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b=bRNsxKJOljO5gDXhx6JeJ7EgfIrKkNy1wlrEml8OwkdMFWtKpUXIyHPf5Xt56FLdu Yh4CdBaXsOEmotMF9CW5zrSWv8agAviPGaa7gi8R8/Qza3a6u3R2HSizC51hGOEwpv hVVa71o44xjd1eH5nofJx0bOjWh8EuWIZ/xJgr4k= Received: from pek-lxu-l1.wrs.com ([111.198.228.153]) by newxmesmtplogicsvrszb9-1.qq.com (NewEsmtp) with SMTP id 356A180B; Tue, 09 Apr 2024 21:13:22 +0800 X-QQ-mid: xmsmtpt1712668402t5chgs1d7 Message-ID: X-QQ-XMAILINFO: OXHA96V41vMDBwhYwn7+OjcGgzli3xXJ2XDxO3wfyTlv9jhUGCma8gVWdIuDuN q8gbpT2OeHrZgo4KnPTxPoOXTrr+jLmUXj0dn/aqJHpzPeqeMTjHBAuN0Ppaas2adCVyxYG8CzzP aShYl/WjyuH6yN1aND/6KraaC/HtUP6aeTos6AFQLq8581MSBKOMLifVxFwoo0dY5wb9+3wNgRZR mWMTEqAHfhLji65ddxmzut9n3WMYXg6xtwqo2EhKBTJirEEM7gWwnufhWF+rqn1El5waws8qzkD3 v2iK2Uqx+7gDtlujVJsnZxgHj9CR2QIGXagyWTqYrQOab6SikTD0YFAqmRqGZIbggb8tdEA3XVYt sEM38BH5O0DeCrmU2e/XAZi3TXVDp1DSopwHTFDH6453LvFAPr1yxp1+Hb8iVNflHkldj1TIGKWk JBE/tFj+itxDdiMcNZdGAJyfW24sif6QqDgu9hhhUcULarS641sNTtVkNHaLrhS4P0QqG7JM+Dl0 1A7110ENLuwaAXUlw3v5kKQlOqyWSrLHVMxgNQBv37PiItIccuQOi3WlnpJgJG4sHge6V53Dv14Q oRMWgwZzeBHOs4T90fZkUumAEvwqvXDhJGmtQ3vylWnYIc5q3q6/TS7DIQ+U1ouG0UjLLk2Yda+D Ep1HJMpcBzjIrC11nLztBM1QPf3Ulj0x9Nymjk3UxP9iAkaDKQVYe1fpCSafoCQE62+oUJ1LkAyw gqCMrpHc3xP3aPnFaYcOept/8i+vSNNpkbhG4z2eLam1B74/1EVRkRG/B29iKOfo2sTw/K/7iGTV 4+iHzcS8Cw7OTRiUIbJQ83l54qY+i+UsnOW4zCetBiHCXeP+tq3wY4zkFHrScqMpgM1jNG6HkcSd rNT7gzJQcJDXWp0Zg4Ozbfls9tpNK2l2UVodLKdc2dDNZzLZXUQRU3edWQE2YB91oofgXma5d7oJ fGCC6//qsNs39ZvJXBNUPWLsza0clge7u8p3J1b85BJQ5wD5bN5astSCfIYgB5RJR39hNQaEgYF2 i2EQItu4zNgv6BoCSO X-QQ-XMRINFO: M/715EihBoGSf6IYSX1iLFg= From: Edward Adam Davis To: syzbot+9b8be5e35747291236c8@syzkaller.appspotmail.com Cc: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [bpf?] KMSAN: uninit-value in strnchr Date: Tue, 9 Apr 2024 21:13:23 +0800 X-OQ-MSGID: <20240409131322.4166944-2-eadavis@qq.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <0000000000009e2ff406130de279@google.com> References: <0000000000009e2ff406130de279@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit please test uini in strnchr #syz test https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 04b8076df253 diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c index 449b9a5d3fe3..54abc67c48c7 100644 --- a/kernel/bpf/helpers.c +++ b/kernel/bpf/helpers.c @@ -826,7 +826,8 @@ int bpf_bprintf_prepare(char *fmt, u32 fmt_size, const u64 *raw_args, u64 cur_arg; char fmt_ptype, cur_ip[16], ip_spec[] = "%pXX"; - fmt_end = strnchr(fmt, fmt_size, 0); + kmsan_unpoison_memory(fmt, fmt_size); + fmt_end = strnchrnul(fmt, fmt_size, 0); if (!fmt_end) return -EINVAL; fmt_size = fmt_end - fmt; -- 2.43.0