From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794366825; b=MisdxbjUxbhURQt08nKKj/EzhEnNA1xbDWOGYubHrBTTuPLETgxmm7ZgBkdj+IFYShcD Wdw3ipdaTmNO0vF+jobTIXEDBs1i7PQXob2TR863gRL8DW5LMvbUhxL2c/Gw4qqe+YHoN cfZravvZror1AM8CcP5/su6aYrEW28ey3oSLqhCQHltRxcd+JeaZ3RucDDiK1CcirXXuW C+UZCACVo1BQxYA4K5UqEfP7J7+sQNt8YGIAHL3PsXjrTltBAinEvJQVlaEUm1pTOfKAW j1RcCDAQ0rr8Gn/VzSB5+VKYEiL7JL4CS86cU6u1UfWS4uvPTwedaTw2iatS9aXm2Pg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794366825; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:MIME-Version:Content-Transfer-Encoding; bh=phQVKZmesdUoM78efvClfyyt5KXbDh+jIA8DftB/3Vo=; b=bMBbCrpYOEaJtLx9gFGUGdY2xykGi7wO9ZEyaorTnbNXTE3kFjz0UFv2mJSz0A6BIpSb OAVQDnHy175xyjUaD2Evkp09yZE1DqTfjsFZNoTFbRdkhuHnbegMX1C421r0OH625sRNp o+Gj6TYa7KGpaoexD7qtx0Tbm1Qkt99C80XmneC6Rt+NWOo9uKKyPjTQdnNCFV+dHSqAY cWj/vOJBNB/g2KeeuxjVDJ1MZYC+LTvmRD01J37FPrLB02/u/zAV+6Px7xQoVhXIBGYN/ TdUIrh6hA7sqzP8pPT9irQldUa+Ha0iaBLHK9HomaObdWUj0CGu6d/cifXh8t/p/LCg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=BlQx2TyE; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 38E50606A31C for ; Wed, 11 Nov 2026 03:13:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=BlQx2TyE Received: by smtp.kernel.org (Postfix) with ESMTPSA id 64D3A1F0093C; Wed, 11 Nov 2026 03:13:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794366825; bh=phQVKZmesdUoM78efvClfyyt5KXbDh+jIA8DftB/3Vo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=BlQx2TyEwjInQejxFiWFm75RykWvb/veFxXO9w8EHzpkwNO9NLu2rI+sKmkMUAtXW KEyDNwVMYMidK/K3IcUspgoUGoxrJ71gSEK7YazpX50iX3b/K7bTzhn5bVP1JMy6+8 DkBGrz2Z1Q9dtQhZiikCbn6ZkWke7oGMU+yEuf3h6Rgs6KksZitMU4YDI7Dl14endN cV6SXfEiu74X/c+er5N79qwEghLCR76D3fEQiTSfqIfKC9TWs9uqlMK5gSG0yzZiWD ZCAlAoATikj2p3+4PIjeUCmo/2VQ/1pLyUzOgYiOQGTN3JzVbrFbelKX5gHpg18/MB /FkUBo+pnxwQA== From: Sasha Levin To: stable@vger.kernel.org Cc: Armaan Sandhu , Andrew Morton , Leizhen Zhang , Andy Shevchenko , Sasha Levin Subject: [PATCH 6.12.y 2/2] lib/cmdline: fix get_options() count and overflow with large ranges Date: Tue, 10 Nov 2026 22:13:41 -0500 Message-ID: <20261111031318.849711-2-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20261111031318.849711-1-sashal@kernel.org> References: <20261107052511-failed-6.12-5d72266218b1@kernel.org> <20261111031318.849711-1-sashal@kernel.org> X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: Armaan Sandhu [ Upstream commit 5d72266218b1c4dd2917f1df2b86f3b0e0a605c9 ] get_range() stops writing once the array is full, but get_options() still advances its index by the whole range. So "1-100" parsed into four ints reports 99 numbers, and a range like "0-2147483647" wraps the index negative and writes outside the array. Stop once a range fills the array, bail out in validation mode before the count overflows, and saturate the range length in get_range(). Add KUnit cases; without the fix "0-2147483647" panics the test kernel. Only root can supply this input, so this is a robustness fix. [akpm@linux-foundation.org: add additional test case from Leizhen] Link: https://lore.kernel.org/20261005213945.359905-1-armaan.sandhu0504@gmail.com Fixes: 22f2e2801799 ("[PATCH] get_options to allow a hypenated range for isolcpus") Signed-off-by: Armaan Sandhu Signed-off-by: Andrew Morton Reported-by: Leizhen Zhang Reviewed-by: Leizhen Zhang Cc: Andy Shevchenko