Message305334
> Most, if not all, calls to _PyMem_DebugRawRealloc() are protected by
> the GIL. If there is a single thread using the memory block,
> I think that it's perfectly fine to write after it's deallocated.
I don't quite follow where the write-after-free is happening, but: C's free() function is *not* protected by the GIL. So if you're running in a multithreaded program where other threads aren't blocked by the GIL, one of these other threads could very easily allocate this freshly-freed memory. And if you wrote to it after the memory was allocated to this other thread, congrats, your program is no longer correct. |
|
Date |
User |
Action |
Args |
2017-10-31 19:32:09 | larry | set | recipients:
+ larry, vstinner, skrah, xdegaye, serhiy.storchaka, davin |
2017-10-31 19:32:09 | larry | set | messageid: <1509478329.84.0.213398074469.issue31626@psf.upfronthosting.co.za> |
2017-10-31 19:32:09 | larry | link | issue31626 messages |
2017-10-31 19:32:09 | larry | create | |
|