From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pz2-f40.google.com (mail-pz2-f40.google.com [74.125.228.40]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4C982371CF8 for ; Wed, 30 Sep 2026 03:16:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.228.40 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790738170; cv=none; b=gt/2kxFL6vtYi1M0quhHnPT8madvi+fpsnLbrou/MwXY3O9krPZGSqVPoUMzel0nZIMPzk4fEuCjUJbeH04thc5nBb1Gde+mgdH3nQ4AQccURmqvtyVdoIlko+szHum/8T5GzdPtMthmjSec0EJ6kXIbkQ9r6S9XPOoqY4WtZjI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790738170; c=relaxed/simple; bh=8wNFnaCc5+jMJWBgF5mE0Q+7753dPekI7+Vvl9kv3j4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=XZqQvkPoIccov0MuoQlkre4A0uS20IITIoT32KCF6H925llq+T11qSJc17vE4/F8Sc3r5U/R9AydnSsl6AY/KImjNnBhreWuVNcbNJFi3d7QQ4A2eh+SxTTd5SQbC6JWZcr+3fSgK1iv8LL2HJHtIyov7EvBcb9z8IUt65cjl6Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=rZENIbVL; arc=none smtp.client-ip=74.125.228.40 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="rZENIbVL" Received: by mail-pz2-f40.google.com with SMTP id 41be03b00d2f7-cc750a1482fso2750876a12.2 for ; Tue, 29 Sep 2026 20:16:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1790738167; x=1791342967; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to:content-type; bh=aeIWmkzMqAkIeZrxz8PymGN696feWU6nZ+MlW18uxhs=; b=rZENIbVL0hyFMkPI8F5qzoSdsjG8HG6WiDE/Hch/ife/F7zd7qXZV+NMlFgxdMC+Xm OdZytzy20vzVOl+4+ec6K0OFKVMu91NATNNGKEzDhqh6nIQqQvVj0V0qupzQqKw49ih3 CFj+Qm4Z3Lu+Bo2L1ju0NC7M79MMcMGK/lnpk9uwrerOJSEE1MCCqUsaFtLbP4dTf0U3 gX57y/M47O+t4s24CSrYI7mTD/B0Ygws5wjCW4rC8sufE9v5qaPFtFPOqJDatKo9Vv7i CzZXtYvD0s7wlM68F5kSwHKi5fkydJztSjp2sSNvzC7VDYJPbYtLzp2Kk7Ml/37GcM6E YP1Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1790738167; x=1791342967; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-gg:x-gm-message-state:from :to:cc:subject:date:message-id:reply-to:content-type; bh=aeIWmkzMqAkIeZrxz8PymGN696feWU6nZ+MlW18uxhs=; b=tUo6lwZv8qQKTwgu7tfEOu1EIlE13DrVig8oKbPSu679ltPebrbyUZ/oREvGBOHrJ8 PEdBc7Id2lKWcLHDF+HD7jy27XJCvjNL2SsiHYh1HE3Z5H8SGa07xR5hBvlRIBA0eKpe DmQgPqfcXNOZzjGyrhcRYWOpJk6lLMHSV/j/6dy3xA7GIfxfJU5n87DC0i4wkwshn0MY j+b5BxRV7hUTOPBWmrwSLckSQN6Q/NMGHmbwwDvi8rK9tazKRJ16mGXGv6HLoB7JPIYn mkMUkxNDvkxc6K92EPyyPdGbQ2YlqJ+4TifYv4e9mJ1cSqK1ZdatuvOl6i0Wu6pdu7Ee gUpQ== X-Forwarded-Encrypted: i=1; AKwUvBzV0sh/xlx41HlDCuuSDe7IVFark2FtBMOFRy/nTwv7H9Krl9PuuRrMnI1JU7l6cgwwws2rM0zq12XbMys=@vger.kernel.org X-Gm-Message-State: AFq9FYJzGLhPSqs/wn0+oiUtfVjAAEaNWPgG6HBb/bnf8QjAdV5ERqyQ O9jJfAZvkEGf0C5ssuKHZdcqsjb2MkbO2vI7a3krq2q45ihjEGrqiYmM X-Gm-Gg: AYBFou1NiICfRm9eodUO6p996pwYO0FSAusysHRq5RvSuCawe/vY/FEL1K7oVBvJqdi hHh+nqNXObcvawW4QgBy9gzMvZeLAFLB0tdqrx4gmnaYszxuK15Pziqe8kgLCIoGimQG4aB3Mbj Ym025Y996wZw0wzC+UxP28+vQ/L0MLNuPZUm2jDEjiNpZPngpETIqgdkeR3ifqLJWO8UGzAKndK XF3W0uz1wLWFTYRlAMj7yCOXrvT1bTH2h6pc56FUqRI8JDKmmawPZOF/FKLkV3re7A5ZgQ6v0M4 m01cqZQ+ZFFiNkQdTT0AIrc0lSnxqQ2hek/iPCNf+xmkf+B1Gi96pmiRd8ATFkiyodIkpeuZ7LM CW3Z6XBaGGHj5TCdRA3uQGXlr5IXM5bHFFTVdkuwkuiPX3rhQ9hYNdirBf4ZEQ/BRsenjCRpMCV +XKnMfjZH6dXaUrBzkAiN+YOMD2NavcgvZpWaxCMJi01/TNiXGcmIZnjT64Eg1795hXsX0SQPLv 