* Re: [Linux-cifsd-devel] [PATCH] cifsd: Do not use 0 as TreeID [not found] ` <CAKYAXd_64YRcho0Qnq+ccezVL7Tu2_9Jjb8PM+GDujZ9h8x6xw@mail.gmail.com> @ 2021-05-15 14:27 ` Stefan Metzmacher 2021-05-15 14:48 ` Namjae Jeon 0 siblings, 1 reply; 4+ messages in thread From: Stefan Metzmacher @ 2021-05-15 14:27 UTC (permalink / raw) To: Namjae Jeon; +Cc: Marios Makassikis, linux-cifsd-devel, linux-cifs [-- Attachment #1.1: Type: text/plain, Size: 5164 bytes --] Am 15.05.21 um 16:10 schrieb Namjae Jeon: > 2021-05-15 17:57 GMT+09:00, Stefan Metzmacher <metze@samba.org>: >> >> Am 15.05.21 um 07:18 schrieb Namjae Jeon: >>> 2021-05-14 22:11 GMT+09:00, Stefan Metzmacher via Linux-cifsd-devel >>> <linux-cifsd-devel@lists.sourceforge.net>: >>>> >>>> Am 14.05.21 um 14:52 schrieb Marios Makassikis: >>>>> Returning TreeID=0 is valid behaviour according to [MS-SMB2] 2.2.1.2: >>>>> >>>>> TreeId (4 bytes): Uniquely identifies the tree connect for the >>>>> command. >>>>> This MUST be 0 for the SMB2 TREE_CONNECT Request. The TreeId can be >>>>> any unsigned 32-bit integer that is received from a previous >>>>> SMB2 TREE_CONNECT Response. TreeId SHOULD be set to 0 for the >>>>> following commands: >>>>> [...] >>>>> >>>>> However, some client implementations reject it as invalid. Windows 7/10 >>>>> assigns ids starting from 1, and samba4 returns a random uint32_t >>>>> which suggests there may be other clients that consider it is >>>>> invalid behaviour. >>>>> >>>>> While here, simplify ksmbd_acquire_smb2_tid. 0xFFFF is a reserved value >>>>> for CIFS/SMB1: >>>>> [MS-CIFS] 2.2.4.50.2 >>>>> >>>>> TID (2 bytes): The newly generated Tree ID, used in subsequent CIFS >>>>> client requests to refer to a resource relative to the >>>>> SMB_Data.Bytes.Path specified in the request. Most access to the >>>>> server requires a valid TID, whether the resource is password >>>>> protected or not. The value 0xFFFF is reserved; the server MUST NOT >>>>> return a TID value of 0xFFFF. >>>>> >>>>> Signed-off-by: Marios Makassikis <mmakassikis@freebox.fr> >>>>> --- >>>>> Example library that treats zero TreeID as invalid: >>>>> >>>>> https://github.com/AgNO3/jcifs-ng/blob/master/src/main/java/jcifs/internal/smb2/tree/Smb2TreeConnectResponse.java#L201 >>>>> >>>>> mgmt/ksmbd_ida.c | 9 ++------- >>>>> 1 file changed, 2 insertions(+), 7 deletions(-) >>>>> >>>>> diff --git a/mgmt/ksmbd_ida.c b/mgmt/ksmbd_ida.c >>>>> index 7eb6476..34e0d2e 100644 >>>>> --- a/mgmt/ksmbd_ida.c >>>>> +++ b/mgmt/ksmbd_ida.c >>>>> @@ -13,19 +13,14 @@ static inline int __acquire_id(struct ida *ida, int >>>>> from, int to) >>>>> #ifdef CONFIG_SMB_INSECURE_SERVER >>>>> int ksmbd_acquire_smb1_tid(struct ida *ida) >>>>> { >>>>> - return __acquire_id(ida, 0, 0xFFFF); >>>>> + return __acquire_id(ida, 1, 0xFFFF); >>>>> } >>>>> #endif >>>>> >>>>> int ksmbd_acquire_smb2_tid(struct ida *ida) >>>>> { >>>>> - int id; >>>>> + return __acquire_id(ida, 1, 0); >>>> >>>> I think that should be __acquire_id(ida, 1, 0xFFFFFFFF) (or a lower >>>> constraint) >>>> >>>> 0xFFFFFFFF is used for compound requests to inherit the tree id from the >>>> previous request. >>> Where is it defined in the