Re: [PATCH] iwlwifi: actually check allocated conf_tlv pointer

[Sedat Dilek]

On Mon, Apr 6, 2020 at 4:11 PM Kalle Valo <kvalo@xxxxxxxxxxxxxx> wrote:
>
> Chris Rorvick <chris@xxxxxxxxxxx> wrote:
>
> > Commit 71bc0334a637 ("iwlwifi: check allocated pointer when allocating
> > conf_tlvs") attempted to fix a typoe introduced by commit 17b809c9b22e
> > ("iwlwifi: dbg: move debug data to a struct") but does not implement the
> > check correctly.
> >
> > This can happen in OOM situations and, when it does, we will potentially try to
> > dereference a NULL pointer.
> >
> > Tweeted-by: @grsecurity
> > Signed-off-by: Chris Rorvick <chris@xxxxxxxxxxx>
>
> Fails to build, please rebase on top of wireless-drivers.
>
> drivers/net/wireless/intel/iwlwifi/iwl-drv.c: In function 'iwl_req_fw_callback':
> drivers/net/wireless/intel/iwlwifi/iwl-drv.c:1470:16: error: 'struct iwl_fw' has no member named 'dbg_conf_tlv'
>     if (!drv->fw.dbg_conf_tlv[i])
>                 ^
> make[5]: *** [drivers/net/wireless/intel/iwlwifi/iwl-drv.o] Error 1
> make[5]: *** Waiting for unfinished jobs....
> make[4]: *** [drivers/net/wireless/intel/iwlwifi] Error 2
> make[3]: *** [drivers/net/wireless/intel] Error 2
> make[2]: *** [drivers/net/wireless] Error 2
> make[1]: *** [drivers/net] Error 2
> make[1]: *** Waiting for unfinished jobs....
> make: *** [drivers] Error 2
>

Should be:

$ git diff
diff --git a/drivers/net/wireless/intel/iwlwifi/iwl-drv.c
b/drivers/net/wireless/intel/iwlwifi/iwl-drv.c
index 0481796f75bc..c24350222133 100644
--- a/drivers/net/wireless/intel/iwlwifi/iwl-drv.c
+++ b/drivers/net/wireless/intel/iwlwifi/iwl-drv.c
@@ -1467,7 +1467,7 @@ static void iwl_req_fw_callback(const struct
firmware *ucode_raw, void *context)
                                kmemdup(pieces->dbg_conf_tlv[i],
                                        pieces->dbg_conf_tlv_len[i],
                                        GFP_KERNEL);
-                       if (!pieces->dbg_conf_tlv[i])
+                       if (!drv->fw.dbg.conf_tlv[i])
                                goto out_free_fw;
                }
        }

"fw.dbg.conf" with a dot not underscore.

- Sedat -



> Patch set to Changes Requested.
>
> --
> https://patchwork.kernel.org/patch/11470125/
>
> https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches