topic Re: MFS_Create_directory_entry Edge Case bug in MQX Software Solutions

MFS_Create_directory_entry Edge Case bug

leifzars — Fri, 23 Dec 2016 03:32:51 GMT

With out the following patch the call MFS_Extend_chain returning null is not handled, and if null (due to corrupted FAT) will causes hard faults.

diff --git a/mfs/Sources/generic/mfs_dir_entry.c b/mfs/Sources/generic/mfs_dir_entry.c
index fed539f..e715003 100644
--- a/mfs/Sources/generic/mfs_dir_entry.c
+++ b/mfs/Sources/generic/mfs_dir_entry.c
@@ -348,6 +348,8 @@
{
return (NULL);
}
+ }else{
+ return NULL;
}
}
}

Re: MFS_Create_directory_entry Edge Case bug

danielchen — Fri, 23 Dec 2016 07:27:47 GMT

HI Leif:

Thank you for your feedback. Could you let us know your MQX version, and which patch?

Regards

Daniel

Re: MFS_Create_directory_entry Edge Case bug

leifzars — Fri, 23 Dec 2016 14:11:32 GMT

Version: 4.2.0.2

Re: MFS_Create_directory_entry Edge Case bug

danielchen — Mon, 26 Dec 2016 07:51:31 GMT

Hi Leif Zars

I do not find any difference in mfs_dir_entry.c between MQX 4.2.0 and patch MQX 4.2.0.2. Are you comparing the two versions? I compared MQX 4.1 and 4.2, they are different, but sees not your mentioned. How can I reproduce your issue in my side. Thanks

Regards

Daniel

Re: MFS_Create_directory_entry Edge Case bug

leifzars — Mon, 26 Dec 2016 17:07:30 GMT

Adding the highlighted section of code fixes the issue, otherwise an error returned from MFS_Extend_chain will cause a crash .

Re: MFS_Create_directory_entry Edge Case bug

danielchen — Mon, 26 Dec 2016 22:56:51 GMT

Thanks , I will discuss this issue with the developers and hope they can merge this fix in mqx v5 version.

Regards

Daniel

Re: MFS_Create_directory_entry Edge Case bug

leifzars — Mon, 26 Dec 2016 22:58:13 GMT

Good deal, thanks

Re: MFS_Create_directory_entry Edge Case bug

craig_honegger_ — Fri, 22 Sep 2017 13:03:55 GMT

This has been fixed in MQX v5 and will be available in the next release.

Thanks for reporting the issue.