From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnaldo Carvalho de Melo Subject: [PATCH 02/14] perf tests: Fix out of bounds access on array fd when cnt is 100 Date: Mon, 19 Mar 2018 16:01:24 -0300 Message-ID: <20180319190136.7441-3-acme@kernel.org> References: <20180319190136.7441-1-acme@kernel.org> Return-path: In-Reply-To: <20180319190136.7441-1-acme@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, linux-perf-users@vger.kernel.org, Colin Ian King , Alexander Shishkin , Jiri Olsa , Namhyung Kim , Peter Zijlstra , kernel-janitors@vger.kernel.org, Arnaldo Carvalho de Melo List-Id: linux-perf-users.vger.kernel.org From: Colin Ian King Currently when cnt is 100 an array bounds overflow occurs on the assignment of fd[cnt]. Fix this by performing the bounds check on cnt before writing to fd. Detected by cppcheck: tools/perf/tests/bp_account.c:115: (warning) Either the condition 'cnt==100' is redundant or the array 'fd[100]' is accessed at index 100, which is out of bounds. Signed-off-by: Colin King Cc: Alexander Shishkin Cc: Jiri Olsa Cc: Namhyung Kim Cc: Peter Zijlstra Cc: kernel-janitors@vger.kernel.org Fixes: 032db28e5fa3 ("perf tests: Add breakpoint accounting/modify test") Link: http://lkml.kernel.org/r/20180314173354.11250-1-colin.king@canonical.com Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/tests/bp_account.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/tools/perf/tests/bp_account.c b/tools/perf/tests/bp_account.c index 2f75fa0c4fef..9e88d7608951 100644 --- a/tools/perf/tests/bp_account.c +++ b/tools/perf/tests/bp_account.c @@ -107,16 +107,14 @@ static int detect_cnt(bool is_x) int fd[100], cnt = 0, i; while (1) { - fd[cnt] = __event(is_x, addr, &attr); - - if (fd[cnt] < 0) - break; - if (cnt == 100) { pr_debug("way too many debug registers, fix the test\n"); return 0; } + fd[cnt] = __event(is_x, addr, &attr); + if (fd[cnt] < 0) + break; cnt++; } -- 2.14.3