From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 CDC2D320CA0; Mon, 18 Aug 2025 13:39:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755524370; cv=none; b=YEg0BrEFaoDPybH7PT8R5mzxlq6lpg/qAcG3AA5A0JRbprEmYjGc6lDmEoW+jMB6afHSLsF5cyGu6OSF69axednK65Eh5r2m9KKIaegkuH4+2XLmVlR2iKvUMLoJR7uHd+bDMATOMitxgCNhLOs+f1gOmZjrNJC/zh7x8EIkdbE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755524370; c=relaxed/simple; bh=DuMIwXnhghcZ1sYS4rLV5KGx4H3Hqq4vmLYMyxbugls=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cpNQ9c8JtiOtZv+6n10hhzxTcI7OnYaQuIinU1BAyK6oGmyQ6vnCBovvSsBX/fqUm1t4HNBynkWK2Ia8wqC/H6Q6nss4SpBr+EAYQbN/wdBpbc2I+8KOKZkO6FVNhGH5m0N6e6GA5n9F5wmSqhuPzrmb7qR0B8BmgHPxWPDTV44= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=txrGlX2I; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="txrGlX2I" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4D91EC4CEEB; Mon, 18 Aug 2025 13:39:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1755524370; bh=DuMIwXnhghcZ1sYS4rLV5KGx4H3Hqq4vmLYMyxbugls=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=txrGlX2IW98dksZ8bXY0sjTR5493f3VOeURvqzkMhNmjGv+56smpNr86pckFdrRLw /3XLpiQC51UAMlP/ZpH1BGzFVfy5oGcUUFKnRRJueGBaWy1gzg6l+p8mALsJDxri31 tG3dJBaNNvYANlq1bME+oj5uFVw6BHf/UQI6LpdY= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+c2f65e2801743ca64e08@syzkaller.appspotmail.com, Yi Liu , Nicolin Chen , Jason Gunthorpe Subject: [PATCH 6.15 451/515] iommufd: Prevent ALIGN() overflow Date: Mon, 18 Aug 2025 14:47:17 +0200 Message-ID: <20250818124515.780138745@linuxfoundation.org> X-Mailer: git-send-email 2.50.1 In-Reply-To: <20250818124458.334548733@linuxfoundation.org> References: <20250818124458.334548733@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jason Gunthorpe commit b42497e3c0e74db061eafad41c0cd7243c46436b upstream. When allocating IOVA the candidate range gets aligned to the target alignment. If the range is close to ULONG_MAX then the ALIGN() can wrap resulting in a corrupted iova. Open code the ALIGN() using get_add_overflow() to prevent this. This simplifies the checks as we don't need to check for length earlier either. Consolidate the two copies of this code under a single helper. This bug would allow userspace to create a mapping that overlaps with some other mapping or a reserved range. Cc: stable@vger.kernel.org Fixes: 51fe6141f0f6 ("iommufd: Data structure to provide IOVA to PFN mapping") Reported-by: syzbot+c2f65e2801743ca64e08@syzkaller.appspotmail.com Closes: https://lore.kernel.org/r/685af644.a00a0220.2e5631.0094.GAE@google.com Reviewed-by: Yi Liu Reviewed-by: Nicolin Chen Link: https://patch.msgid.link/all/1-v1-7b4a16fc390b+10f4-iommufd_alloc_overflow_jgg@nvidia.com/ Signed-off-by: Jason Gunthorpe Signed-off-by: Greg Kroah-Hartman --- drivers/iommu/iommufd/io_pagetable.c | 41 +++++++++++++++++++++-------------- 1 file changed, 25 insertions(+), 16 deletions(-) --- a/drivers/iommu/iommufd/io_pagetable.c +++ b/drivers/iommu/iommufd/io_pagetable.c @@ -70,36 +70,45 @@ struct iopt_area *iopt_area_contig_next( return iter->area; } -static bool __alloc_iova_check_hole(struct interval_tree_double_span_iter *span, - unsigned long length, - unsigned long iova_alignment, - unsigned long page_offset) +static bool __alloc_iova_check_range(unsigned long *start, unsigned long last, + unsigned long length, + unsigned long iova_alignment, + unsigned long page_offset) { - if (span->is_used || span->last_hole - span->start_hole < length - 1) + unsigned long aligned_start; + + /* ALIGN_UP() */ + if (check_add_overflow(*start, iova_alignment - 1, &aligned_start)) return false; + aligned_start &= ~(iova_alignment - 1); + aligned_start |= page_offset; - span->start_hole = ALIGN(span->start_hole, iova_alignment) | - page_offset; - if (span->start_hole > span->last_hole || - span->last_hole - span->start_hole < length - 1) + if (aligned_start >= last || last - aligned_start < length - 1) return false; + *start = aligned_start; return true; } -static bool __alloc_iova_check_used(struct interval_tree_span_iter *span, +static bool __alloc_iova_check_hole(struct interval_tree_double_span_iter *span, unsigned long length, unsigned long iova_alignment, unsigned long page_offset) { - if (span->is_hole || span->last_used - span->start_used < length - 1) + if (span->is_used) return false; + return __alloc_iova_check_range(&span->start_hole, span->last_hole, + length, iova_alignment, page_offset); +} - span->start_used = ALIGN(span->start_used, iova_alignment) | - page_offset; - if (span->start_used > span->last_used || - span->last_used - span->start_used < length - 1) +static bool __alloc_iova_check_used(struct interval_tree_span_iter *span, + unsigned long length, + unsigned long iova_alignment, + unsigned long page_offset) +{ + if (span->is_hole) return false; - return true; + return __alloc_iova_check_range(&span->start_used, span->last_used, + length, iova_alignment, page_offset); } /*