From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 60C9919D092 for ; Mon, 20 Jul 2026 14:26:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784557619; cv=none; b=XRlV0LjhfO52V+8jJYzR9A4776YovdS6Pey7XlgFKet4ve0IGrX5z1ZMa/kwGGm1eeYLxWTLGJqw/EXv27iGIKfYRoIIf+Dxj4v7ct/s+jtW+6bpKluTPJoh3cEIAhLsTL0/u37wcYBqURb+Y5AcZeP69QhrKgzs7UXzRomYNso= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784557619; c=relaxed/simple; bh=UcjI6E1TdZKjqqL6F+zOQg6dwyojXkKx+XigWAJdZaY=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=pZXbPKS8yPHCsANgJOCDfGP44VKCxnuhNMjpCv9UlDry1ERghoxbW8qU/yGu9KggOx9/Ot24L7+GeNC/GOnrDupk2h9zLMlnGLZEqRjp3XXxOlc5V+Njesc6s8Mck9+SqGKMEU1d+pIWIIfo98YnetJAEXHWb+3f+csWVe2apOU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=A8a+e0zY; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="A8a+e0zY" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7F10E1F000E9; Mon, 20 Jul 2026 14:26:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1784557618; bh=9MTz4bDURSGC0fD+khOBpPXiZLOBXWsf49/tv5I0Z14=; h=Subject:To:Cc:From:Date; b=A8a+e0zYdIL0989UzAv+QskGa1o52hr0Gp8fukz6a1oodqAHsXGQysyJnoXXRnG2H Yxns7uFm8V6IrM6sZszpuWeMrIs1IA8aNMbz8pmyKRK9Pw1JWydFqRV4/NycLuQyWx cABXC9lKHaVaIjEJKiIvtyHXrV9EC9CJFH2IYEKA= Subject: FAILED: patch "[PATCH] ntfs3: validate split-point offset in indx_insert_into_buffer" failed to apply to 6.1-stable tree To: michael.bommarito@gmail.com,almaz.alexandrovich@paragon-software.com Cc: From: Date: Mon, 20 Jul 2026 16:26:48 +0200 Message-ID: <2026072048-smudge-reselect-d44b@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x f1df9d771df47aa40de6d70949c28720ae1e430d # git commit -s git send-email --to '' --in-reply-to '2026072048-smudge-reselect-d44b@gregkh' --subject-prefix 'PATCH 6.1.y' 'HEAD^..' Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From f1df9d771df47aa40de6d70949c28720ae1e430d Mon Sep 17 00:00:00 2001 From: Michael Bommarito Date: Fri, 17 Apr 2026 18:57:12 -0400 Subject: [PATCH] ntfs3: validate split-point offset in indx_insert_into_buffer indx_insert_into_buffer() computes used = used1 - to_copy - sp_size; memmove(de_t, Add2Ptr(sp, sp_size), used - le32_to_cpu(hdr1->de_off)); where sp and sp_size come from hdr_find_split(). hdr_find_split() walks entries by le16_to_cpu(e->size) without validating that each step stays within hdr->used or that the size field is at least sizeof(struct NTFS_DE). index_hdr_check(), the on-load gatekeeper, only validates header-level fields (used, total, de_off) and does not walk per-entry sizes. A crafted NTFS image whose leaf INDEX_HDR reports used == total but contains one interior NTFS_DE with size = 0xFFF0 therefore passes validation, descends to indx_insert_into_buffer() through the ntfs_create() -> indx_insert_entry() path, and makes hdr_find_split() return an sp whose sp_size (0xFFF0) greatly exceeds the remaining bytes in the buffer. The u32 subtraction underflows and the memmove count becomes a near-4-GiB value, producing an out-of-bounds kernel write that corrupts adjacent allocations and panics the kernel. Reproduced on 7.0.0-rc7 with UML + KASAN via a crafted image and a single 'touch' inside the mounted directory; crash site resolves to fs/ntfs3/index.c at the memmove. Trigger requires only local mount of an attacker-supplied filesystem image (USB, loopback, or removable media auto-mount). Reject the split whenever the chosen sp plus its declared size already extends past hdr1->used. This is the minimal fix; it preserves the existing hdr_find_split() contract and relies on the same out: cleanup path as the pre-existing error returns. A prior OOB read in the very same indx_insert_into_buffer() memmove was fixed in commit b8c44949044e ("fs/ntfs3: Fix OOB read in indx_insert_into_buffer") by tightening hdr_find_e(), but that fix does not cover the split-point size field path addressed here: sp is returned by hdr_find_split(), not hdr_find_e(), and the underflow is driven by sp->size rather than hdr->used exceeding hdr->total. Fixes: 82cae269cfa9 ("fs/ntfs3: Add initialization of super block") Cc: stable@vger.kernel.org Reported-by: Michael Bommarito Assisted-by: Claude:claude-opus-4-7 Signed-off-by: Michael Bommarito Signed-off-by: Konstantin Komarov diff --git a/fs/ntfs3/index.c b/fs/ntfs3/index.c index 5868964e129c..ade276225999 100644 --- a/fs/ntfs3/index.c +++ b/fs/ntfs3/index.c @@ -1862,6 +1862,20 @@ indx_insert_into_buffer(struct ntfs_index *indx, struct ntfs_inode *ni, memcpy(up_e, sp, sp_size); used1 = le32_to_cpu(hdr1->used); + + /* + * hdr_find_split does not validate per-entry sizes, so a crafted + * NTFS_DE whose le16 size field is out of range can place sp such + * that (PtrOffset(hdr1, sp) + sp_size) exceeds used1. Without this + * guard the u32 'used = used1 - to_copy - sp_size' underflows and + * the subsequent memmove count becomes a near-4-GiB value, + * triggering an out-of-bounds kernel write. + */ + if (PtrOffset(hdr1, sp) + sp_size > used1) { + err = -EINVAL; + goto out; + } + hdr1_saved = kmemdup(hdr1, used1, GFP_NOFS); if (!hdr1_saved) { err = -ENOMEM;