Maciej/Laszlo, Sorry I missed this patch. It looks good with me.
Reviewed-by: Siyuan Fu <siyuan...@intel.com> > -----Original Message----- > From: devel@edk2.groups.io <devel@edk2.groups.io> On Behalf Of Laszlo Ersek > Sent: 2020年3月25日 19:36 > To: Wu, Jiaxin <jiaxin...@intel.com>; Fu, Siyuan <siyuan...@intel.com> > Cc: devel@edk2.groups.io; maciej.rab...@linux.intel.com > Subject: Re: [edk2-devel] [PATCH v1] NetworkPkg/Ip6Dxe: Improve Neightbor > Discovery message validation (CVE-2019-14559) > > Jiaxin, Siyuan, > > On 03/02/20 13:38, Maciej Rabeda wrote: > > REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2174 > > > > Problem has been identified with Ip6ProcessRouterAdvertise() when > > Router Advertise packet contains options with malicious/invalid > > 'Length' field. This can lead to platform entering infinite loop > > when processing options from that packet. > > > > Cc: Jiaxin Wu <jiaxin...@intel.com> > > Cc: Siyuan Fu <siyuan...@intel.com> > > Signed-off-by: Maciej Rabeda <maciej.rab...@linux.intel.com> > > --- > > NetworkPkg/Ip6Dxe/Ip6Nd.c | 44 +++++++++------ > > NetworkPkg/Ip6Dxe/Ip6Nd.h | 13 +++++ > > NetworkPkg/Ip6Dxe/Ip6Option.c | 57 +++++++++++++++----- > > 3 files changed, 83 insertions(+), 31 deletions(-) > > can you please review this patch? It has spent 3+ weeks on the list. > > Thanks, > Laszlo > > > diff --git a/NetworkPkg/Ip6Dxe/Ip6Nd.c b/NetworkPkg/Ip6Dxe/Ip6Nd.c > > index 4288ef02dd46..fd7f60b2f92c 100644 > > --- a/NetworkPkg/Ip6Dxe/Ip6Nd.c > > +++ b/NetworkPkg/Ip6Dxe/Ip6Nd.c > > @@ -1927,7 +1927,7 @@ Ip6ProcessRouterAdvertise ( > > UINT32 ReachableTime; > > UINT32 RetransTimer; > > UINT16 RouterLifetime; > > - UINT16 Offset; > > + UINT32 Offset; > > UINT8 Type; > > UINT8 Length; > > IP6_ETHER_ADDR_OPTION LinkLayerOption; > > @@ -2094,10 +2094,11 @@ Ip6ProcessRouterAdvertise ( > > // > > // The only defined options that may appear are the Source > > // Link-Layer Address, Prefix information and MTU options. > > - // All included options have a length that is greater than zero. > > + // All included options have a length that is greater than zero and > > + // fit within the input packet. > > // > > Offset = 16; > > - while (Offset < Head->PayloadLength) { > > + while (Offset < (UINT32) Head->PayloadLength) { > > NetbufCopy (Packet, Offset, sizeof (UINT8), &Type); > > switch (Type) { > > case Ip6OptionEtherSource: > > @@ -2105,9 +2106,12 @@ Ip6ProcessRouterAdvertise ( > > // Update the neighbor cache > > // > > NetbufCopy (Packet, Offset, sizeof (IP6_ETHER_ADDR_OPTION), (UINT8 *) > &LinkLayerOption); > > - if (LinkLayerOption.Length <= 0) { > > - goto Exit; > > - } > > + > > + // > > + // Option size validity ensured by Ip6IsNDOptionValid(). > > + // > > + ASSERT (LinkLayerOption.Length != 0); > > + ASSERT (Offset + (UINT32) LinkLayerOption.Length * 8 >= (UINT32) > > Head- > >PayloadLength); > > > > ZeroMem (&LinkLayerAddress, sizeof (EFI_MAC_ADDRESS)); > > CopyMem (&LinkLayerAddress, LinkLayerOption.EtherAddr, 