fwctl: pds: Validate RPC input size before parsing

The fwctl core allocates the device-specific RPC input buffer with
fwctl_rpc.in_len and passes that buffer to the driver callback.

pdsfc_fw_rpc() casts the buffer to struct fwctl_rpc_pds and then calls
pdsfc_validate_rpc(), which reads fields from that structure before
checking that the input buffer is large enough to contain it. A short
in_len can make pds_fwctl read beyond the allocation.

Reject pds RPC buffers that are smaller than struct fwctl_rpc_pds before
parsing any pds-specific fields.

Fixes: 92c66ee829b9 ("pds_fwctl: add rpc and query support")
Link: https://patch.msgid.link/r/20260517062232.1858747-1-gganji11@naver.com
Cc: stable@vger.kernel.org # v6.15+
Signed-off-by: Heechan Kang <gganji11@naver.com>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

diff --git a/drivers/fwctl/pds/main.c b/drivers/fwctl/pds/main.c
index 08872ee8422f843120bd937f36da4b9231b9bca2..68fe254dd10adc46156a1806139a03b913a1710a 100644 (file)
--- a/drivers/fwctl/pds/main.c
+++ b/drivers/fwctl/pds/main.c
@@ -362,6 +362,9 @@ static void *pdsfc_fw_rpc(struct fwctl_uctx *uctx, enum fwctl_rpc_scope scope,
        void *out = NULL;
        int err;
 
+       if (in_len < sizeof(*rpc))
+               return ERR_PTR(-EINVAL);
+
        err = pdsfc_validate_rpc(pdsfc, rpc, scope);
        if (err)
                return ERR_PTR(err);