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[PATCH AUTOSEL 5.15 1/7] cifs: Fix cifs_query_path_info() for Windows NT servers

by Sasha Levin

From: Pali Rohár <pali(a)kernel.org> [ Upstream commit a3e771afbb3bce91c8296828304903e7348003fe ] For TRANS2 QUERY_PATH_INFO request when the path does not exist, the Windows NT SMB server returns error response STATUS_OBJECT_NAME_NOT_FOUND or ERRDOS/ERRbadfile without the SMBFLG_RESPONSE flag set. Similarly it returns STATUS_DELETE_PENDING when the file is being deleted. And looks like that any error response from TRANS2 QUERY_PATH_INFO does not have SMBFLG_RESPONSE flag set. So relax check in check_smb_hdr() for detecting if the packet is response for this special case. This change fixes stat() operation against Windows NT SMB servers and also all operations which depends on -ENOENT result from stat like creat() or mkdir(). Signed-off-by: Pali Rohár <pali(a)kernel.org> Signed-off-by: Steve French <stfrench(a)microsoft.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- **YES** This commit should be backported to stable kernel trees. Here's my extensive analysis: ## Backport Recommendation: YES ### Nature of the Fix This is a **targeted bug fix** that addresses a specific protocol compliance issue with Windows NT SMB servers. The commit fixes a fundamental problem where basic file operations (`stat()`, `creat()`, `mkdir()`) fail against Windows NT servers due to overly strict SMB header validation. ### Code Change Analysis The fix is remarkably **simple and contained** - only 8 lines of code in a single function: ```c /bin /bin.usr-is-merged /boot /dev /etc /home /init /lib /lib.usr- is-merged /lib64 /lost+found /media /mnt /opt /proc /root /run /sbin /sbin.usr-is-merged /snap /srv /sys /tmp /usr /var * Windows NT server returns error resposne (e.g. STATUS_DELETE_PENDING * or STATUS_OBJECT_NAME_NOT_FOUND or ERRDOS/ERRbadfile or any other) * for some TRANS2 requests without the RESPONSE flag set in header. */ if (smb->Command == SMB_COM_TRANSACTION2 && smb->Status.CifsError != 0) return 0; ``` The change is in the `check_smb_hdr()` function in `fs/smb/client/misc.c`, which validates SMB packet headers. The fix **relaxes validation** only for a very specific case: TRANS2 commands returning errors from Windows NT servers. ### Risk Assessment: LOW 1. **Surgical precision**: Only affects SMB1 TRANS2 error responses, leaving normal operation paths untouched 2. **Conservative approach**: The condition `smb->Status.CifsError != 0` ensures this only applies to actual error responses 3. **No behavioral changes** for compliant servers that properly set the RESPONSE flag 4. **Well-established code path**: The `check_smb_hdr()` function is mature and stable ### Impact Assessment: HIGH 1. **Fixes broken functionality**: Without this fix, basic file operations fail completely against Windows NT servers 2. **Backward compatibility**: Restores support for legacy but still-used server environments 3. **User-visible improvement**: Directly fixes `stat()`, `creat()`, and `mkdir()` operations 4. **No regressions**: Modern SMB servers continue to work as before ### Comparison with Similar Commits Looking at the provided similar commits: - **Similar Commit #2** (Status: YES): Also adds new status code mappings for better server compatibility - **Similar Commit #3** (Status: YES): Reduces unnecessary network roundtrips by improving error handling - **Similar Commit #4** (Status: YES): Fixes WSL reparse point querying over SMB1 - **Similar Commit #5** (Status: YES): Fixes missing resource cleanup This commit follows the **same pattern** as these approved backports: small, targeted fixes that improve compatibility and fix real-world issues without introducing new features or architectural changes. ### Technical Justification The Windows NT server behavior described in the commit is **non-compliant but real**: these servers return error responses for TRANS2 QUERY_PATH_INFO requests without setting the `SMBFLG_RESPONSE` flag. The current strict validation incorrectly treats these as invalid packets, causing the CIFS client to fail when it should handle the errors properly. The fix is **protocol-aware** and **conservative** - it only relaxes validation for the specific case where we know Windows NT behaves differently, ensuring no impact on standard-compliant servers. ### Stable Tree Suitability This commit perfectly fits stable tree criteria: - ✅ **Important bug fix** affecting real-world usage - ✅ **Minimal and contained** change with clear scope - ✅ **No new features** - purely fixes existing broken functionality - ✅ **Low regression risk** due to targeted nature - ✅ **Production-ready** code following established patterns This should be backported to all stable kernels that support SMB1 client functionality, as it fixes a fundamental compatibility issue without any meaningful risk of regression. fs/cifs/misc.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c index 33328eae03d7a..a3d37e7769e61 100644 --- a/fs/cifs/misc.c +++ b/fs/cifs/misc.c @@ -297,6 +297,14 @@ check_smb_hdr(struct smb_hdr *smb) if (smb->Command == SMB_COM_LOCKING_ANDX) return 0; + /* + * Windows NT server returns error resposne (e.g. STATUS_DELETE_PENDING + * or STATUS_OBJECT_NAME_NOT_FOUND or ERRDOS/ERRbadfile or any other) + * for some TRANS2 requests without the RESPONSE flag set in header. + */ + if (smb->Command == SMB_COM_TRANSACTION2 && smb->Status.CifsError != 0) + return 0; + cifs_dbg(VFS, "Server sent request, not response. mid=%u\n", get_mid(smb)); return 1; -- 2.39.5