specification ? As I know, >>> SMB2_FLAGS_RELATED_OPERATIONS flags in smb header indicate inherit >>> tree id in previous request. >> >> [MS-SMB2] 3.2.4.1.4 Sending Compounded Requests >> >> ... >> >> The client MUST construct the subsequent request as it would do normally. >> For any subsequent >> requests the client MUST set SMB2_FLAGS_RELATED_OPERATIONS in the Flags >> field of the SMB2 >> header to indicate that it is using the SessionId, TreeId, and FileId >> supplied in the previous >> request (or generated by the server in processing that request). For an >> operation compounded >> with an SMB2 CREATE request, the FileId field SHOULD be set to { >> 0xFFFFFFFFFFFFFFFF, >> 0xFFFFFFFFFFFFFFFF }. >> >> This only explicitly talks about FileId and I'm not any client would do >> that, but in theory it should be possible to >> compound, the 2nd session setup request (of an anonymous authentication) >> with a tree connect request >> and an open. >> >> Which means it's the safest behavior for a server to avoid 0 and all F as >> valid id, >> there're still enough ids to use.... >> >> It also makes sure that we don't end up with very confusing network >> captures. > Okay, I have checked cifs client code like the following. > > if (request_type & CHAINED_REQUEST) { > if (!(request_type & END_OF_CHAIN)) { > /* next 8-byte aligned request */ > *total_len = DIV_ROUND_UP(*total_len, 8) * 8; > shdr->NextCommand = cpu_to_le32(*total_len); > } else /* END_OF_CHAIN */ > shdr->NextCommand = 0; > if (request_type & RELATED_REQUEST) { > shdr->Flags |= SMB2_FLAGS_RELATED_OPERATIONS; > /* > * Related requests use info from previous read request > * in chain. > */ > shdr->SessionId = 0xFFFFFFFF; > shdr->TreeId = 0xFFFFFFFF; > req->PersistentFileId = 0xFFFFFFFF; > req->VolatileFileId = 0xFFFFFFFF; > } Which seems actually wrong and should be 0xFFFFFFFFFFFFFFFF for all but TreeId... metze [-- Attachment #2: OpenPGP digital signature --] [-- Type: application/pgp-signature, Size: 833 bytes --] ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Linux-cifsd-devel] [PATCH] cifsd: Do not use 0 as TreeID 2021-05-15 14:27 ` [Linux-cifsd-devel] [PATCH] cifsd: Do not use 0 as TreeID Stefan Metzmacher @ 2021-05-15 14:48 ` Namjae Jeon 2021-05-15 14:59 ` Steve French 0 siblings, 1 reply; 4+ messages in thread From: Namjae Jeon @ 2021-05-15 14:48 UTC (permalink / raw) To: Stefan Metzmacher; +Cc: Marios Makassikis, linux-cifsd-devel, linux-cifs 2021-05-15 23:27 GMT+09:00, Stefan Metzmacher <metze@samba.org>: > Am 15.05.21 um 16:10 schrieb Namjae Jeon: >> 2021-05-15 17:57 GMT+09:00, Stefan Metzmacher <metze@samba.org>: >>> >>> Am 15.05.21 um 07:18 schrieb Namjae Jeon: >>>> 2021-05-14 22:11 GMT+09:00, Stefan Metzmacher via Linux-cifsd-devel >>>> <linux-cifsd-devel@lists.sourceforge.net>: >>>>> >>>>> Am 14.05.21 um 14:52 schrieb Marios Makassikis: >>>>>> Returning TreeID=0 is valid behaviour according to [MS-SMB2] 2.2.1.2: >>>>>> >>>>>> TreeId (4 bytes): Uniquely identifies the tree connect for the >>>>>> command. >>>>>> This MUST be 0 for the SMB2 TREE_CONNECT Request. The TreeId can be >>>>>> any unsigned 32-bit integer that is