On Thu, Nov 17, 2022 at 09:44:24AM +0000, David Howells wrote: > Dan Carpenter <error27@xxxxxxxxx> wrote: > > > The "pkt" was supposed to have been deleted in a previous patch. It > > leads to an uninitialized variable bug. > > Weird. I don't get a compiler warning and the kernel doesn't crash, despite > transmitting millions of acks. > > If I disassemble the built code, I see: > > 0xffffffff81b09e89 <+723>: xor %edi,%edi > 0xffffffff81b09e8b <+725>: call 0xffffffff811c0bc1 <kfree> > > I'm not sure why it's sticking 0 in EDI, though. We disabled GCC's check for uninitialized variables. It could be that you have the .config to automatically zero out stack variables. CONFIG_CC_HAS_AUTO_VAR_INIT_PATTERN=y CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO_BARE=y CONFIG_CC_HAS_AUTO_VAR_INIT_ZERO=y regards, dan carpenter