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[PATCH AUTOSEL 6.6 01/13] cifs: Correctly set SMB1 SessionKey field in Session Setup Request

by Sasha Levin

From: Pali Rohár <pali(a)kernel.org> [ Upstream commit 89381c72d52094988e11d23ef24a00066a0fa458 ] [MS-CIFS] specification in section 2.2.4.53.1 where is described SMB_COM_SESSION_SETUP_ANDX Request, for SessionKey field says: The client MUST set this field to be equal to the SessionKey field in the SMB_COM_NEGOTIATE Response for this SMB connection. Linux SMB client currently set this field to zero. This is working fine against Windows NT SMB servers thanks to [MS-CIFS] product behavior <94>: Windows NT Server ignores the client's SessionKey. For compatibility with [MS-CIFS], set this SessionKey field in Session Setup Request to value retrieved from Negotiate response. Signed-off-by: Pali Rohár <pali(a)kernel.org> Signed-off-by: Steve French <stfrench(a)microsoft.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- Based on my comprehensive analysis of both the commit message and code changes, examining the current kernel tree context: **YES** ## Extensive Analysis ### **Nature of the Fix** This is a **specification compliance fix** for SMB1 protocol handling. The commit addresses a clear violation of the MS-CIFS specification section 2.2.4.53.1, which mandates that the SessionKey field in SMB_COM_SESSION_SETUP_ANDX Request must be set to the value from the SMB_COM_NEGOTIATE Response. ### **Code Changes Analysis** **1. Structural Changes (Low Risk)** - **cifsglob.h**: Adds `__le32 session_key_id` to `TCP_Server_Info` structure - minimal ABI impact as this is kernel-internal - **cifspdu.h**: Corrects endianness annotations from `__u32` to `__le32` - pure annotation fix, no behavioral change **2. Functional Changes (Contained and Safe)** - **cifssmb.c**: Captures SessionKey from negotiate response (`server->session_key_id = pSMBr->SessionKey`) - simple field assignment - **sess.c**: Sets SessionKey in session setup request (`pSMB->req.SessionKey = server->session_key_id`) - follows specification requirement ### **Risk Assessment** **Minimal Regression Risk:** - Changes are isolated to SMB1 legacy protocol code - Current behavior (setting SessionKey to zero) works with Windows NT due to MS- CIFS product behavior <94> - New behavior follows specification exactly, improving compatibility with non-Windows SMB1 servers - No security implications - purely a protocol compliance improvement **Code Maturity:** - SMB1 session setup code is very mature and stable - Limited recent changes in this area except compatibility fixes - Well- understood code path with clear specification backing ### **Backport Suitability Criteria Met** **1. Important Bug Fix:** ✅ Fixes protocol specification violation that could cause compatibility issues with strict SMB1 implementations **2. Small and Contained:** ✅ Four minimal changes across related files, all implementing the same specification requirement **3. Clear Side Effects:** ✅ No side effects beyond fixing the specification compliance issue **4. No Architectural Changes:** ✅ Simple field additions and assignments, no structural changes **5. Non- Critical Subsystem:** ✅ Legacy SMB1 protocol code, deprecated since 2017 **6. Minimal Risk:** ✅ Maintains backward compatibility while improving forward compatibility **7. Stable Tree Rules Compliance:** ✅ Important compatibility bugfix with minimal regression risk ### **Comparison to Similar Commits** This commit closely matches the pattern of **Similar Commit #3** and **Similar Commit #5** (both marked YES for backporting): - Protocol compliance improvements - Session setup related fixes - Clear specification backing - Minimal, contained changes - Authored by maintainers (Steve French involvement) ### **Conclusion** This commit represents an ideal stable backport candidate: a clear specification compliance fix with minimal code changes, no security implications, and improvement in interoperability. The fix ensures Linux kernel SMB client properly follows MS-CIFS specification, which is valuable for enterprise environments using diverse SMB1 server implementations. fs/smb/client/cifsglob.h | 1 + fs/smb/client/cifspdu.h | 6 +++--- fs/smb/client/cifssmb.c | 1 + fs/smb/client/sess.c | 1 + 4 files changed, 6 insertions(+), 3 deletions(-) diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h index 39117343b703f..1f3451202fe8d 100644 --- a/fs/smb/client/cifsglob.h +++ b/fs/smb/client/cifsglob.h @@ -739,6 +739,7 @@ struct TCP_Server_Info { char workstation_RFC1001_name[RFC1001_NAME_LEN_WITH_NULL]; __u32 sequence_number; /* for signing, protected by srv_mutex */ __u32 reconnect_instance; /* incremented on each reconnect */ + __le32 session_key_id; /* retrieved from negotiate response and send in session setup request */ struct session_key session_key; unsigned long lstrp; /* when we got last response from this server */ struct cifs_secmech secmech; /* crypto sec mech functs, descriptors */ diff --git a/fs/smb/client/cifspdu.h b/fs/smb/client/cifspdu.h index ca33f6cd6a800..763178b774542 100644 --- a/fs/smb/client/cifspdu.h +++ b/fs/smb/client/cifspdu.h @@ -557,7 +557,7 @@ typedef union smb_com_session_setup_andx { __le16 MaxBufferSize; __le16 MaxMpxCount; __le16 VcNumber; - __u32 SessionKey; + __le32 SessionKey; __le16 SecurityBlobLength; __u32 Reserved; __le32 Capabilities; /* see below */ @@ -576,7 +576,7 @@ typedef union smb_com_session_setup_andx { __le16 MaxBufferSize; __le16 MaxMpxCount; __le16 VcNumber; - __u32 SessionKey; + __le32 SessionKey; __le16 CaseInsensitivePasswordLength; /* ASCII password len */ __le16 CaseSensitivePasswordLength; /* Unicode password length*/ __u32 Reserved; /* see below */ @@ -614,7 +614,7 @@ typedef union smb_com_session_setup_andx { __le16 MaxBufferSize; __le16 MaxMpxCount; __le16 VcNumber; - __u32 SessionKey; + __le32 SessionKey; __le16 PasswordLength; __u32 Reserved; /* encrypt key len and offset */ __le16 ByteCount; diff --git a/fs/smb/client/cifssmb.c b/fs/smb/client/cifssmb.c index b91184ebce02c..096ea62e87ea9 100644 --- a/fs/smb/client/cifssmb.c +++ b/fs/smb/client/cifssmb.c @@ -479,6 +479,7 @@ CIFSSMBNegotiate(const unsigned int xid, server->max_rw = le32_to_cpu(pSMBr->MaxRawSize); cifs_dbg(NOISY, "Max buf = %d\n", ses->server->maxBuf); server->capabilities = le32_to_cpu(pSMBr->Capabilities); + server->session_key_id = pSMBr->SessionKey; server->timeAdj = (int)(__s16)le16_to_cpu(pSMBr->ServerTimeZone); server->timeAdj *= 60; diff --git a/fs/smb/client/sess.c b/fs/smb/client/sess.c index f04922eb45d4c..a7ece67ee9630 100644 --- a/fs/smb/client/sess.c +++ b/fs/smb/client/sess.c @@ -680,6 +680,7 @@ static __u32 cifs_ssetup_hdr(struct cifs_ses *ses, USHRT_MAX)); pSMB->req.MaxMpxCount = cpu_to_le16(server->maxReq); pSMB->req.VcNumber = cpu_to_le16(1); + pSMB->req.SessionKey = server->session_key_id; /* Now no need to set SMBFLG_CASELESS or obsolete CANONICAL PATH */ -- 2.39.5

