Description
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: zero the FS_OBJECT_ID_INFORMATION buffer before filling it in
smb2_get_info_filesystem() reports 64 bytes for FS_OBJECT_ID_INFORMATION,
that is the whole of struct object_id_info, but writes only 46 of them:
- objid[] is 16 bytes, and when the volume UUID is not available only
sizeof(stfs.f_fsid) (8) bytes are copied into it;
- extended_info.version_string[] is STRING_LENGTH (28) bytes, and only
strlen("1.1.0") (5) bytes are copied into it.
The response buffer is zeroed on allocation (kvzalloc() in
smb2_allocate_rsp_buf()), so for a standalone request the remaining 31
bytes are zero. In a compound request they need not be. The offset of
the next response is advanced by the length pinned for the previous one,
so if a preceding command wrote its reply into the buffer and then
failed, smb2_set_err_rsp() pins only the short error response and the
next reply lands inside the area that has already been written. Only
the header is cleared there:
memset((char *)rsp_hdr, 0, sizeof(struct smb2_hdr) + 2);
The client then receives up to 31 bytes of a response it was not meant
to see, including one that failed with an access denied error.
Clear the structure before filling it in. As a side effect
version_string is now NUL terminated.
ksmbd: zero the FS_OBJECT_ID_INFORMATION buffer before filling it in
smb2_get_info_filesystem() reports 64 bytes for FS_OBJECT_ID_INFORMATION,
that is the whole of struct object_id_info, but writes only 46 of them:
- objid[] is 16 bytes, and when the volume UUID is not available only
sizeof(stfs.f_fsid) (8) bytes are copied into it;
- extended_info.version_string[] is STRING_LENGTH (28) bytes, and only
strlen("1.1.0") (5) bytes are copied into it.
The response buffer is zeroed on allocation (kvzalloc() in
smb2_allocate_rsp_buf()), so for a standalone request the remaining 31
bytes are zero. In a compound request they need not be. The offset of
the next response is advanced by the length pinned for the previous one,
so if a preceding command wrote its reply into the buffer and then
failed, smb2_set_err_rsp() pins only the short error response and the
next reply lands inside the area that has already been written. Only
the header is cleared there:
memset((char *)rsp_hdr, 0, sizeof(struct smb2_hdr) + 2);
The client then receives up to 31 bytes of a response it was not meant
to see, including one that failed with an access denied error.
Clear the structure before filling it in. As a side effect
version_string is now NUL terminated.
Published:
2026-10-28
Score:
n/a
EPSS:
n/a
KEV:
No
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Remediation
No vendor fix or workaround currently provided.
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Tracking
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Advisories
No advisories yet.
References
History
Wed, 28 Oct 2026 10:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: ksmbd: zero the FS_OBJECT_ID_INFORMATION buffer before filling it in smb2_get_info_filesystem() reports 64 bytes for FS_OBJECT_ID_INFORMATION, that is the whole of struct object_id_info, but writes only 46 of them: - objid[] is 16 bytes, and when the volume UUID is not available only sizeof(stfs.f_fsid) (8) bytes are copied into it; - extended_info.version_string[] is STRING_LENGTH (28) bytes, and only strlen("1.1.0") (5) bytes are copied into it. The response buffer is zeroed on allocation (kvzalloc() in smb2_allocate_rsp_buf()), so for a standalone request the remaining 31 bytes are zero. In a compound request they need not be. The offset of the next response is advanced by the length pinned for the previous one, so if a preceding command wrote its reply into the buffer and then failed, smb2_set_err_rsp() pins only the short error response and the next reply lands inside the area that has already been written. Only the header is cleared there: memset((char *)rsp_hdr, 0, sizeof(struct smb2_hdr) + 2); The client then receives up to 31 bytes of a response it was not meant to see, including one that failed with an access denied error. Clear the structure before filling it in. As a side effect version_string is now NUL terminated. | |
| Title | ksmbd: zero the FS_OBJECT_ID_INFORMATION buffer before filling it in | |
| First Time appeared |
Linux
Linux linux Kernel |
|
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Linux
Linux linux Kernel |
|
| References |
|
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2026-10-28T10:34:30.767Z
Reserved: 2026-09-25T10:25:14.392Z
Link: CVE-2026-99113
No data.
Status : Received
Published: 2026-10-28T11:17:30.773
Modified: 2026-10-28T11:17:30.773
Link: CVE-2026-99113
No data.
OpenCVE Enrichment
No data.
Weaknesses
No weakness.