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 632CE53B5EE; Wed, 23 Sep 2026 14:53:23 +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=1790175204; cv=none; b=Ivig2VmPyec4Ow7rpCj6Pv0x8Wux+xJj/UwA5k+JBDiDnYNuwDcW3ZQjrZGKWCzkOiAYfpNZN2uQz8/Kk5ft/yTupOEBqw+inG20KRAKgoFzjx1UWBs1D3ATXQ1hXfhdzwDGLxshyB/jVKQA03QK8zLOu3FSjLf26vT3qri94L0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790175204; c=relaxed/simple; bh=3ISTjniQpDQXk7rFvsso3wLCabui9fSA7zyvOcoZ8/Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=oY3qBk3lvCo2ucIIFuhmJ1SBDUV9WQGW2auUD3NaHSxOCzVjAmr6LD1SzUIlQz//kpwPi5sPl4HxGaF6FAgw3ymBxJq3rHv4aFn6trTJhderl0JKoH+nmOxSLihOGOxbtf+zLI67rRlam0zmv467iU44j8VoDX3Azz7f0yvVRKo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=YMOX6kLF; 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="YMOX6kLF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 591E21F000FF; Wed, 23 Sep 2026 14:53:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790175203; bh=kO3CtRgs3ZSsKcAKjRXii/EU6g/izfifJtPDwBe2uKc=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=YMOX6kLFBcwcXb10bYyfdhGRw7p6JCpWlfoij26p3iaFAogkxVNg9dhQjYLftmrlb +EUPpTpPSAgUFlXgpz2aCdXaKIeKXYTU5LKfQ3i63xv+DjS3AQVGyjFUai3W9TP0O2 m66Fb7ehtHrcPXAVev1437kaic2kjepz7HxWpmRU= 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 6.18 352/398] smb: client: fix OOB struct field reads in move_smb2_ea_to_cifs() Date: Wed, 23 Sep 2026 16:07:06 +0200 Message-ID: <20260923140652.554066800@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260923140643.441954610@linuxfoundation.org> References: <20260923140643.441954610@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 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Frank Sorenson commit eeb5ef6083e1cefa2ef75041b5597ff228b8d7bb upstream. In move_smb2_ea_to_cifs(), the while (src_size > 0) loop condition is insufficient. It allows iteration to continue even if the remaining src_size is too small to contain a complete smb2_ea_info structure. Consequently, reads of ea_name_length and ea_value_length can occur out-of-bounds. Fix this by ensuring src_size >= sizeof(*src) before attempting to read any structure fields. Additionally, reject any next_entry_offset that is smaller than sizeof(*src) or that would advance the pointer beyond the available buffer. Note that for calls where the server returns a malformed EA list, the error returned to userspace changes from -ENODATA (getxattr) or -ERANGE (listxattr) to -EIO. This correctly signals a server protocol error rather than misleadingly indicating "attribute not present" or "output buffer too small". Fixes: 95907fea4fd8 ("cifs: Add support for reading attributes on SMB2+") 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 | 25 +++++++++++++++++-------- fs/smb/client/trace.h | 1 + 2 files changed, 18 insertions(+), 8 deletions(-) --- a/fs/smb/client/smb2ops.c +++ b/fs/smb/client/smb2ops.c @@ -1054,8 +1054,9 @@ move_smb2_ea_to_cifs(char *dst, size_t d char *name, *value; size_t buf_size = dst_size; size_t name_len, value_len, user_name_len; + u32 next_off; - while (src_size > 0) { + while (src_size >= sizeof(*src)) { name_len = (size_t)src->ea_name_length; value_len = (size_t)le16_to_cpu(src->ea_value_length); @@ -1110,14 +1111,22 @@ move_smb2_ea_to_cifs(char *dst, size_t d if (!src->next_entry_offset) break; - if (src_size < le32_to_cpu(src->next_entry_offset)) { - /* stop before overrun buffer */ - rc = -ERANGE; - break; + next_off = le32_to_cpu(src->next_entry_offset); + if (next_off < sizeof(*src) || src_size < next_off) { + cifs_dbg(FYI, "EA next_entry_offset %u out of range [%zu, %zu]\n", + next_off, sizeof(*src), src_size); + rc = smb_EIO2(smb_eio_trace_ea_next_offset, + next_off, src_size); + goto out; + } + src_size -= next_off; + src = (void *)((char *)src + next_off); + if (src_size > 0 && src_size < sizeof(*src)) { + cifs_dbg(FYI, "EA next_entry_offset %u left truncated entry (%zu bytes)\n", + next_off, src_size); + rc = smb_EIO2(smb_eio_trace_ea_next_offset, next_off, src_size); + goto out; } - src_size -= le32_to_cpu(src->next_entry_offset); - src = (void *)((char *)src + - le32_to_cpu(src->next_entry_offset)); } /* didn't find the named attribute */ --- a/fs/smb/client/trace.h +++ b/fs/smb/client/trace.h @@ -27,6 +27,7 @@ EM(smb_eio_trace_copychunk_overcopy_c, "copychunk_overcopy_c") \ EM(smb_eio_trace_create_rsp_too_small, "create_rsp_too_small") \ EM(smb_eio_trace_dfsref_no_rsp, "dfsref_no_rsp") \ + EM(smb_eio_trace_ea_next_offset, "ea_next_offset") \ EM(smb_eio_trace_ea_overrun, "ea_overrun") \ EM(smb_eio_trace_extract_will_pin, "extract_will_pin") \ EM(smb_eio_trace_forced_shutdown, "forced_shutdown") \