received from a previous >>>>>> SMB2 TREE_CONNECT Response. TreeId SHOULD be set to 0 for the >>>>>> following commands: >>>>>> [...] >>>>>> >>>>>> However, some client implementations reject it as invalid. Windows >>>>>> 7/10 >>>>>> assigns ids starting from 1, and samba4 returns a random uint32_t >>>>>> which suggests there may be other clients that consider it is >>>>>> invalid behaviour. >>>>>> >>>>>> While here, simplify ksmbd_acquire_smb2_tid. 0xFFFF is a reserved >>>>>> value >>>>>> for CIFS/SMB1: >>>>>> [MS-CIFS] 2.2.4.50.2 >>>>>> >>>>>> TID (2 bytes): The newly generated Tree ID, used in subsequent CIFS >>>>>> client requests to refer to a resource relative to the >>>>>> SMB_Data.Bytes.Path specified in the request. Most access to the >>>>>> server requires a valid TID, whether the resource is password >>>>>> protected or not. The value 0xFFFF is reserved; the server MUST NOT >>>>>> return a TID value of 0xFFFF. >>>>>> >>>>>> Signed-off-by: Marios Makassikis <mmakassikis@freebox.fr> >>>>>> --- >>>>>> Example library that treats zero TreeID as invalid: >>>>>> >>>>>> https://github.com/AgNO3/jcifs-ng/blob/master/src/main/java/jcifs/internal/smb2/tree/Smb2TreeConnectResponse.java#L201 >>>>>> >>>>>> mgmt/ksmbd_ida.c | 9 ++------- >>>>>> 1 file changed, 2 insertions(+), 7 deletions(-) >>>>>> >>>>>> diff --git a/mgmt/ksmbd_ida.c b/mgmt/ksmbd_ida.c >>>>>> index 7eb6476..34e0d2e 100644 >>>>>> --- a/mgmt/ksmbd_ida.c >>>>>> +++ b/mgmt/ksmbd_ida.c >>>>>> @@ -13,19 +13,14 @@ static inline int __acquire_id(struct ida *ida, >>>>>> int >>>>>> from, int to) >>>>>> #ifdef CONFIG_SMB_INSECURE_SERVER >>>>>> int ksmbd_acquire_smb1_tid(struct ida *ida) >>>>>> { >>>>>> - return __acquire_id(ida, 0, 0xFFFF); >>>>>> + return __acquire_id(ida, 1, 0xFFFF); >>>>>> } >>>>>> #endif >>>>>> >>>>>> int ksmbd_acquire_smb2_tid(struct ida *ida) >>>>>> { >>>>>> - int id; >>>>>> + return __acquire_id(ida, 1, 0); >>>>> >>>>> I think that should be __acquire_id(ida, 1, 0xFFFFFFFF) (or a lower >>>>> constraint) >>>>> >>>>> 0xFFFFFFFF is used for compound requests to inherit the tree id from >>>>> the >>>>> previous request. >>>> Where is it defined in the specification ? As I know, >>>> SMB2_FLAGS_RELATED_OPERATIONS flags in smb header indicate inherit >>>> tree id in previous request. >>> >>> [MS-SMB2] 3.2.4.1.4 Sending Compounded Requests >>> >>> ... >>> >>> The client MUST construct the subsequent request as it would do >>> normally. >>> For any subsequent >>> requests the client MUST set SMB2_FLAGS_RELATED_OPERATIONS in the >>> Flags >>> field of the SMB2 >>> header to indicate that it is using the SessionId, TreeId, and FileId >>> supplied in the previous >>> request (or generated by the server in processing that request). For >>> an >>> operation compounded >>> with an SMB2 CREATE request, the FileId field SHOULD be set to { >>> 0xFFFFFFFFFFFFFFFF, >>> 0xFFFFFFFFFFFFFFFF }. >>> >>> This only explicitly talks about FileId and I'm not any client would do >>> that, but in theory it should be possible to >>> compound, the 2nd session setup request (of an anonymous authentication) >>> with a tree connect request >>> and an open. >>> >>> Which means it's the safest behavior for a server to avoid 0 and all F >>> as >>> valid id, >>> there're still enough ids to use.... >>> >>> It also makes sure that we don't end up with very confusing network >>> captures. >> Okay, I have checked cifs client code like the following. >> >> if (request_type & CHAINED_REQUEST) { >> if (!(request_type & END_OF_CHAIN)) { >> /* next 8-byte aligned request */ >> *total_len = DIV_ROUND_UP(*total_len, 8) * 8; >> shdr->NextCommand = cpu_to_le32(*total_len); >> } else /* END_OF_CHAIN */ >> shdr->NextCommand = 0; >> if (request_type & RELATED_REQUEST) { >> shdr->Flags |= SMB2_FLAGS_RELATED_OPERATIONS; >> /* >> * Related requests use info from previous read >> request >> * in chain. >> */ >> shdr->SessionId = 0xFFFFFFFF; >> shdr->TreeId = 0xFFFFFFFF; >> req->PersistentFileId = 0xFFFFFFFF; >> req->VolatileFileId = 0xFFFFFFFF; >> } > > Which seems actually wrong and should be 0xFFFFFFFFFFFFFFFF for all but > TreeId... Oh that's right... > > metze > > > ^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [Linux-cifsd-devel] [PATCH] cifsd: Do not use 0 as TreeID 2021-05-15 14:48 ` Namjae Jeon @ 2021-05-15 14:59 ` Steve French 2021-05-19 12:02 ` Shyam Prasad N 0 siblings, 1 reply; 4+ messages in thread From: Steve French @ 2021-05-15 14:59 UTC (permalink / raw) To: CIFS Cc: Stefan Metzmacher, COMMON INTERNET FILE SYSTEM SERVER, Pavel Shilovsky, Namjae Jeon [-- Attachment #1: Type: text/plain, Size: 6190 bytes --] Patch attached to fix the problem with incorrect FileIDs for compounded requests (on the client) - the problem pointed out by Metze See MS-SMB2 3.2.4.1.4 "For an operation compounded with an SMB2 CREATE request, the FileId field SHOULD be set to { 0xFFFFFFFFFFFFFFFF, 0xFFFFFFFFFFFFFFFF }. On Sat, May 15, 2021 at 9:49 AM Namjae Jeon <linkinjeon@kernel.org> wrote: > > 2021-05-15 23:27 GMT+09:00, Stefan Metzmacher <metze@samba.org>: > > Am 15.05.21 um 16:10 schrieb Namjae Jeon: > >> 2021-05-15 17:57 GMT+09:00, Stefan Metzmacher <metze@samba.org>: > >>> > >>> Am 15.05.21 um 07:18 schrieb Namjae Jeon: > >>>> 2021-05-14 22:11 GMT+09:00, Stefan Metzmacher via Linux-cifsd-devel > >>>> <linux-cifsd-devel@lists.sourceforge.net>: > >>>>> > >>>>> Am 14.05.21 um 14:52 schrieb Marios Makassikis: > >>>>>> Returning TreeID=0 is valid behaviour according to [MS-SMB2] 2.2.1.2: > >>>>>> > >>>>>> TreeId (4 bytes): Uniquely identifies the tree connect for the > >>>>>> command. > >>>>>> This MUST be 0 for the SMB2 TREE_CONNECT Request. The TreeId can be > >>>>>> any unsigned 32-bit integer that is received from a previous > >>>>>> SMB2 TREE_CONNECT Response. TreeId SHOULD be set to 0 for the > >>>>>> following commands: > >>>>>> [...] > >>>>>> > >>>>>> However, some client implementations reject it as invalid. Windows > >>>>>> 7/10 > >>>>>> assigns ids starting from 1, and samba4 returns a random uint32_t > >>>>>> which suggests there may be other clients that consider it is > >>>>>> invalid behaviour. > >>>>>> > >>>>>> While here, simplify ksmbd_acquire_smb2_tid. 0xFFFF is a reserved > >>>>>> value > >>>>>> for CIFS/SMB1: > >>>>>> [MS-CIFS] 2.2.4.50.2 > >>>>>> > >>>>>> TID (2 bytes): The newly generated Tree ID, used in subsequent CIFS > >>>>>> client requests to refer to a resource relative to the > >>>>>> SMB_Data.Bytes.Path specified in the request. Most access to the > >>>>>> server requires a valid TID, whether the resource is password > >>>>>> protected or not. The value 0xFFFF is reserved; the server MUST NOT > >>>>>> return a TID value of 0xFFFF. > >>>>>> > >>>>>> Signed-off-by: Marios Makassikis <mmakassikis@freebox.fr> > >>>>>> --- > >>>>>> Example library that treats zero TreeID as invalid: > >>>>>> > >>>>>> https://github.com/AgNO3/jcifs-ng/blob/master/src/main/java/jcifs/internal/smb2/tree/Smb2TreeConnectResponse.java#L201 > >>>>>> > >>>>>> mgmt/ksmbd_ida.c | 9 ++------- > >>>>>> 1 file changed, 2 insertions(+), 7 deletions(-) > >>>>>> > >>>>>> diff --git a/mgmt/ksmbd_ida.c b/mgmt/ksmbd_ida.c > >>>>>> index 7eb6476..34e0d2e 100644 > >>>>>> --- a/mgmt/ksmbd_ida.c > >>>>>> +++ b/mgmt/ksmbd_ida.c > >>>>>> @@ -13,19 +13,14 @@ static inline int __acquire_id(struct ida *ida, > >>>>>> int > >>>>>> from, int to) > >>>>>> #ifdef CONFIG_SMB_INSECURE_SERVER > >>>>>> int ksmbd_acquire_smb1_tid(struct ida *ida) > >>>>>> { > >>>>>> - return __acquire_id(ida, 0, 0xFFFF); > >>>>>> + return __acquire_id(ida, 1, 0xFFFF); > >>>>>> } > >>>>>> #endif > >>>>>> > >>>>>> int ksmbd_acquire_smb2_tid(struct ida *ida) > >>>>>> { > >>>>>> - int id; > >>>>>> + return __acquire_id(ida, 1, 0); > >>>>> > >>>>> I think that should be __acquire_id(ida, 1, 0xFFFFFFFF) (or a lower > >>>>> constraint) > >>>>> > >>>>> 0xFFFFFFFF is used for compound requests to inherit the tree id from > >>>>> the > >>>>> previous request. > >>>> Where is it defined in the specification ? As I know, > >>>> SMB2_FLAGS_RELATED_OPERATIONS flags in smb header indicate inherit > >>>> tree id in previous request. > >>> > >>> [MS-SMB2] 3.2.4.1.4 Sending Compounded Requests > >>> > >>> ... > >>> > >>> The client MUST construct the subsequent request as it would do > >>> normally. > >>> For any subsequent > >>> requests the client MUST set SMB2_FLAGS_RELATED_OPERATIONS in the > >>> Flags > >>> field of the SMB2 > >>> header to indicate that it is using the SessionId, TreeId, and FileId > >>> supplied in the previous > >>> request (or generated by the server in processing that request). For > >>> an > >>> operation compounded > >>> with an SMB2 CREATE request, the FileId field SHOULD be set to { > >>> 0xFFFFFFFFFFFFFFFF, > >>> 0xFFFFFFFFFFFFFFFF }. > >>> > >>> This only explicitly talks about FileId and I'm not any client would do > >>> that, but in theory it should be possible to > >>> compound, the 2nd session setup request (of an anonymous authentication) > >>> with a tree connect request > >>> and an open. > >>> > >>> Which means it's the safest behavior for a server to avoid 0 and all F > >>> as > >>> valid id, > >>> there're still enough ids to use.... > >>> > >>> It also makes sure that we don't end up with very confusing network > >>> captures. > >> Okay, I have checked cifs client code like the following. > >> > >> if (request_type & CHAINED_REQUEST) { > >> if (!