From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from firstgate.proxmox.com (firstgate.proxmox.com [IPv6:2a01:7e0:0:424::9]) by lore.proxmox.com (Postfix) with ESMTPS id 05DA21FF16F for ; Fri, 15 Nov 2024 16:19:35 +0100 (CET) Received: from firstgate.proxmox.com (localhost [127.0.0.1]) by firstgate.proxmox.com (Proxmox) with ESMTP id E98F01839D; Fri, 15 Nov 2024 16:18:22 +0100 (CET) From: Dominik Csapak To: pve-devel@lists.proxmox.com Date: Fri, 15 Nov 2024 16:17:26 +0100 Message-Id: <20241115151749.633407-5-d.csapak@proxmox.com> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20241115151749.633407-1-d.csapak@proxmox.com> References: <20241115151749.633407-1-d.csapak@proxmox.com> MIME-Version: 1.0 X-SPAM-LEVEL: Spam detection results: 0 AWL 0.016 Adjusted score from AWL reputation of From: address BAYES_00 -1.9 Bayes spam probability is 0 to 1% DMARC_MISSING 0.1 Missing DMARC policy KAM_DMARC_STATUS 0.01 Test Rule for DKIM or SPF Failure with Strict Alignment SPF_HELO_NONE 0.001 SPF: HELO does not publish an SPF Record SPF_PASS -0.001 SPF: sender matches SPF record Subject: [pve-devel] [PATCH storage v6 04/12] ovf: improve and simplify path checking code X-BeenThere: pve-devel@lists.proxmox.com X-Mailman-Version: 2.1.29 Precedence: list List-Id: Proxmox VE development discussion List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: Proxmox VE development discussion Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: pve-devel-bounces@lists.proxmox.com Sender: "pve-devel" moves the filepath code a bit more closer to where it's actually used checks the contained path before trying to find it's absolute path properly add error handling to realpath instead of checking the combined ovf_path + filepath, just make sure filepath can't point to anythign besides a file in this directory by checking for '.' and '..' (slashes are not allowed in SAFE_CHAR_CLASS_RE) Signed-off-by: Dominik Csapak --- changes from v5: * reintroduce check for symlinks src/PVE/GuestImport/OVF.pm | 33 ++++++++++++++++++--------------- 1 file changed, 18 insertions(+), 15 deletions(-) diff --git a/src/PVE/GuestImport/OVF.pm b/src/PVE/GuestImport/OVF.pm index c7bff5f..966dcd1 100644 --- a/src/PVE/GuestImport/OVF.pm +++ b/src/PVE/GuestImport/OVF.pm @@ -220,15 +220,6 @@ ovf:Disk[\@ovf:diskId='%s']/\@ovf:capacityAllocationUnits", $disk_id); next; } - # from Disk Node, find corresponding filepath - my $xpath_find_filepath = sprintf("/ovf:Envelope/ovf:References/ovf:File[\@ovf:id='%s']/\@ovf:href", $fileref); - my $filepath = $xpc->findvalue($xpath_find_filepath); - if (!$filepath) { - warn "invalid file reference $fileref, skipping\n"; - next; - } - print "file path: $filepath\n" if $debug; - # from Item, find owning Controller type my $controller_id = $xpc->findvalue('rasd:Parent', $item_node); my $xpath_find_parent_type = sprintf("/ovf:Envelope/ovf:VirtualSystem/ovf:VirtualHardwareSection/\ @@ -244,22 +235,34 @@ ovf:Item[rasd:InstanceID='%s']/rasd:ResourceType", $controller_id); my $adress_on_controller = $xpc->findvalue('rasd:AddressOnParent', $item_node); my $pve_disk_address = id_to_pve($controller_type) . $adress_on_controller; + # from Disk Node, find corresponding filepath + my $xpath_find_filepath = sprintf("/ovf:Envelope/ovf:References/ovf:File[\@ovf:id='%s']/\@ovf:href", $fileref); + my $filepath = $xpc->findvalue($xpath_find_filepath); + if (!$filepath) { + warn "invalid file reference $fileref, skipping\n"; + next; + } + print "file path: $filepath\n" if $debug; + my $original_filepath = $filepath; + ($filepath) = $filepath =~ m|^(${PVE::Storage::SAFE_CHAR_CLASS_RE}+)$|; # untaint & check no sub/parent dirs + die "referenced path '$original_filepath' is invalid\n" if !$filepath || $filepath eq "." || $filepath eq ".."; + # resolve symlinks and relative path components # and die if the diskimage is not somewhere under the $ovf path - my $ovf_dir = realpath(dirname(File::Spec->rel2abs($ovf))); - my $backing_file_path = realpath(join ('/', $ovf_dir, $filepath)); + my $ovf_dir = realpath(dirname(File::Spec->rel2abs($ovf))) + or die "could not get absolute path of $ovf: $!\n"; + my $backing_file_path = realpath(join ('/', $ovf_dir, $filepath)) + or die "could not get absolute path of $filepath: $!\n"; if ($backing_file_path !~ /^\Q${ovf_dir}\E/) { die "error parsing $filepath, are you using a symlink ?\n"; } + ($backing_file_path) = $backing_file_path =~ m|^(/.*)|; # untaint + if (!-e $backing_file_path && !$isOva) { die "error parsing $filepath, file seems not to exist at $backing_file_path\n"; } - ($backing_file_path) = $backing_file_path =~ m|^(/.*)|; # untaint - ($filepath) = $filepath =~ m|^(${PVE::Storage::SAFE_CHAR_CLASS_RE}+)$|; # untaint & check no sub/parent dirs - die "invalid path\n" if !$filepath; - if (!$isOva) { my $size = PVE::Storage::file_size_info($backing_file_path); die "error parsing $backing_file_path, cannot determine file size\n" -- 2.39.5 _______________________________________________ pve-devel mailing list pve-devel@lists.proxmox.com https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel