Re: [PATCH] dccp: handle invalid feature options length

Gerrit Renker
2011-05-06T19:57:49Z

Quoting Dan Rosenberg:
| A length of zero (after subtracting two for the type and len fields) for
| the DCCPO_{CHANGE,CONFIRM}_{L,R} options will cause an underflow due to
| the subtraction. The subsequent code may read past the end of the
| options value buffer when parsing. I'm unsure of what the consequences
| of this might be, but it's probably not good.
|
Please disregard my earlier message, I erred.
Dan is right, his patch is correct and definitively valid.
A length of 0 would be cast to 0xff and then cause buffer overrun.

| Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com>
| Cc: stable@kernel.org
Acked-by: Gerrit Renker <gerrit@erg.abdn.ac.uk>