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[PATCH AUTOSEL 6.12 01/15] cifs: Correctly set SMB1 SessionKey field in Session Setup Request

by Sasha Levin

From: Pali Rohár <pali(a)kernel.org> [ Upstream commit 89381c72d52094988e11d23ef24a00066a0fa458 ] [MS-CIFS] specification in section 2.2.4.53.1 where is described SMB_COM_SESSION_SETUP_ANDX Request, for SessionKey field says: The client MUST set this field to be equal to the SessionKey field in the SMB_COM_NEGOTIATE Response for this SMB connection. Linux SMB client currently set this field to zero. This is working fine against Windows NT SMB servers thanks to [MS-CIFS] product behavior <94>: Windows NT Server ignores the client's SessionKey. For compatibility with [MS-CIFS], set this SessionKey field in Session Setup Request to value retrieved from Negotiate response. Signed-off-by: Pali Rohár <pali(a)kernel.org> Signed-off-by: Steve French <stfrench(a)microsoft.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- Based on my comprehensive analysis of both the commit message and code changes, examining the current kernel tree context: **YES** ## Extensive Analysis ### **Nature of the Fix** This is a **specification compliance fix** for SMB1 protocol handling. The commit addresses a clear violation of the MS-CIFS specification section 2.2.4.53.1, which mandates that the SessionKey field in SMB_COM_SESSION_SETUP_ANDX Request must be set to the value from the SMB_COM_NEGOTIATE Response. ### **Code Changes Analysis** **1. Structural Changes (Low Risk)** - **cifsglob.h**: Adds `__le32 session_key_id` to `TCP_Server_Info` structure - minimal ABI impact as this is kernel-internal - **cifspdu.h**: Corrects endianness annotations from `__u32` to `__le32` - pure annotation fix, no behavioral change **2. Functional Changes (Contained and Safe)** - **cifssmb.c**: Captures SessionKey from negotiate response (`server->session_key_id = pSMBr->SessionKey`) - simple field assignment - **sess.c**: Sets SessionKey in session setup request (`pSMB->req.SessionKey = server->session_key_id`) - follows specification requirement ### **Risk Assessment** **Minimal Regression Risk:** - Changes are isolated to SMB1 legacy protocol code - Current behavior (setting SessionKey to zero) works with Windows NT due to MS- CIFS product behavior <94> - New behavior follows specification exactly, improving compatibility with non-Windows SMB1 servers - No security implications - purely a protocol compliance improvement **Code Maturity:** - SMB1 session setup code is very mature and stable - Limited recent changes in this area except compatibility fixes - Well- understood code path with clear specification backing ### **Backport Suitability Criteria Met** **1. Important Bug Fix:** ✅ Fixes protocol specification violation that could cause compatibility issues with strict SMB1 implementations **2. Small and Contained:** ✅ Four minimal changes across related files, all implementing the same specification requirement **3. Clear Side Effects:** ✅ No side effects beyond fixing the specification compliance issue **4. No Architectural Changes:** ✅ Simple field additions and assignments, no structural changes **5. Non- Critical Subsystem:** ✅ Legacy SMB1 protocol code, deprecated since 2017 **6. Minimal Risk:** ✅ Maintains backward compatibility while improving forward compatibility **7. Stable Tree Rules Compliance:** ✅ Important compatibility bugfix with minimal regression risk ### **Comparison to Similar Commits** This commit closely matches the pattern of **Similar Commit #3** and **Similar Commit #5** (both marked YES for backporting): - Protocol compliance improvements - Session setup related fixes - Clear specification backing - Minimal, contained changes - Authored by maintainers (Steve French involvement) ### **Conclusion** This commit represents an ideal stable backport candidate: a clear specification compliance fix with minimal code changes, no security implications, and improvement in interoperability. The fix ensures Linux kernel SMB client properly follows MS-CIFS specification, which is valuable for enterprise environments using diverse SMB1 server implementations. fs/smb/client/cifsglob.h | 1 + fs/smb/client/cifspdu.h | 6 +++--- fs/smb/client/cifssmb.c | 1 + fs/smb/client/sess.c | 1 + 4 files changed, 6 insertions(+), 3 deletions(-) diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h index a38b40d68b14f..9cd39cf96b99a 100644 --- a/fs/smb/client/cifsglob.h +++ b/fs/smb/client/cifsglob.h @@ -739,6 +739,7 @@ struct TCP_Server_Info { char workstation_RFC1001_name[RFC1001_NAME_LEN_WITH_NULL]; __u32 sequence_number; /* for signing, protected by srv_mutex */ __u32 reconnect_instance; /* incremented on each reconnect */ + __le32 session_key_id; /* retrieved from negotiate response and send in session setup request */ struct session_key session_key; unsigned long lstrp; /* when we got last response from this server */ struct cifs_secmech secmech; /* crypto sec mech functs, descriptors */ diff --git a/fs/smb/client/cifspdu.h b/fs/smb/client/cifspdu.h index 28f8ca470770d..688a26aeef3b4 100644 --- a/fs/smb/client/cifspdu.h +++ b/fs/smb/client/cifspdu.h @@ -557,7 +557,7 @@ typedef union smb_com_session_setup_andx { __le16 MaxBufferSize; __le16 MaxMpxCount; __le16 VcNumber; - __u32 SessionKey; + __le32 SessionKey; __le16 SecurityBlobLength; __u32 Reserved; __le32 Capabilities; /* see below */ @@ -576,7 +576,7 @@ typedef union smb_com_session_setup_andx { __le16 MaxBufferSize; __le16 MaxMpxCount; __le16 VcNumber; - __u32 SessionKey; + __le32 SessionKey; __le16 CaseInsensitivePasswordLength; /* ASCII password len */ __le16 CaseSensitivePasswordLength; /* Unicode password length*/ __u32 Reserved; /* see below */ @@ -614,7 +614,7 @@ typedef union smb_com_session_setup_andx { __le16 MaxBufferSize; __le16 MaxMpxCount; __le16 VcNumber; - __u32 SessionKey; + __le32 SessionKey; __le16 PasswordLength; __u32 Reserved; /* encrypt key len and offset */ __le16 ByteCount; diff --git a/fs/smb/client/cifssmb.c b/fs/smb/client/cifssmb.c index 8667f403a0ab6..c83b7aba24972 100644 --- a/fs/smb/client/cifssmb.c +++ b/fs/smb/client/cifssmb.c @@ -481,6 +481,7 @@ CIFSSMBNegotiate(const unsigned int xid, server->max_rw = le32_to_cpu(pSMBr->MaxRawSize); cifs_dbg(NOISY, "Max buf = %d\n", ses->server->maxBuf); server->capabilities = le32_to_cpu(pSMBr->Capabilities); + server->session_key_id = pSMBr->SessionKey; server->timeAdj = (int)(__s16)le16_to_cpu(pSMBr->ServerTimeZone); server->timeAdj *= 60; diff --git a/fs/smb/client/sess.c b/fs/smb/client/sess.c index 9b32f7821b718..6e48e6efe656f 100644 --- a/fs/smb/client/sess.c +++ b/fs/smb/client/sess.c @@ -655,6 +655,7 @@ static __u32 cifs_ssetup_hdr(struct cifs_ses *ses, USHRT_MAX)); pSMB->req.MaxMpxCount = cpu_to_le16(server->maxReq); pSMB->req.VcNumber = cpu_to_le16(1); + pSMB->req.SessionKey = server->session_key_id; /* Now no need to set SMBFLG_CASELESS or obsolete CANONICAL PATH */ -- 2.39.5

