diff options
| author | Namjae Jeon <linkinjeon@kernel.org> | 2026-06-13 22:00:02 +0900 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2026-06-16 18:57:22 -0500 |
| commit | cedff600f1642aa982178503552f0d007bc829c8 (patch) | |
| tree | fa7becae55fc78a387f2f81d263c1865c75588e2 | |
| parent | b383bcad3d2fe634b26efbce53e22bbb5753a520 (diff) | |
ksmbd: require source read access for duplicate extents
FSCTL_DUPLICATE_EXTENTS_TO_FILE passes the source file directly to
vfs_clone_file_range() or vfs_copy_file_range() without checking the SMB
access mask granted to the source handle. A handle opened with attribute
access can consequently be used to copy file contents into an
attacker-readable destination.
Require FILE_READ_DATA on the source handle before either VFS operation,
matching other ksmbd data-copy paths.
Cc: stable@vger.kernel.org
Reported-by: Musaab Khan <musaab.khan@protonmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
| -rw-r--r-- | fs/smb/server/smb2pdu.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index 6d3f975d582f..fcb1bcd5de95 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -8778,6 +8778,10 @@ int smb2_ioctl(struct ksmbd_work *work) ret = -EACCES; goto dup_ext_out; } + if (!(fp_in->daccess & FILE_READ_DATA_LE)) { + ret = -EACCES; + goto dup_ext_out; + } src_off = le64_to_cpu(dup_ext->SourceFileOffset); dst_off = le64_to_cpu(dup_ext->TargetFileOffset); |