diff options
author | Hyunchul Lee <hyc.lee@gmail.com> | 2021-09-24 22:22:22 +0900 |
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committer | Steve French <stfrench@microsoft.com> | 2021-09-30 09:58:07 -0500 |
commit | 8f77150c15f87796570125a43509f9a81a3d9e49 (patch) | |
tree | 6070c7ad6684556aa7c87a45fe74fa74a64aecf5 /fs/ksmbd/oplock.c | |
parent | 442ff9ebeb0129e90483356f3d79c732e632a7a6 (diff) | |
download | linux-8f77150c15f87796570125a43509f9a81a3d9e49.tar.bz2 |
ksmbd: add buffer validation for SMB2_CREATE_CONTEXT
Add buffer validation for SMB2_CREATE_CONTEXT.
Cc: Ronnie Sahlberg <ronniesahlberg@gmail.com>
Reviewed-by: Ralph Boehme <slow@samba.org>
Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/ksmbd/oplock.c')
-rw-r--r-- | fs/ksmbd/oplock.c | 41 |
1 files changed, 31 insertions, 10 deletions
diff --git a/fs/ksmbd/oplock.c b/fs/ksmbd/oplock.c index 16b6236d1bd2..f9dae6ef2115 100644 --- a/fs/ksmbd/oplock.c +++ b/fs/ksmbd/oplock.c @@ -1451,26 +1451,47 @@ struct lease_ctx_info *parse_lease_state(void *open_req) */ struct create_context *smb2_find_context_vals(void *open_req, const char *tag) { - char *data_offset; struct create_context *cc; unsigned int next = 0; char *name; struct smb2_create_req *req = (struct smb2_create_req *)open_req; + unsigned int remain_len, name_off, name_len, value_off, value_len, + cc_len; - data_offset = (char *)req + 4 + le32_to_cpu(req->CreateContextsOffset); - cc = (struct create_context *)data_offset; + /* + * CreateContextsOffset and CreateContextsLength are guaranteed to + * be valid because of ksmbd_smb2_check_message(). + */ + cc = (struct create_context *)((char *)req + 4 + + le32_to_cpu(req->CreateContextsOffset)); + remain_len = le32_to_cpu(req->CreateContextsLength); do { - int val; - cc = (struct create_context *)((char *)cc + next); - name = le16_to_cpu(cc->NameOffset) + (char *)cc; - val = le16_to_cpu(cc->NameLength); - if (val < 4) + if (remain_len < offsetof(struct create_context, Buffer)) return ERR_PTR(-EINVAL); - if (memcmp(name, tag, val) == 0) - return cc; next = le32_to_cpu(cc->Next); + name_off = le16_to_cpu(cc->NameOffset); + name_len = le16_to_cpu(cc->NameLength); + value_off = le16_to_cpu(cc->DataOffset); + value_len = le32_to_cpu(cc->DataLength); + cc_len = next ? next : remain_len; + + if ((next & 0x7) != 0 || + next > remain_len || + name_off != offsetof(struct create_context, Buffer) || + name_len < 4 || + name_off + name_len > cc_len || + (value_off & 0x7) != 0 || + (value_off && (value_off < name_off + name_len)) || + ((u64)value_off + value_len > cc_len)) + return ERR_PTR(-EINVAL); + + name = (char *)cc + name_off; + if (memcmp(name, tag, name_len) == 0) + return cc; + + remain_len -= next; } while (next != 0); return NULL; |