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[PATCH AUTOSEL 6.14 01/19] cifs: Correctly set SMB1 SessionKey field in Session Setup Request

by Sasha Levin

From: Pali Rohár <pali(a)kernel.org> [ Upstream commit 89381c72d52094988e11d23ef24a00066a0fa458 ] [MS-CIFS] specification in section 2.2.4.53.1 where is described SMB_COM_SESSION_SETUP_ANDX Request, for SessionKey field says: The client MUST set this field to be equal to the SessionKey field in the SMB_COM_NEGOTIATE Response for this SMB connection. Linux SMB client currently set this field to zero. This is working fine against Windows NT SMB servers thanks to [MS-CIFS] product behavior <94>: Windows NT Server ignores the client's SessionKey. For compatibility with [MS-CIFS], set this SessionKey field in Session Setup Request to value retrieved from Negotiate response. Signed-off-by: Pali Rohár <pali(a)kernel.org> Signed-off-by: Steve French <stfrench(a)microsoft.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- Based on my comprehensive analysis of both the commit message and code changes, examining the current kernel tree context: **YES** ## Extensive Analysis ### **Nature of the Fix** This is a **specification compliance fix** for SMB1 protocol handling. The commit addresses a clear violation of the MS-CIFS specification section 2.2.4.53.1, which mandates that the SessionKey field in SMB_COM_SESSION_SETUP_ANDX Request must be set to the value from the SMB_COM_NEGOTIATE Response. ### **Code Changes Analysis** **1. Structural Changes (Low Risk)** - **cifsglob.h**: Adds `__le32 session_key_id` to `TCP_Server_Info` structure - minimal ABI impact as this is kernel-internal - **cifspdu.h**: Corrects endianness annotations from `__u32` to `__le32` - pure annotation fix, no behavioral change **2. Functional Changes (Contained and Safe)** - **cifssmb.c**: Captures SessionKey from negotiate response (`server->session_key_id = pSMBr->SessionKey`) - simple field assignment - **sess.c**: Sets SessionKey in session setup request (`pSMB->req.SessionKey = server->session_key_id`) - follows specification requirement ### **Risk Assessment** **Minimal Regression Risk:** - Changes are isolated to SMB1 legacy protocol code - Current behavior (setting SessionKey to zero) works with Windows NT due to MS- CIFS product behavior <94> - New behavior follows specification exactly, improving compatibility with non-Windows SMB1 servers - No security implications - purely a protocol compliance improvement **Code Maturity:** - SMB1 session setup code is very mature and stable - Limited recent changes in this area except compatibility fixes - Well- understood code path with clear specification backing ### **Backport Suitability Criteria Met** **1. Important Bug Fix:** ✅ Fixes protocol specification violation that could cause compatibility issues with strict SMB1 implementations **2. Small and Contained:** ✅ Four minimal changes across related files, all implementing the same specification requirement **3. Clear Side Effects:** ✅ No side effects beyond fixing the specification compliance issue **4. No Architectural Changes:** ✅ Simple field additions and assignments, no structural changes **5. Non- Critical Subsystem:** ✅ Legacy SMB1 protocol code, deprecated since 2017 **6. Minimal Risk:** ✅ Maintains backward compatibility while improving forward compatibility **7. Stable Tree Rules Compliance:** ✅ Important compatibility bugfix with minimal regression risk ### **Comparison to Similar Commits** This commit closely matches the pattern of **Similar Commit #3** and **Similar Commit #5** (both marked YES for backporting): - Protocol compliance improvements - Session setup related fixes - Clear specification backing - Minimal, contained changes - Authored by maintainers (Steve French involvement) ### **Conclusion** This commit represents an ideal stable backport candidate: a clear specification compliance fix with minimal code changes, no security implications, and improvement in interoperability. The fix ensures Linux kernel SMB client properly follows MS-CIFS specification, which is valuable for enterprise environments using diverse SMB1 server implementations. fs/smb/client/cifsglob.h | 1 + fs/smb/client/cifspdu.h | 6 +++--- fs/smb/client/cifssmb.c | 1 + fs/smb/client/sess.c | 1 + 4 files changed, 6 insertions(+), 3 deletions(-) diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h index cddeb2adbf4af..caada3bf8b883 100644 --- a/fs/smb/client/cifsglob.h +++ b/fs/smb/client/cifsglob.h @@ -772,6 +772,7 @@ struct TCP_Server_Info { char workstation_RFC1001_name[RFC1001_NAME_LEN_WITH_NULL]; __u32 sequence_number; /* for signing, protected by srv_mutex */ __u32 reconnect_instance; /* incremented on each reconnect */ + __le32 session_key_id; /* retrieved from negotiate response and send in session setup request */ struct session_key session_key; unsigned long lstrp; /* when we got last response from this server */ struct cifs_secmech secmech; /* crypto sec mech functs, descriptors */ diff --git a/fs/smb/client/cifspdu.h b/fs/smb/client/cifspdu.h index cf9ca7e49b8bc..f5afdc5325bfa 100644 --- a/fs/smb/client/cifspdu.h +++ b/fs/smb/client/cifspdu.h @@ -597,7 +597,7 @@ typedef union smb_com_session_setup_andx { __le16 MaxBufferSize; __le16 MaxMpxCount; __le16 VcNumber; - __u32 SessionKey; + __le32 SessionKey; __le16 SecurityBlobLength; __u32 Reserved; __le32 Capabilities; /* see below */ @@ -616,7 +616,7 @@ typedef union smb_com_session_setup_andx { __le16 MaxBufferSize; __le16 MaxMpxCount; __le16 VcNumber; - __u32 SessionKey; + __le32 SessionKey; __le16 CaseInsensitivePasswordLength; /* ASCII password len */ __le16 CaseSensitivePasswordLength; /* Unicode password length*/ __u32 Reserved; /* see below */ @@ -654,7 +654,7 @@ typedef union smb_com_session_setup_andx { __le16 MaxBufferSize; __le16 MaxMpxCount; __le16 VcNumber; - __u32 SessionKey; + __le32 SessionKey; __le16 PasswordLength; __u32 Reserved; /* encrypt key len and offset */ __le16 ByteCount; diff --git a/fs/smb/client/cifssmb.c b/fs/smb/client/cifssmb.c index 4059550859a9b..68722e60fdae1 100644 --- a/fs/smb/client/cifssmb.c +++ b/fs/smb/client/cifssmb.c @@ -495,6 +495,7 @@ CIFSSMBNegotiate(const unsigned int xid, server->max_rw = le32_to_cpu(pSMBr->MaxRawSize); cifs_dbg(NOISY, "Max buf = %d\n", ses->server->maxBuf); server->capabilities = le32_to_cpu(pSMBr->Capabilities); + server->session_key_id = pSMBr->SessionKey; server->timeAdj = (int)(__s16)le16_to_cpu(pSMBr->ServerTimeZone); server->timeAdj *= 60; diff --git a/fs/smb/client/sess.c b/fs/smb/client/sess.c index 9d6b1a4704773..6d6491e035718 100644 --- a/fs/smb/client/sess.c +++ b/fs/smb/client/sess.c @@ -627,6 +627,7 @@ static __u32 cifs_ssetup_hdr(struct cifs_ses *ses, USHRT_MAX)); pSMB->req.MaxMpxCount = cpu_to_le16(server->maxReq); pSMB->req.VcNumber = cpu_to_le16(1); + pSMB->req.SessionKey = server->session_key_id; /* Now no need to set SMBFLG_CASELESS or obsolete CANONICAL PATH */ -- 2.39.5

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[PATCH AUTOSEL 6.15 01/21] cifs: Correctly set SMB1 SessionKey field in Session Setup Request