(request_type & END_OF_CHAIN)) { > >> /* next 8-byte aligned request */ > >> *total_len = DIV_ROUND_UP(*total_len, 8) * 8; > >> shdr->NextCommand = cpu_to_le32(*total_len); > >> } else /* END_OF_CHAIN */ > >> shdr->NextCommand = 0; > >> if (request_type & RELATED_REQUEST) { > >> shdr->Flags |= SMB2_FLAGS_RELATED_OPERATIONS; > >> /* > >> * Related requests use info from previous read > >> request > >> * in chain. > >> */ > >> shdr->SessionId = 0xFFFFFFFF; > >> shdr->TreeId = 0xFFFFFFFF; > >> req->PersistentFileId = 0xFFFFFFFF; > >> req->VolatileFileId = 0xFFFFFFFF; > >> } > > > > Which seems actually wrong and should be 0xFFFFFFFFFFFFFFFF for all but > > TreeId... > Oh that's right... > > > > metze > > > > > > > > > _______________________________________________ > Linux-cifsd-devel mailing list > Linux-cifsd-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/linux-cifsd-devel -- Thanks, Steve [-- Attachment #2: 0001-SMB3-incorrect-file-id-in-requests-compounded-with-o.patch --] [-- Type: text/x-patch, Size: 1216 bytes --] From eb652867e0d1ff6062f4b0e504cd43013c15be58 Mon Sep 17 00:00:00 2001 From: Steve French <stfrench@microsoft.com> Date: Sat, 15 May 2021 09:52:22 -0500 Subject: [PATCH] SMB3: incorrect file id in requests compounded with open See MS-SMB2 3.2.4.1.4, file ids in compounded requests should be set to 0xFFFFFFFFFFFFFFFF (we were treating it as u32 not u64 and setting it incorrectly). Signed-off-by: Steve French <stfrench@microsoft.com> Reported-by: Stefan Metzmacher <metze@samba.org> --- fs/cifs/smb2pdu.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index a8bf43184773..9f24eb88297a 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -3900,10 +3900,10 @@ smb2_new_read_req(void **buf, unsigned int *total_len, * Related requests use info from previous read request * in chain. */ - shdr->SessionId = 0xFFFFFFFF; + shdr->SessionId = 0xFFFFFFFFFFFFFFFF; shdr->TreeId = 0xFFFFFFFF; - req->PersistentFileId = 0xFFFFFFFF; - req->VolatileFileId = 0xFFFFFFFF; + req->PersistentFileId = 0xFFFFFFFFFFFFFFFF; + req->VolatileFileId = 0xFFFFFFFFFFFFFFFF; } } if (remaining_bytes > io_parms->length) -- 2.30.2 ^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [Linux-cifsd-devel] [PATCH] cifsd: Do not use 0 as TreeID 2021-05-15 14:59 ` Steve French @ 2021-05-19 12:02 ` Shyam Prasad N 0 siblings, 0 replies; 4+ messages in thread From: Shyam Prasad N @ 2021-05-19 12:02 UTC (permalink / raw) To: Steve French Cc: CIFS, Stefan Metzmacher, COMMON INTERNET FILE SYSTEM SERVER, Pavel Shilovsky, Namjae Jeon The fix looks good to me. Reviewed-by: Shyam Prasad N <sprasad@microsoft.com> On Sun, May 16, 2021 at 3:48 AM Steve French <smfrench@gmail.com> wrote: > > Patch attached to fix the problem with incorrect FileIDs for > compounded requests (on the client) - the problem pointed out by Metze > > See MS-SMB2 3.2.4.1.4 > > "For an operation compounded with an SMB2 CREATE request, the FileId > field SHOULD be set to { 0xFFFFFFFFFFFFFFFF, > 0xFFFFFFFFFFFFFFFF }. > > On Sat, May 15, 2021 at 9:49 AM Namjae Jeon <linkinjeon@kernel.org> wrote: > > > > 2021-05-15 23:27 GMT+09:00, Stefan Metzmacher <metze@samba.org>: > > > Am 15.05.21 um 16:10 