Cc: Signed-off-by: Sasha Levin --- lib/cmdline.c | 13 ++++++++++++- lib/cmdline_kunit.c | 39 +++++++++++++++++++++++++++++++++++++++ 2 files changed, 51 insertions(+), 1 deletion(-) diff --git a/lib/cmdline.c b/lib/cmdline.c index 90ed997d95701..f5dc59b3548e9 100644 --- a/lib/cmdline.c +++ b/lib/cmdline.c @@ -11,6 +11,7 @@ #include #include +#include #include #include @@ -26,7 +27,9 @@ static int get_range(char **str, int *pint, int n) (*str)++; upper_range = simple_strtol((*str), NULL, 0); - inc_counter = upper_range - *pint; + /* Keep the sign of the result when the difference doesn't fit */ + if (check_sub_overflow(upper_range, *pint, &inc_counter)) + inc_counter = upper_range < *pint ? -1 : INT_MAX; for (x = *pint; n && x < upper_range; x++, n--) *pint++ = x; return inc_counter; @@ -122,6 +125,14 @@ char *get_options(const char *str, int nints, int *ints) range_nums = get_range((char **)&str, pint, n); if (range_nums < 0) break; + /* The range didn't fit, so the array is full */ + if (!validate && range_nums > n) { + i = nints; + break; + } + /* Leave room for the upper number of the range */ + if (range_nums >= INT_MAX - i) + break; /* * Decrement the result by one to leave out the * last number in the range. The next iteration diff --git a/lib/cmdline_kunit.c b/lib/cmdline_kunit.c index af44ae9e92c3e..74c4b5ea32250 100644 --- a/lib/cmdline_kunit.c +++ b/lib/cmdline_kunit.c @@ -139,6 +139,44 @@ static void cmdline_test_range(struct kunit *test) } while (++i < ARRAY_SIZE(cmdline_test_range_strings)); } +static const struct { + const char *in; + int parsed[4]; + int validated; +} cmdline_test_range_overflow_cases[] = { + { "1-100", { 3, 1, 2, 3, }, 100, }, + { "1,5-100,7", { 3, 1, 5, 6, }, 98, }, + { "1-2147483646", { 3, 1, 2, 3, }, 2147483646, }, + { "0-2147483647", { 3, 0, 1, 2, }, 0, }, + { "-5-2147483647", { 3, -5, -4, -3, }, 0, }, + { "2147483647--5", { 0, 2147483647, }, 0, }, + { "1,0-2147483647", { 3, 1, 0, 1, }, 1, }, +}; + +static void cmdline_test_range_overflow(struct kunit *test) +{ + unsigned int i, j; + + for (i = 0; i < ARRAY_SIZE(cmdline_test_range_overflow_cases); i++) { + const char *in = cmdline_test_range_overflow_cases[i].in; + const int *e = cmdline_test_range_overflow_cases[i].parsed; + /* Two guard elements past the array handed to get_options() */ + int r[ARRAY_SIZE(cmdline_test_range_overflow_cases[0].parsed) + 2]; + int n; + + memset(r, 0, sizeof(r)); + get_options(in, ARRAY_SIZE(r) - 2, r); + for (j = 0; j < ARRAY_SIZE(r) - 2; j++) + KUNIT_EXPECT_EQ_MSG(test, r[j], e[j], "Pattern: %s at %u", in, j); + for (; j < ARRAY_SIZE(r); j++) + KUNIT_EXPECT_EQ_MSG(test, r[j], 0, "Pattern: %s out of bound at %u", in, j); + + get_options(in, 0, &n); + KUNIT_EXPECT_EQ_MSG(test, n, cmdline_test_range_overflow_cases[i].validated, + "Pattern: %s (validated)", in); + } +} + static void cmdline_test_next_arg_quoted_value(struct kunit *test) { char in[] = "foo=\"bar baz\" qux=1"; @@ -203,6 +241,7 @@ static struct kunit_case cmdline_test_cases[] = { KUNIT_CASE(cmdline_test_lead_int), KUNIT_CASE(cmdline_test_tail_int), KUNIT_CASE(cmdline_test_range), + KUNIT_CASE(cmdline_test_range_overflow), KUNIT_CASE(cmdline_test_next_arg_quoted_value), KUNIT_CASE(cmdline_test_next_arg_bare_quote_regression), KUNIT_CASE(cmdline_test_next_arg_mixed_tokens), -- 2.53.0