by Sasha Levin

From: Pali Rohár <pali(a)kernel.org> [ Upstream commit 89381c72d52094988e11d23ef24a00066a0fa458 ] [MS-CIFS] specification in section 2.2.4.53.1 where is described SMB_COM_SESSION_SETUP_ANDX Request, for SessionKey field says: The client MUST set this field to be equal to the SessionKey field in the SMB_COM_NEGOTIATE Response for this SMB connection. Linux SMB client currently set this field to zero. This is working fine against Windows NT SMB servers thanks to [MS-CIFS] product behavior <94>: Windows NT Server ignores the client's SessionKey. For compatibility with [MS-CIFS], set this SessionKey field in Session Setup Request to value retrieved from Negotiate response. Signed-off-by: Pali Rohár <pali(a)kernel.org> Signed-off-by: Steve French <stfrench(a)microsoft.com> Signed-off-by: Sasha Levin <sashal(a)kernel.org> --- Based on my comprehensive analysis of both the commit message and code changes, examining the current kernel tree context: **YES** ## Extensive Analysis ### **Nature of the Fix** This is a **specification compliance fix** for SMB1 protocol handling. The commit addresses a clear violation of the MS-CIFS specification section 2.2.4.53.1, which mandates that the SessionKey field in SMB_COM_SESSION_SETUP_ANDX Request must be set to the value from the SMB_COM_NEGOTIATE Response. ### **Code Changes Analysis** **1. Structural Changes (Low Risk)** - **cifsglob.h**: Adds `__le32 session_key_id` to `TCP_Server_Info` structure - minimal ABI impact as this is kernel-internal - **cifspdu.h**: Corrects endianness annotations from `__u32` to `__le32` - pure annotation fix, no behavioral change **2. Functional Changes (Contained and Safe)** - **cifssmb.c**: Captures SessionKey from negotiate response (`server->session_key_id = pSMBr->SessionKey`) - simple field assignment - **sess.c**: Sets SessionKey in session setup request (`pSMB->req.SessionKey = server->session_key_id`) - follows specification requirement ### **Risk Assessment** **Minimal Regression Risk:** - Changes are isolated to SMB1 legacy protocol code - Current behavior (setting SessionKey to zero) works with Windows NT due to MS- CIFS product behavior <94> - New behavior follows specification exactly, improving compatibility with non-Windows SMB1 servers - No security implications - purely a protocol compliance improvement **Code Maturity:** - SMB1 session setup code is very mature and stable - Limited recent changes in this area except compatibility fixes - Well- understood code path with clear specification backing ### **Backport Suitability Criteria Met** **1. Important Bug Fix:** ✅ Fixes protocol specification violation that could cause compatibility issues with strict SMB1 implementations **2. Small and Contained:** ✅ Four minimal changes across related files, all implementing the same specification requirement **3. Clear Side Effects:** ✅ No side effects beyond fixing the specification compliance issue **4. No Architectural Changes:** ✅ Simple field additions and assignments, no structural changes **5. Non- Critical Subsystem:** ✅ Legacy SMB1 protocol code, deprecated since 2017 **6. Minimal Risk:** ✅ Maintains backward compatibility while improving forward compatibility **7. Stable Tree Rules Compliance:** ✅ Important compatibility bugfix with minimal regression risk ### **Comparison to Similar Commits** This commit closely matches the pattern of **Similar Commit #3** and **Similar Commit #5** (both marked YES for backporting): - Protocol compliance improvements - Session setup related fixes - Clear specification backing - Minimal, contained changes - Authored by maintainers (Steve French involvement) ### **Conclusion** This commit represents an ideal stable backport candidate: a clear specification compliance fix with minimal code changes, no security implications, and improvement in interoperability. The fix ensures Linux kernel SMB client properly follows MS-CIFS specification, which is valuable for enterprise environments using diverse SMB1 server implementations. fs/smb/client/cifsglob.h | 1 + fs/smb/client/cifspdu.h | 6 +++--- fs/smb/client/cifssmb.c | 1 + fs/smb/client/sess.c | 1 + 4 files changed, 6 insertions(+), 3 deletions(-) diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h index 3b32116b0b496..4d097b074b5fd 100644 --- a/fs/smb/client/cifsglob.h +++ b/fs/smb/client/cifsglob.h @@ -773,6 +773,7 @@ struct TCP_Server_Info { char workstation_RFC1001_name[RFC1001_NAME_LEN_WITH_NULL]; __u32 sequence_number; /* for signing, protected by srv_mutex */ __u32 reconnect_instance; /* incremented on each reconnect */ + __le32 session_key_id; /* retrieved from negotiate response and send in session setup request */ struct session_key session_key; unsigned long lstrp; /* when we got last response from this server */ struct cifs_secmech secmech; /* crypto sec mech functs, descriptors */ diff --git a/fs/smb/client/cifspdu.h b/fs/smb/client/cifspdu.h index 1b79fe07476f6..d9cf7db0ac35e 100644 --- a/fs/smb/client/cifspdu.h +++ b/fs/smb/client/cifspdu.h @@ -597,7 +597,7 @@ typedef union smb_com_session_setup_andx { __le16 MaxBufferSize; __le16 MaxMpxCount; __le16 VcNumber; - __u32 SessionKey; + __le32 SessionKey; __le16 SecurityBlobLength; __u32 Reserved; __le32 Capabilities; /* see below */ @@ -616,7 +616,7 @@ typedef union smb_com_session_setup_andx { __le16 MaxBufferSize; __le16 MaxMpxCount; __le16 VcNumber; - __u32 SessionKey; + __le32 SessionKey; __le16 CaseInsensitivePasswordLength; /* ASCII password len */ __le16 CaseSensitivePasswordLength; /* Unicode password length*/ __u32 Reserved; /* see below */ @@ -654,7 +654,7 @@ typedef union smb_com_session_setup_andx { __le16 MaxBufferSize; __le16 MaxMpxCount; __le16 VcNumber; - __u32 SessionKey; + __le32 SessionKey; __le16 PasswordLength; __u32 Reserved; /* encrypt key len and offset */ __le16 ByteCount; diff --git a/fs/smb/client/cifssmb.c b/fs/smb/client/cifssmb.c index f55457b4b82e3..f6ec0045c5138 100644 --- a/fs/smb/client/cifssmb.c +++ b/fs/smb/client/cifssmb.c @@ -498,6 +498,7 @@ CIFSSMBNegotiate(const unsigned int xid, server->max_rw = le32_to_cpu(pSMBr->MaxRawSize); cifs_dbg(NOISY, "Max buf = %d\n", ses->server->maxBuf); server->capabilities = le32_to_cpu(pSMBr->Capabilities); + server->session_key_id = pSMBr->SessionKey; server->timeAdj = (int)(__s16)le16_to_cpu(pSMBr->ServerTimeZone); server->timeAdj *= 60; diff --git a/fs/smb/client/sess.c b/fs/smb/client/sess.c index b3fa9ee269127..d53705595a512 100644 --- a/fs/smb/client/sess.c +++ b/fs/smb/client/sess.c @@ -628,6 +628,7 @@ static __u32 cifs_ssetup_hdr(struct cifs_ses *ses, USHRT_MAX)); pSMB->req.MaxMpxCount = cpu_to_le16(server->maxReq); pSMB->req.VcNumber = cpu_to_le16(1); + pSMB->req.SessionKey = server->session_key_id; /* Now no need to set SMBFLG_CASELESS or obsolete CANONICAL PATH */ -- 2.39.5

