| Message ID | 20230805235106.8845-1-linkinjeon@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | ksmbd: fix wrong next length validation of ea buffer in smb2_set_ea() | expand |
diff --git a/fs/smb/server/smb2pdu.c b/fs/smb/server/smb2pdu.c index 9849d7489345..7cc1b0c47d0a 100644 --- a/fs/smb/server/smb2pdu.c +++ b/fs/smb/server/smb2pdu.c @@ -2324,9 +2324,16 @@ static int smb2_set_ea(struct smb2_ea_info *eabuf, unsigned int buf_len, break; buf_len -= next; eabuf = (struct smb2_ea_info *)((char *)eabuf + next); - if (next < (u32)eabuf->EaNameLength + le16_to_cpu(eabuf->EaValueLength)) + if (buf_len < sizeof(struct smb2_ea_info)) { + rc = -EINVAL; break; + } + if (buf_len < sizeof(struct smb2_ea_info) + eabuf->EaNameLength + + le16_to_cpu(eabuf->EaValueLength)) { + rc = -EINVAL; + break; + } } while (next != 0); kfree(attr_name);
There are multiple smb2_ea_info buffers in FILE_FULL_EA_INFORMATION request from client. ksmbd find next smb2_ea_info using ->NextEntryOffset of current smb2_ea_info. ksmbd need to validate buffer length Before accessing the next ea. ksmbd should check buffer length using buf_len, not next variable. next is the start offset of current ea that got from previous ea. Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-21598 Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> --- fs/smb/server/smb2pdu.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)