From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794060822; b=fgcyOYtbK4m1MlQKlGrMeu+1/YwlNPk9A9JsiyHzpXPZQEFYEfpsnyxCKHDBsDgosyDX 59YVtok38KDA9ravylAV2i4UBnMGYqbk8kWd581ZcSJv4mT93L2hnNI6sEMIC5Esn1+QM lTiu4/a9s7GOfz+DAl17tTLTF/pdvLKLIXTz58G1eH7RUlwxWiI16xmnCGC8m+AmN9DQG 6bRh8k7IS4R03t+WTPOgVCGDX7jBKdjfp/z7Sh088JaikFqAjFUAN8O1dQdghS8Rqlsw7 znoFn1jlYnW4k0jIKhAq2Sdk5kmv98DBu9Z0oFqkwtJP7M7OzyoQWBFx1Z2ha8QqQjw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794060822; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=VkLzG+XQAaNH/I9bdrIk2PqEZqeKcaao8PP56gOgy44=; b=I4LsrnMQxkhFuLfeR0r0VfEyuY+Q65gWuVzdUMnzCo2p+fwPMqfuxXS6NvmwW0AaeuHe 6w1XPy0vDp40J5KwyYUZdWxAfIs3GwSYTEUY0fFw97Mfyto9JvQ8MCCOEZ97E3owWF57c siEoJlTDlA+/mDvr1msso26/KaDK3i//uDEIHbSqQGzSDICo9Ua5oysZqqo3zUVjnqWAU gc9VbZYCpv4RkeMROc8d6a1VFE1V/2PcLtjWupq/61nBGjXZyvSDEDa3w61y1Ma6ZFXKw Vkw7xzmDWcAylPCsXlBXiQxWo380fG1EIpxInyfO65EVpUnuWJ86A4OH8MuzHWbu/cA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=1XwJui4o; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4BDDE606A326; Sat, 7 Nov 2026 14:13:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=1XwJui4o Received: by smtp.kernel.org (Postfix) with ESMTPSA id E29F01F0089F; Sat, 7 Nov 2026 14:13:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1794060822; bh=VkLzG+XQAaNH/I9bdrIk2PqEZqeKcaao8PP56gOgy44=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=1XwJui4oLeoRtUBUar0cLcMsuWSjUVgW1Xfn2VNutzZzbOxSn/a+TnXmRAcrGNrw+ i7dJK1uvpZiYQrgPkIrmCIa1UBC//wx5Ko4G0D5WzLk+pdhOiiXBW5C+oU2kBKv0bn RQ26zwF3hVyVS4YIbBnaR4A+XiVtdqbfzIhYwc4k= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Jay Vadayath , Jan Kara , Sasha Levin Subject: [PATCH 6.12 0219/1536] udf: bound lengthAllocDescs from unallocated space entry Date: Sat, 7 Nov 2026 08:37:15 -0500 Message-ID: <20261107135003.812365694@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261107134957.653319350@linuxfoundation.org> References: <20261107134957.653319350@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jay Vadayath [ Upstream commit b8228f59dc58aea06dc024efd8f64c2d048c4578 ] udf_read_inode() copies the on-disk lengthAllocDescs field of a USE (unallocSpaceEntry) inode into iinfo->i_lenAlloc without checking that it fits in the i_data buffer that is subsequently allocated for the inode. udf_count_free_table(), called from udf_statfs(), then walks the allocation descriptor array up to i_lenAlloc bytes, so a crafted UDF image with lengthAllocDescs larger than (blocksize - sizeof(struct unallocSpaceEntry)) causes udf_get_fileshortad() to read past the end of the kmalloc'd i_data buffer. KASAN report from mounting a crafted UDF image and calling statfs() from an unprivileged process: BUG: KASAN: slab-out-of-bounds in udf_get_fileshortad+0x126/0x130 Read of size 4 at addr ffff8880042137d8 by task poc/65 Call Trace: dump_stack_lvl+0x53/0x70 print_report+0xce/0x610 kasan_report+0xce/0x100 udf_get_fileshortad+0x126/0x130 udf_current_aext+0x3c4/0xa10 udf_next_aext+0x241/0x440 udf_statfs+0xb7d/0x11c0 statfs_by_dentry+0x117/0x1e0 user_statfs+0xac/0x130 __do_sys_statfs+0x80/0xe0 do_syscall_64+0x102/0x5a0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Reject USE inodes whose lengthAllocDescs would place descriptors past the end of the i_data buffer, mirroring the checks the rest of the UDF code performs on descriptor lengths. This bug was discovered by Artiphishell's vTriage pipeline, which generated a userspace reproducer that reliably triggers the KASAN report on an unpatched kernel. The fix below was drafted with the Claude coding assistant; a userspace reproducer (and the crafted UDF image) is available on request. Assisted-by: LLM Signed-off-by: Jay Vadayath Link: https://patch.msgid.link/20260717184021.13476-1-jay@artiphishell.com Signed-off-by: Jan Kara Signed-off-by: Sasha Levin --- fs/udf/inode.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/fs/udf/inode.c b/fs/udf/inode.c index 05eddd60e80a7..78a04b2cb820d 100644 --- a/fs/udf/inode.c +++ b/fs/udf/inode.c @@ -1481,6 +1481,10 @@ static int udf_read_inode(struct inode *inode, bool hidden_inode) iinfo->i_lenAlloc = le32_to_cpu( ((struct unallocSpaceEntry *)bh->b_data)-> lengthAllocDescs); + if (iinfo->i_lenAlloc > bs - sizeof(struct unallocSpaceEntry)) { + ret = -EFSCORRUPTED; + goto out; + } ret = udf_alloc_i_data(inode, bs - sizeof(struct unallocSpaceEntry)); if (ret) -- 2.53.0