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[PATCH] hwmon: (ftsteutates) Fix TOCTOU race in fts_read()

by Gui-Dong Han

In the fts_read() function, when handling hwmon_pwm_auto_channels_temp, the code accesses the shared variable data->fan_source[channel] twice without holding any locks. It is first checked against FTS_FAN_SOURCE_INVALID, and if the check passes, it is read again when used as an argument to the BIT() macro. This creates a Time-of-Check to Time-of-Use (TOCTOU) race condition. Another thread executing fts_update_device() can modify the value of data->fan_source[channel] between the check and its use. If the value is changed to FTS_FAN_SOURCE_INVALID (0xff) during this window, the BIT() macro will be called with a large shift value (BIT(255)). A bit shift by a value greater than or equal to the type width is undefined behavior and can lead to a crash or incorrect values being returned to userspace. Fix this by reading data->fan_source[channel] into a local variable once, eliminating the race condition. Additionally, add a bounds check to ensure the value is less than BITS_PER_LONG before passing it to the BIT() macro, making the code more robust against undefined behavior. This possible bug was found by an experimental static analysis tool developed by our team. Fixes: 1c5759d8ce05 ("hwmon: (ftsteutates) Replace fanX_source with pwmX_auto_channels_temp") Cc: stable(a)vger.kernel.org Signed-off-by: Gui-Dong Han <hanguidong02(a)gmail.com> --- drivers/hwmon/ftsteutates.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) diff --git a/drivers/hwmon/ftsteutates.c b/drivers/hwmon/ftsteutates.c index a3a07662e491..8aeec16a7a90 100644 --- a/drivers/hwmon/ftsteutates.c +++ b/drivers/hwmon/ftsteutates.c @@ -423,13 +423,16 @@ static int fts_read(struct device *dev, enum hwmon_sensor_types type, u32 attr, break; case hwmon_pwm: switch (attr) { - case hwmon_pwm_auto_channels_temp: - if (data->fan_source[channel] == FTS_FAN_SOURCE_INVALID) + case hwmon_pwm_auto_channels_temp: { + u8 fan_source = data->fan_source[channel]; + + if (fan_source == FTS_FAN_SOURCE_INVALID || fan_source >= BITS_PER_LONG) *val = 0; else - *val = BIT(data->fan_source[channel]); + *val = BIT(fan_source); return 0; + } default: break; } -- 2.25.1

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[PATCH] platform/loongarch: laptop: Unregister generic_sub_drivers on exit

by Yao Zi

Without correct unregisteration, ACPI notify handlers and the platform driver installed by generic_subdriver_init will become dangling references after removing loongson_laptop module, triggering various kernel faults when a hotkey is sent or at kernel shutdown. Cc: stable(a)vger.kernel.org Fixes: 6246ed09111f ("LoongArch: Add ACPI-based generic laptop driver") Signed-off-by: Yao Zi <ziyao(a)disroot.org> --- drivers/platform/loongarch/loongson-laptop.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/platform/loongarch/loongson-laptop.c b/drivers/platform/loongarch/loongson-laptop.c index 99203584949d..cfe2cf79dbbe 100644 --- a/drivers/platform/loongarch/loongson-laptop.c +++ b/drivers/platform/loongarch/loongson-laptop.c @@ -611,11 +611,17 @@ static int __init generic_acpi_laptop_init(void) static void __exit generic_acpi_laptop_exit(void) { + int i; + if (generic_inputdev) { - if (input_device_registered) + if (input_device_registered) { input_unregister_device(generic_inputdev); - else + + for (i = 0; i < ARRAY_SIZE(generic_sub_drivers); i++) + generic_subdriver_exit(&generic_sub_drivers[i]); + } else { input_free_device(generic_inputdev); + } } } -- 2.49.0

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[PATCH v1] mm: Close theoretical race where stale TLB entries could linger

by Ryan Roberts

Commit 3ea277194daa ("mm, mprotect: flush TLB if potentially racing with a parallel reclaim leaving stale TLB entries") described a theoretical race as such: """ Nadav Amit identified a theoritical race between page reclaim and mprotect due to TLB flushes being batched outside of the PTL being held. He described the race as follows: CPU0 CPU1 ---- ---- user accesses memory using RW PTE [PTE now cached in TLB] try_to_unmap_one() ==> ptep_get_and_clear() ==> set_tlb_ubc_flush_pending() mprotect(addr, PROT_READ) ==> change_pte_range() ==> [ PTE non-present - no flush ] user writes using cached RW PTE ... try_to_unmap_flush() The same type of race exists for reads when protecting for PROT_NONE and also exists for operations that can leave an old TLB entry behind such as munmap, mremap and madvise. """ The solution was to introduce flush_tlb_batched_pending() and call it under the PTL from mprotect/madvise/munmap/mremap to complete any pending tlb flushes. However, while madvise_free_pte_range() and madvise_cold_or_pageout_pte_range() were both retro-fitted to call flush_tlb_batched_pending() immediately after initially acquiring the PTL, they both temporarily release the PTL to split a large folio if they stumble upon one. In this case, where re-acquiring the PTL flush_tlb_batched_pending() must be called again, but it previously was not. Let's fix that. There are 2 Fixes: tags here: the first is the commit that fixed madvise_free_pte_range(). The second is the commit that added madvise_cold_or_pageout_pte_range(), which looks like it copy/pasted the faulty pattern from madvise_free_pte_range(). This is a theoretical bug discovered during code review. Cc: stable(a)vger.kernel.org Fixes: 3ea277194daa ("mm, mprotect: flush TLB if potentially racing with a parallel reclaim leaving stale TLB entries") Fixes: 9c276cc65a58 ("mm: introduce MADV_COLD") Signed-off-by: Ryan Roberts <ryan.roberts(a)arm.com> --- Applies on today's mm-unstable (3f676fe5c7a0). All mm selftests continue to pass. Thanks, Ryan mm/madvise.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/mm/madvise.c b/mm/madvise.c index 5f7a66a1617e..1d44a35ae85c 100644 --- a/mm/madvise.c +++ b/mm/madvise.c @@ -508,6 +508,7 @@ static int madvise_cold_or_pageout_pte_range(pmd_t *pmd, pte_offset_map_lock(mm, pmd, addr, &ptl); if (!start_pte) break; + flush_tlb_batched_pending(mm); arch_enter_lazy_mmu_mode(); if (!err) nr = 0; @@ -741,6 +742,7 @@ static int madvise_free_pte_range(pmd_t *pmd, unsigned long addr, start_pte = pte; if (!start_pte) break; + flush_tlb_batched_pending(mm); arch_enter_lazy_mmu_mode(); if (!err) nr = 0; -- 2.43.0

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[PATCH] drm/xe/bmg: fix compressed VRAM handling

by Matthew Auld

There looks to be an issue in our compression handling when the BO pages are very fragmented, where we choose to skip the identity map and instead fall back to emitting the PTEs by hand when migrating memory, such that we can hopefully do more work per blit operation. However in such a case we need to ensure the src PTEs are correctly tagged with a compression enabled PAT index on dgpu xe2+, otherwise the copy will simply treat the src memory as uncompressed, leading to corruption if the memory was compressed by the user. To fix this it looks like we can pass use_comp_pat into emit_pte() on the src side. There are reports of VRAM corruption in some heavy user workloads, which might be related: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/4495 Fixes: 523f191cc0c7 ("drm/xe/xe_migrate: Handle migration logic for xe2+ dgfx") Signed-off-by: Matthew Auld <matthew.auld(a)intel.com> Cc: Himal Prasad Ghimiray <himal.prasad.ghimiray(a)intel.com> Cc: Thomas Hellström <thomas.hellstrom(a)linux.intel.com> Cc: Akshata Jahagirdar <akshata.jahagirdar(a)intel.com> Cc: <stable(a)vger.kernel.org> # v6.12+ --- drivers/gpu/drm/xe/xe_migrate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpu/drm/xe/xe_migrate.c b/drivers/gpu/drm/xe/xe_migrate.c index 8f8e9fdfb2a8..16788ecf924a 100644 --- a/drivers/gpu/drm/xe/xe_migrate.c +++ b/drivers/gpu/drm/xe/xe_migrate.c @@ -863,7 +863,7 @@ struct dma_fence *xe_migrate_copy(struct xe_migrate *m, if (src_is_vram && xe_migrate_allow_identity(src_L0, &src_it)) xe_res_next(&src_it, src_L0); else - emit_pte(m, bb, src_L0_pt, src_is_vram, copy_system_ccs, + emit_pte(m, bb, src_L0_pt, src_is_vram, copy_system_ccs || use_comp_pat, &src_it, src_L0, src); if (dst_is_vram && xe_migrate_allow_identity(src_L0, &dst_it)) -- 2.49.0

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[PATCH v2 4/4] wifi: ath12k: fix dest ring-buffer corruption when ring is full

by Johan Hovold

Add the missing memory barriers to make sure that destination ring descriptors are read before updating the tail pointer (and passing ownership to the device) to avoid memory corruption on weakly ordered architectures like aarch64 when the ring is full. Tested-on: WCN7850 hw2.0 WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3 Fixes: d889913205cf ("wifi: ath12k: driver for Qualcomm Wi-Fi 7 devices") Cc: stable(a)vger.kernel.org # 6.3 Signed-off-by: Johan Hovold <johan+linaro(a)kernel.org> --- drivers/net/wireless/ath/ath12k/hal.c | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/drivers/net/wireless/ath/ath12k/hal.c b/drivers/net/wireless/ath/ath12k/hal.c index 1e2d13cc2d19..4da354e86a75 100644 --- a/drivers/net/wireless/ath/ath12k/hal.c +++ b/drivers/net/wireless/ath/ath12k/hal.c @@ -2153,7 +2153,6 @@ void ath12k_hal_srng_access_end(struct ath12k_base *ab, struct hal_srng *srng) { lockdep_assert_held(&srng->lock); - /* TODO: See if we need a write memory barrier here */ if (srng->flags & HAL_SRNG_FLAGS_LMAC_RING) { /* For LMAC rings, ring pointer updates are done through FW and * hence written to a shared memory location that is read by FW @@ -2168,7 +2167,11 @@ void ath12k_hal_srng_access_end(struct ath12k_base *ab, struct hal_srng *srng) WRITE_ONCE(*srng->u.src_ring.hp_addr, srng->u.src_ring.hp); } else { srng->u.dst_ring.last_hp = *srng->u.dst_ring.hp_addr; - *srng->u.dst_ring.tp_addr = srng->u.dst_ring.tp; + /* Make sure descriptor is read before updating the + * tail pointer. + */ + dma_mb(); + WRITE_ONCE(*srng->u.dst_ring.tp_addr, srng->u.dst_ring.tp); } } else { if (srng->ring_dir == HAL_SRNG_DIR_SRC) { @@ -2184,6 +2187,10 @@ void ath12k_hal_srng_access_end(struct ath12k_base *ab, struct hal_srng *srng) srng->u.src_ring.hp); } else { srng->u.dst_ring.last_hp = *srng->u.dst_ring.hp_addr; + /* Make sure descriptor is read before updating the + * tail pointer. + */ + mb(); ath12k_hif_write32(ab, (unsigned long)srng->u.dst_ring.tp_addr - (unsigned long)ab->mem, -- 2.49.0

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