From patchwork Sun Nov 12 09:53:53 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ronald Monthero X-Patchwork-Id: 13453319 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (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 DB4186FCE for ; Sun, 12 Nov 2023 09:54:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="h1tmaTEa" Received: from mail-wm1-x32b.google.com (mail-wm1-x32b.google.com [IPv6:2a00:1450:4864:20::32b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8E28A2D62; Sun, 12 Nov 2023 01:54:34 -0800 (PST) Received: by mail-wm1-x32b.google.com with SMTP id 5b1f17b1804b1-4079ed65471so28067715e9.1; Sun, 12 Nov 2023 01:54:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1699782873; x=1700387673; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=4Y+xqbrN1WZa/CB0XAzBxnbgNyp0CPoCcb3whiJBwOM=; b=h1tmaTEap+cEWHjp0IT7aJ7J11vjnilX0zeP1BDNIx9ZauAd/GnQUWe5WtSe4NiuDs S0dftR+z2qyfDZ2qgHyVZMtH6ZjPN+cwsYoaUEZ4Rf7pC3xrfrZGioP/Z0hlgCUk8eO5 uRXRI45/1JXHUFmy/HQAc0ObgwxNLB5bkFdGcxNIJhSOjyecMixAV+t9upAw8ql5iRGg 1gtlGPcpy5hC0P7QRpgvJxcQ9hp2caKoBWbwN7QbM60USDQusONerNkmYXO8XhQswzF9 tXZgRyfAKIOUbX48heQVBm3tWOu3TS10d3G3uEfIa/s+JYkdCWEFjORchr+3odCQHqqW WI3A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1699782873; x=1700387673; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=4Y+xqbrN1WZa/CB0XAzBxnbgNyp0CPoCcb3whiJBwOM=; b=adOumkhkKkF8WrxHMGy1oTPjoNczzSgsBfm1JL0wqw8aAdH5MceldBr+MJOrhPzOs5 xD7u7Xqa8Gv9GBIPGddgezCcaYE5D5xYvDXVjYXbs7VW063KPP0iGo/a1WaF5lNCxMUB UiztQ/XCSeVOHExO62kSWjQJ8x80BazhdW7b+8mqSWyf7p/bgdj0vSEgib1vrqnNI/N0 RUuhdnZx7kP0GKOIR38V0rvqNYFq+qH5DtCCs4NsAu6ZjVIlMwF/fnOUiu8WBgp8wVlv cNUvz1yxfRnZ4yHrofKTLl9kv4CRP86iMZJE1YxicllXCVzAXHfsM3tBR09Xb4XKaRsr gvVA== X-Gm-Message-State: AOJu0YwvGTscYj+7tgoaOtPXjjTixk6d8aEWKV5OtcRIGB9F9ylyzpoo cx+syQ0BcFylzWfqVS5Lozc= X-Google-Smtp-Source: AGHT+IFhdvWQPiABEirvH8ajDQ/MWsIvLSNfMwdx+zFoWJPmRJ2z1VQ0IEmCdwejJCxks9UbmV1IRQ== X-Received: by 2002:a05:600c:d8:b0:405:4a78:a890 with SMTP id u24-20020a05600c00d800b004054a78a890mr3175157wmm.8.1699782872537; Sun, 12 Nov 2023 01:54:32 -0800 (PST) Received: from eagle-5590.. ([91.196.221.26]) by smtp.gmail.com with ESMTPSA id w23-20020a05600c2a1700b003fe23b10fdfsm10200942wme.36.2023.11.12.01.54.28 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 12 Nov 2023 01:54:32 -0800 (PST) From: Ronald Monthero To: al@alarsen.net Cc: keescook@chromium.org, gustavoars@kernel.org, Ronald Monthero , linux-kernel@vger.kernel.org, linux-hardening@vger.kernel.org Subject: [PATCH] qnx4: fix to avoid panic due to buffer overflow Date: Sun, 12 Nov 2023 19:53:53 +1000 Message-Id: <20231112095353.579855-1-debug.penguin32@gmail.com> X-Mailer: git-send-email 2.34.1 Precedence: bulk X-Mailing-List: linux-hardening@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 qnx4 dir name length can vary to be of maximum size QNX4_NAME_MAX or QNX4_SHORT_NAME_MAX depending on whether 'link info' entry is stored and the status byte is set. So to avoid buffer overflow check di_fname length fetched from (struct qnx4_inode_entry *) before use in strlen to avoid buffer overflow. panic context [ 4849.636861] detected buffer overflow in strlen [ 4849.636897] ------------[ cut here ]------------ [ 4849.636902] kernel BUG at lib/string.c:1165! [ 4849.636917] invalid opcode: 0000 [#2] SMP PTI .. [ 4849.637047] Call Trace: [ 4849.637053] [ 4849.637059] ? show_trace_log_lvl+0x1d6/0x2ea [ 4849.637075] ? show_trace_log_lvl+0x1d6/0x2ea [ 4849.637095] ? qnx4_find_entry.cold+0xc/0x18 [qnx4] [ 4849.637111] ? show_regs.part.0+0x23/0x29 [ 4849.637123] ? __die_body.cold+0x8/0xd [ 4849.637135] ? __die+0x2b/0x37 [ 4849.637147] ? die+0x30/0x60 [ 4849.637161] ? do_trap+0xbe/0x100 [ 4849.637171] ? do_error_trap+0x6f/0xb0 [ 4849.637180] ? fortify_panic+0x13/0x15 [ 4849.637192] ? exc_invalid_op+0x53/0x70 [ 4849.637203] ? fortify_panic+0x13/0x15 [ 4849.637215] ? asm_exc_invalid_op+0x1b/0x20 [ 4849.637228] ? fortify_panic+0x13/0x15 [ 4849.637240] ? fortify_panic+0x13/0x15 [ 4849.637251] qnx4_find_entry.cold+0xc/0x18 [qnx4] [ 4849.637264] qnx4_lookup+0x3c/0xa0 [qnx4] [ 4849.637275] __lookup_slow+0x85/0x150 [ 4849.637291] walk_component+0x145/0x1c0 [ 4849.637304] ? path_init+0x2c0/0x3f0 [ 4849.637316] path_lookupat+0x6e/0x1c0 [ 4849.637330] filename_lookup+0xcf/0x1d0 [ 4849.637341] ? __check_object_size+0x1d/0x30 [ 4849.637354] ? strncpy_from_user+0x44/0x150 [ 4849.637365] ? getname_flags.part.0+0x4c/0x1b0 [ 4849.637375] user_path_at_empty+0x3f/0x60 [ 4849.637383] vfs_statx+0x7a/0x130 [ 4849.637393] do_statx+0x45/0x80 .. Signed-off-by: Ronald Monthero --- fs/qnx4/namei.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/fs/qnx4/namei.c b/fs/qnx4/namei.c index 8d72221735d7..825b891a52b3 100644 --- a/fs/qnx4/namei.c +++ b/fs/qnx4/namei.c @@ -40,6 +40,13 @@ static int qnx4_match(int len, const char *name, } else { namelen = QNX4_SHORT_NAME_MAX; } + + /** qnx4 dir name length can vary, check the di_fname + * fetched from (struct qnx4_inode_entry *) before use in + * strlen to avoid panic due to buffer overflow" + */ + if (strnlen(de->di_fname, namelen) >= sizeof(de->di_fname)) + return -ENAMETOOLONG; thislen = strlen( de->di_fname ); if ( thislen > namelen ) thislen = namelen;