schrieb Namjae Jeon: > > >> 2021-05-15 17:57 GMT+09:00, Stefan Metzmacher <metze@samba.org>: > > >>> > > >>> Am 15.05.21 um 07:18 schrieb Namjae Jeon: > > >>>> 2021-05-14 22:11 GMT+09:00, Stefan Metzmacher via Linux-cifsd-devel > > >>>> <linux-cifsd-devel@lists.sourceforge.net>: > > >>>>> > > >>>>> Am 14.05.21 um 14:52 schrieb Marios Makassikis: > > >>>>>> Returning TreeID=0 is valid behaviour according to [MS-SMB2] 2.2.1.2: > > >>>>>> > > >>>>>> TreeId (4 bytes): Uniquely identifies the tree connect for the > > >>>>>> command. > > >>>>>> This MUST be 0 for the SMB2 TREE_CONNECT Request. The TreeId can be > > >>>>>> any unsigned 32-bit integer that is received from a previous > > >>>>>> SMB2 TREE_CONNECT Response. TreeId SHOULD be set to 0 for the > > >>>>>> following commands: > > >>>>>> [...] > > >>>>>> > > >>>>>> However, some client implementations reject it as invalid. Windows > > >>>>>> 7/10 > > >>>>>> assigns ids starting from 1, and samba4 returns a random uint32_t > > >>>>>> which suggests there may be other clients that consider it is > > >>>>>> invalid behaviour. > > >>>>>> > > >>>>>> While here, simplify ksmbd_acquire_smb2_tid. 0xFFFF is a reserved > > >>>>>> value > > >>>>>> for CIFS/SMB1: > > >>>>>> [MS-CIFS] 2.2.4.50.2 > > >>>>>> > > >>>>>> TID (2 bytes): The newly generated Tree ID, used in subsequent CIFS > > >>>>>> client requests to refer to a resource relative to the > > >>>>>> SMB_Data.Bytes.Path specified in the request. Most access to the > > >>>>>> server requires a valid TID, whether the resource is password > > >>>>>> protected or not. The value 0xFFFF is reserved; the server MUST NOT > > >>>>>> return a TID value of 0xFFFF. > > >>>>>> > > >>>>>> Signed-off-by: Marios Makassikis <mmakassikis@freebox.fr> > > >>>>>> --- > > >>>>>> Example library that treats zero TreeID as invalid: > > >>>>>> > > >>>>>> https://github.com/AgNO3/jcifs-ng/blob/master/src/main/java/jcifs/internal/smb2/tree/Smb2TreeConnectResponse.java#L201 > > >>>>>> > > >>>>>> mgmt/ksmbd_ida.c | 9 ++------- > > >>>>>> 1 file changed, 2 insertions(+), 7 deletions(-) > > >>>>>> > > >>>>>> diff --git a/mgmt/ksmbd_ida.c b/mgmt/ksmbd_ida.c > > >>>>>> index 7eb6476..34e0d2e 100644 > > >>>>>> --- a/mgmt/ksmbd_ida.c > > >>>>>> +++ b/mgmt/ksmbd_ida.c > > >>>>>> @@ -13,19 +13,14 @@ static inline int __acquire_id(struct ida *ida, > > >>>>>> int > > >>>>>> from, int to) > > >>>>>> #ifdef CONFIG_SMB_INSECURE_SERVER > > >>>>>> int ksmbd_acquire_smb1_tid(struct ida *ida) > > >>>>>> { > > >>>>>> - return __acquire_id(ida, 0, 0xFFFF); > > >>>>>> + return __acquire_id(ida, 1, 0xFFFF); > > >>>>>> } > > >>>>>> #endif > > >>>>>> > > >>>>>> int ksmbd_acquire_smb2_tid(struct ida *ida) > > >>>>>> { > > >>>>>> - int id; > > >>>>>> + return __acquire_id(ida, 1, 0); > > >>>>> > > >>>>> I think that should be __acquire_id(ida, 1, 0xFFFFFFFF) (or a lower > > >>>>> constraint) > > >>>>> > > >>>>> 0xFFFFFFFF is used for compound requests to inherit the tree id from > > >>>>> the > > >>>>> previous request. > > >>>> Where is it defined in the specification ? As I know, > > >>>> SMB2_FLAGS_RELATED_OPERATIONS flags in smb header indicate inherit > > >>>> tree id in previous request. > > >>> > > >>> [MS-SMB2] 3.2.4.1.4 Sending Compounded Requests > > >>> > > >>> ... > > >>> > > >>> The client MUST construct the subsequent request as it would do > > >>> normally. > > >>> For any subsequent > > >>> requests the client MUST set SMB2_FLAGS_RELATED_OPERATIONS in the > > >>> Flags > > >>> field of the SMB2 > > >>> header to indicate that it is using the SessionId, TreeId, and FileId > > >>> supplied in the previous > > >>> request (or generated by the server in processing that request). For > > >>> an > > >>> operation compounded > > >>> with an SMB2 CREATE request, the FileId field SHOULD be set to { > > >>> 0xFFFFFFFFFFFFFFFF, > > >>> 0xFFFFFFFFFFFFFFFF }. > > >>> > > >>> This only explicitly talks about FileId and I'm not any client would do > > >>> that, but in theory it should be possible to > > >>> compound, the 2nd session setup request (of an anonymous authentication) > > >>> with a tree connect request > > >>> and an open. > > >>> > > >>> Which means it's the safest behavior for a server to avoid 0 and all F > > >>> as > > >>> valid id, > > >>> there're still enough ids to use.... > > >>> > > >>> It also makes sure that we don't end up with very confusing network > > >>> captures. > > >> Okay, I have checked cifs client code like the following. > > >> > > >> if (request_type & CHAINED_REQUEST) { > > >> if (!(request_type & END_OF_CHAIN)) { > > >> /* next 8-byte aligned request */ > > >> *total_len = DIV_ROUND_UP(*total_len, 8) * 8; > > >> shdr->NextCommand = cpu_to_le32(*total_len); > > >> } else /* END_OF_CHAIN */ > > >> shdr->NextCommand = 0; > > >> if (request_type & RELATED_REQUEST) { > > >> shdr->Flags |= SMB2_FLAGS_RELATED_OPERATIONS; > > >> /* > > >> * Related requests use info from previous read > > >> request > > >> * in chain. > > >> */ > > >> shdr->SessionId = 0xFFFFFFFF; > > >> shdr->TreeId = 0xFFFFFFFF; > > >> req->PersistentFileId = 0xFFFFFFFF; > > >> req->VolatileFileId = 0xFFFFFFFF; > > >> } > > > > > > Which seems actually wrong and should be 0xFFFFFFFFFFFFFFFF for all but > > > TreeId... > > Oh that's right... > > > > > > metze > > > > > > > > > > > > > > > _______________________________________________ > > Linux-cifsd-devel mailing list > > Linux-cifsd-devel@lists.sourceforge.net > > https://lists.sourceforge.net/lists/listinfo/linux-cifsd-devel > > > > -- > Thanks, > > Steve -- Regards, Shyam ^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-05-19 12:02 UTC | newest] Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- [not found] <20210514125201.560775-1-mmakassikis@freebox.fr> [not found] ` <f053a063-c8e2-14c8-2c4f-a34c10c39fa1@samba.org> [not found] ` <CAKYAXd9xWW9VJ=EPrhgVUP+ES04zOnHcy4rkboAVYeOuE=bX=w@mail.gmail.com> [not found] ` <e03eb8d7-e964-5fa5-840d-9d3292d6d03f@samba.org> [not found] ` <CAKYAXd_64YRcho0Qnq+ccezVL7Tu2_9Jjb8PM+GDujZ9h8x6xw@mail.gmail.com> 2021-05-15 14:27 ` [Linux-cifsd-devel] [PATCH] cifsd: Do not use 0 as TreeID Stefan Metzmacher 2021-05-15 14:48 ` Namjae Jeon 2021-05-15 14:59 ` Steve French 2021-05-19 12:02 ` Shyam Prasad N
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