levin --- kernel/trace/ftrace.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/kernel/trace/ftrace.c b/kernel/trace/ftrace.c index 97d615988ea35..5f5a766bf73bb 100644 --- a/kernel/trace/ftrace.c +++ b/kernel/trace/ftrace.c @@ -3079,7 +3079,8 @@ ftrace_allocate_pages(unsigned long num_to_init) pg = start_pg; while (pg) { order = get_count_order(pg->size / ENTRIES_PER_PAGE); - free_pages((unsigned long)pg->records, order); + if (order >= 0) + free_pages((unsigned long)pg->records, order); start_pg = pg->next; kfree(pg); pg = start_pg; @@ -5877,7 +5878,8 @@ void ftrace_release_mod(struct module *mod) clear_mod_from_hashes(pg); order = get_count_order(pg->size / ENTRIES_PER_PAGE); - free_pages((unsigned long)pg->records, order); + if (order >= 0) + free_pages((unsigned long)pg->records, order); tmp_page = pg->next; kfree(pg); ftrace_number_of_pages -= 1 << order; @@ -6222,7 +6224,8 @@ void ftrace_free_mem(struct module *mod, void *start_ptr, void *end_ptr) if (!pg->index) { *last_pg = pg->next; order = get_count_order(pg->size / ENTRIES_PER_PAGE); - free_pages((unsigned long)pg->records, order); + if (order >= 0) + free_pages((unsigned long)pg->records, order); ftrace_number_of_pages -= 1 << order; ftrace_number_of_groups--; kfree(pg); -- 2.39.2