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Howlett" , Nico Pache , Ryan Roberts , Dev Jain , Barry Song , Lance Yang , Usama Arif , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , linux-mm@kvack.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org References: <20260821114416.12255-1-anshumantewari123@gmail.com> Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: <20260821114416.12255-1-anshumantewari123@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Rspam-User: X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: B1419A0009 X-Stat-Signature: 6fwx8q1nddiaff8z4tddxuznw78xt7nh X-HE-Tag: 1787321949-823917 X-HE-Meta: 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 NZHkPlqz eckncuvsitUoF+nlypAszDU2Zinqjzi4LPyfTeAIAiY9QfYnuKqEVt/I3nswApv1039Ck2ntgO0L1Wm4KjCpCkTLHVB9FzH7nkiCviOSTyL54uyHSeskt9l869v/R1itRfWvYVGLDanYlWX5jK6vt0XUB3ptY53UbOJ3S2S9En9KTMFd3iSnacdfpMjb7v/RuFEcog8H/ub474DccBCZvCI76deaMGxh8sPIFc9y/1WoAKfcd41S9MncXBWZ4nJQS4+VqCfq71tUKGgVr8xeGttF0ds3QC3HKQjwUPxR3LksZs56ryyJk01kxCJZWz2mKYQr1adwj3wOb7+M6fHPXNhXA1uQkXoEoVH/4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 8/21/26 13:44, Anshuman wrote: > The return value of strdup() is never checked before being passed to > strsep() and strcmp(). If strdup() fails and returns NULL, strsep() > returns NULL as well, and the subsequent strcmp(NULL, "all") is > undefined behavior, likely causing a crash. In practice this is extraordinarily unlikely to ever fail. :) So I don't think we would ever experience this. > > Additionally, buf is never freed. strsep() advances the buf pointer > past the first token, so by the time buf would normally be freed, > the original pointer returned by strdup() has already been > overwritten and is no longer available. Given that parse_test_type() is called only once, nobody cares. > > Check strdup()'s return value and fail cleanly on allocation failure. > Keep a separate pointer to the original allocation so it can be > freed once buf is done being used, after all parsing has completed > successfully. > > Signed-off-by: Anshuman > --- [...] That's too much churn for something that is irrelevant in practice and makes the code more complicated. So the following is better I think: >From 36d525409eb16f56e667b2f979f2c6ef112ff235 Mon Sep 17 00:00:00 2001 From: "David Hildenbrand (Arm)" Date: Fri, 21 Aug 2026 15:57:57 +0200 Subject: [PATCH] selftests/mm: khugepaged: remove str_dup() usage We don't check str_dup() return value and never free it. While both things are irrelevant in practice, let's just work on argv[0] directly and avoid the str_dup(). Nobody after us needs these parts of the argv[0] string. Signed-off-by: David Hildenbrand (Arm) --- tools/testing/selftests/mm/khugepaged.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/mm/khugepaged.c b/tools/testing/selftests/mm/khugepaged.c index d3a53673e1f9..7520fc0483ac 100644 --- a/tools/testing/selftests/mm/khugepaged.c +++ b/tools/testing/selftests/mm/khugepaged.c @@ -1226,7 +1226,7 @@ static void parse_test_type(int argc, char **argv) return; } - buf = strdup(argv[0]); + buf = argv[0]; token = strsep(&buf, ":"); if (!strcmp(token, "all")) { -- 2.43.0 -- Cheers, David