7iIrHBeI6UmFqYbh9ssi14+OjOtj3AyTazqp1NHFVC9vm1R45jYkxkRk1yOsSoXJXIYCLJXNlJH uzmpFPRAZhoEpPZ24j6A X-Received: by 2002:a17:90a:ec8e:b0:3a2:aec0:6bd5 with SMTP id 98e67ed59e1d1-3a4d193fc3fmr76912a91.57.1790738167369; Tue, 29 Sep 2026 20:16:07 -0700 (PDT) Received: from phui-2.c.googlers.com.com (25.187.82.34.bc.googleusercontent.com. [34.82.187.25]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3a4ce1c9045sm588743a91.12.2026.09.29.20.16.06 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 29 Sep 2026 20:16:06 -0700 (PDT) From: Hui Peng To: Anders Larsen Cc: Matthias Goergens , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Hui Peng Subject: [PATCH v4 1/6] qnx6: validate di_filelevels in qnx6_iget() before accessing level pointers Date: Wed, 30 Sep 2026 03:15:59 +0000 Message-ID: <20260930031604.70544-2-benquike@gmail.com> X-Mailer: git-send-email 2.56.0.rc1.315.gc6ed9934b7-goog In-Reply-To: <20260924073920.2782917-1-benquike@gmail.com> References: <20260924073920.2782917-1-benquike@gmail.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 In qnx6_iget(), raw_inode->di_filelevels is read from disk without upper bounds checking. If raw_inode->di_filelevels exceeds QNX6_PTR_MAX_LEVELS (defined as 5 in include/linux/qnx6_fs.h), qnx6_block_map() performs out-of-bounds reads past di_block_ptr when dereferencing indirect tree levels. Validate raw_inode->di_filelevels against QNX6_PTR_MAX_LEVELS in qnx6_iget() and return -EIO if it exceeds 5. Tested in QEMU against tip of mainline commit 62f4c998b297 ("Merge tag 'parisc-for-7.3-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux") using a loop-device reproducer mounting a crafted QNX6 image with di_filelevels = 20: on the unfixed kernel, mounting triggered a buffer_head refcount underflow warning ("VFS: brelse: Trying to free free buffer"); whereas with this fix applied, qnx6_iget() cleanly rejects the corrupted inode with -EIO and logs "qnx6: bad filelevels 20 (max 5) on dev loop0, inode 1". Fixes: 5d026c724220 ("fs: initial qnx6fs addition") Cc: stable@vger.kernel.org Assisted-by: LLM Signed-off-by: Hui Peng --- Changes in v4: - Rebased cleanly onto upstream mainline commit 62f4c998b297. - Added QEMU test procedure and verification details in commit message body. - Updated commit description to state QNX6_PTR_MAX_LEVELS is 5 as noted by Matthias Goergens. fs/qnx6/inode.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/qnx6/inode.c b/fs/qnx6/inode.c index a15bb03f0ec3..e61c33f2e146 100644 --- a/fs/qnx6/inode.c +++ b/fs/qnx6/inode.c @@ -561,6 +561,14 @@ struct inode *qnx6_iget(struct super_block *sb, unsigned ino) sizeof(raw_inode->di_block_ptr)); ei->di_filelevels = raw_inode->di_filelevels; + if (ei->di_filelevels > QNX6_PTR_MAX_LEVELS) { + pr_err("bad filelevels %u (max %u) on dev %s, inode %u\n", + ei->di_filelevels, QNX6_PTR_MAX_LEVELS, sb->s_id, ino); + folio_release_kmap(folio, raw_inode); + iget_failed(inode); + return ERR_PTR(-EIO); + } + if (S_ISREG(inode->i_mode)) { inode->i_fop = &generic_ro_fops; inode->i_mapping->a_ops = &qnx6_aops; -- 2.55.0.1082.g2b9226bbc0-goog