6); > > @@ -2151,13 +2155,17 @@ Ip6ProcessRouterAdvertise ( > > } > > } > > > > - Offset = (UINT16) (Offset + (UINT16) LinkLayerOption.Length * 8); > > + Offset += (UINT32) LinkLayerOption.Length * 8; > > break; > > case Ip6OptionPrefixInfo: > > NetbufCopy (Packet, Offset, sizeof (IP6_PREFIX_INFO_OPTION), (UINT8 > > *) > &PrefixOption); > > - if (PrefixOption.Length != 4) { > > - goto Exit; > > - } > > + > > + // > > + // Option size validity ensured by Ip6IsNDOptionValid(). > > + // > > + ASSERT (PrefixOption.Length == 4); > > + ASSERT (Offset + (UINT32) PrefixOption.Length * 8 >= (UINT32) Head- > >PayloadLength); > > + > > PrefixOption.ValidLifetime = NTOHL (PrefixOption.ValidLifetime); > > PrefixOption.PreferredLifetime = NTOHL > > (PrefixOption.PreferredLifetime); > > > > @@ -2321,9 +2329,12 @@ Ip6ProcessRouterAdvertise ( > > break; > > case Ip6OptionMtu: > > NetbufCopy (Packet, Offset, sizeof (IP6_MTU_OPTION), (UINT8 *) > &MTUOption); > > - if (MTUOption.Length != 1) { > > - goto Exit; > > - } > > + > > + // > > + // Option size validity ensured by Ip6IsNDOptionValid(). > > + // > > + ASSERT (MTUOption.Length == 1); > > + ASSERT (Offset + (UINT32) MTUOption.Length * 8 >= (UINT32) Head- > >PayloadLength); > > > > // > > // Use IPv6 minimum link MTU 1280 bytes as the maximum packet size in > order > > @@ -2338,11 +2349,10 @@ Ip6ProcessRouterAdvertise ( > > // Silently ignore unrecognized options > > // > > NetbufCopy (Packet, Offset + sizeof (UINT8), sizeof (UINT8), > > &Length); > > - if (Length <= 0) { > > - goto Exit; > > - } > > > > - Offset = (UINT16) (Offset + (UINT16) Length * 8); > > + ASSERT (Length != 0); > > + > > + Offset += (UINT32) Length * 8; > > break; > > } > > } > > diff --git a/NetworkPkg/Ip6Dxe/Ip6Nd.h b/NetworkPkg/Ip6Dxe/Ip6Nd.h > > index 560dfa343782..5f1bd6fb922a 100644 > > --- a/NetworkPkg/Ip6Dxe/Ip6Nd.h > > +++ b/NetworkPkg/Ip6Dxe/Ip6Nd.h > > @@ -56,12 +56,21 @@ VOID > > VOID *Context > > ); > > > > +typedef struct _IP6_OPTION_HEADER { > > + UINT8 Type; > > + UINT8 Length; > > +} IP6_OPTION_HEADER; > > + > > +STATIC_ASSERT (sizeof (IP6_OPTION_HEADER) == 2, "IP6_OPTION_HEADER is > expected to be exactly 2 bytes long."); > > + > > typedef struct _IP6_ETHE_ADDR_OPTION { > > UINT8 Type; > > UINT8 Length; > > UINT8 EtherAddr[6]; > > } IP6_ETHER_ADDR_OPTION; > > > > +STATIC_ASSERT (sizeof (IP6_ETHER_ADDR_OPTION) == 8, > "IP6_ETHER_ADDR_OPTION is expected to be exactly 8 bytes long."); > > + > > typedef struct _IP6_MTU_OPTION { > > UINT8 Type; > > UINT8 Length; > > @@ -69,6 +78,8 @@ typedef struct _IP6_MTU_OPTION { > > UINT32 Mtu; > > } IP6_MTU_OPTION; > > > > +STATIC_ASSERT (sizeof (IP6_MTU_OPTION) == 8, "IP6_MTU_OPTION is > expected to be exactly 8 bytes long."); > > + > > typedef struct _IP6_PREFIX_INFO_OPTION { > > UINT8 Type; > > UINT8 Length; > > @@ -80,6 +91,8 @@ typedef struct _IP6_PREFIX_INFO_OPTION { > > EFI_IPv6_ADDRESS Prefix; > > } IP6_PREFIX_INFO_OPTION; > > > > +STATIC_ASSERT (sizeof (IP6_PREFIX_INFO_OPTION) == 32, > "IP6_PREFIX_INFO_OPTION is expected to be exactly 32 bytes long."); > > + > > typedef > > VOID > > (*IP6_DAD_CALLBACK) ( > > diff --git a/NetworkPkg/Ip6Dxe/Ip6Option.c > b/NetworkPkg/Ip6Dxe/Ip6Option.c > > index 4d92a852dc86..6b4b029d1479 100644 > > --- a/NetworkPkg/Ip6Dxe/Ip6Option.c > > +++ b/NetworkPkg/Ip6Dxe/Ip6Option.c > > @@ -129,45 +129,74 @@ Ip6IsNDOptionValid ( > > IN UINT16 OptionLen > > ) > > { > > - UINT16 Offset; > > - UINT8 OptionType; > > + UINT32 Offset; > > UINT16 Length; > > + IP6_OPTION_HEADER *OptionHeader; > > + > > + if (Option == NULL) { > > + ASSERT (Option != NULL); > > + return FALSE; > > + } > > > > Offset = 0; > > > > - while (Offset < OptionLen) { > > - OptionType = *(Option + Offset); > > - Length = (UINT16) (*(Option + Offset + 1) * 8); > > + // > > + // RFC 4861 states that Neighbor Discovery packet can contain zero or > > more > > + // options. Start processing the options if at least Type + Length fields > > + // fit within the input buffer. > > + // > > + while (Offset + sizeof (IP6_OPTION_HEADER) - 1 < OptionLen) { > > + OptionHeader = (IP6_OPTION_HEADER*) (Option + Offset); > > + Length = (UINT16) OptionHeader->Length * 8; > > > > - switch (OptionType) { > > + switch (OptionHeader->Type) { > > case Ip6OptionPrefixInfo: > > if (Length != 32) { > > return FALSE; > > } > > - > > break; > > > > case Ip6OptionMtu: > > if (Length != 8) { > > return FALSE; > > } > > - > > break; > > > > default: > > - // > > - // Check the length of Ip6OptionEtherSource, Ip6OptionEtherTarget, > > and > > - // Ip6OptionRedirected here. For unrecognized options, silently > > ignore > > - // and continue processing the message. > > - // > > + // RFC 4861 states that Length field cannot be 0. > > if (Length == 0) { > > return FALSE; > > } > > + break; > > + } > > + > > + // > > + // Check whether recognized options are within the input buffer's > > scope. > > + // > > + switch (OptionHeader->Type) { > > + case Ip6OptionEtherSource: > > + case Ip6OptionEtherTarget: > > + case Ip6OptionPrefixInfo: > > + case Ip6OptionRedirected: > > + case Ip6OptionMtu: > > + if (Offset + Length > (UINT32) OptionLen) { > > + return FALSE; > > + } > > + break; > > > > + default: > > + // > > + // Unrecognized options can be either valid (but unused) or invalid > > + // (garbage in between or right after valid options). Silently > > ignore. > > + // > > break; > > } > > > > - Offset = (UINT16) (Offset + Length); > > + // > > + // Advance to the next option. > > + // Length already considers option header's Type + Length. > > + // > > + Offset += Length; > > } > > > > return TRUE; > > > > > -=-=-=-=-=-=-=-=-=-=-=- Groups.io Links: You receive all messages sent to this group. View/Reply Online (#56347): https://edk2.groups.io/g/devel/message/56347 Mute This Topic: https://groups.io/mt/71673126/21656 Group Owner: devel+ow...@edk2.groups.io Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com] -=-=-=-=-=-=-=-=-=-=-=-
