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 ADA323E2AD6; Wed, 30 Sep 2026 19:28:30 +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=1790796511; cv=none; b=LxClRKKEUQK7Vhp7GZGcHwdmrihH6E5coXGsUP0UNm9oEB4IlwhhARoQ7VbI+aEB5U7Vf6FpAm9og1CtkaEfG1s3cbmcj32TTX6nuR7bkNHa93asWtoaJIDzT7kwphO/8sIjWTdKQ1hlEdzvAiFh4W9WBM01cUrE6xZnk0fP84Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790796511; c=relaxed/simple; bh=p1csdwE9tP4WdKe/18enRTiA1u5NupPJT+VYWcpmrmU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fotVPWO4At/y8RGtc4FURncGbG1swVHCxUclNNbyw1BqzdFu+FwieQG4y1Lr4LJSFHcZJRhKKMJ5Tzb0iRviRDLxtu5l1drpEP0lsN9BM9xMIgMNn+BjY6wsgVSr45M5ShzjF13XdDotd287fk6Re434j9huKSOIKqG04a5Doxo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=QiS9XzrO; 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="QiS9XzrO" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 143E31F000FF; Wed, 30 Sep 2026 19:28:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790796510; bh=UTXpKZh7F7q/pja6HtH3NyBfehXNnhn5Vi05HXLfRik=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=QiS9XzrOY2Vq94IsMeQlIXsDhzykzD4YnT5aYHCuYUILQ0eGMMs9/vRLni+STxPzl TRBPQsar6uZVRhIinbJS6zMZbVJUJ1b8+ITLFIZ7820M088CpxVL3NHAaaLrZK7B97 0tAPsoOp3auKP6GLOZNf7PsCjfGl098HvV5s3n3s= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Frank Sorenson , David Howells , Paulo Alcantara Subject: [PATCH 6.6 0938/1193] smb: client: fix potential OOB read in smb3_enum_snapshots() Date: Wed, 30 Sep 2026 17:27:02 +0200 Message-ID: <20260930152455.080745295@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260930152434.301151190@linuxfoundation.org> References: <20260930152434.301151190@linuxfoundation.org> User-Agent: quilt/0.69 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 6.6-stable review patch. If anyone has any objections, please let me know. ------------------ From: Frank Sorenson commit 4775c3b7a597907e0b97556c7986fda238a377ae upstream. If snapshot_array_size is smaller than GMT_TOKEN_SIZE, smb3_enum_snapshots() sets ret_data_len to sizeof(struct smb_snapshot_array) without verifying the actual length of the server's reply. Because SMB2_ioctl() places no lower bound on the server-supplied OutputCount and allocates retbuf to exactly that length, a short reply results in ret_data_len exceeding the size of retbuf. The subsequent copy_to_user() then reads past the end of retbuf, leaking adjacent slab memory to userspace. The subsequent clamp check is ineffective as it only reduces ret_data_len. Fix this by rejecting replies shorter than sizeof(struct smb_snapshot_array) with -EIO. Note that the bound is set to the 12-byte struct size rather than the 16-byte MIN_SNAPSHOT_ARRAY_SIZE defined in MS-SMB2 3.3.5.15.1, because 12 bytes is exactly what copy_to_user() attempts to read. Fixes: e02789a53d71 ("smb3: enumerating snapshots was leaving part of the data off end") Cc: stable@vger.kernel.org Signed-off-by: Frank Sorenson Reviewed-by: David Howells Signed-off-by: Paulo Alcantara Signed-off-by: Greg Kroah-Hartman --- fs/smb/client/smb2ops.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -2190,8 +2190,14 @@ smb3_enum_snapshots(const unsigned int x * and retry the ioctl again with larger array size sufficient * to hold all of the snapshot GMT tokens on the second try. */ - if (snapshot_in.snapshot_array_size < GMT_TOKEN_SIZE) + if (snapshot_in.snapshot_array_size < GMT_TOKEN_SIZE) { + if (ret_data_len < sizeof(struct smb_snapshot_array)) { + rc = -EIO; + kfree(retbuf); + return rc; + } ret_data_len = sizeof(struct smb_snapshot_array); + } /* * We return struct SRV_SNAPSHOT_ARRAY, followed by