#78 Bug (endless loop with buffer overflow) in sysfs.c

[cwuensch]

I was making a small spin-off from hdparm for an embedded MIPSel device, which just sets the hdd into standby (as with parameter -y).

During this I detected a severe bug in sysfs.c:
In function sysfs_find_attr_file_path an endless loop is produced, because there is missing a

depth++;

in line 237.
This leads to infinite expansion of path, producing a buffer overflow and (in my case) some random other variables were overwritten...

I cannot really figure out, what exactly this function is meant to do. But since it is called with path=/sys/block/sda (for example) I assume that the line

        strcat(path, "/..");

should also be better placed at the end of the loop. Right?

Maybe you could inspect the whole function and its calling again?
Would be thankful for hearing your expertise...

[Mark Lord]

Fixed for next release (hdparm-9.57)

[cwuensch]

May I get the revised code?
Or could you post your changes here, please?
I could not find any source files...

[Mark Lord]

Due to other changes in the next release, the code is not yet "in shape" for passing along.
For this bug, I just ensured that the loop does do depth++ each time around. The sysfs attr that it is looking for does not always (or even often?) exist, so it's not an error to not find it.

Cheers