On Fri, Feb 14, 2020 at 09:28:01AM +0100, Borislav Petkov wrote: > From: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > > Accessing the MCA thresholding controls in sysfs concurrently with CPU > hotplug can lead to a couple of KASAN-reported issues: > > BUG: KASAN: use-after-free in sysfs_file_ops+0x155/0x180 > Read of size 8 at addr ffff888367578940 by task grep/4019 > > and > > BUG: KASAN: use-after-free in show_error_count+0x15c/0x180 > Read of size 2 at addr ffff888368a05514 by task grep/4454 > > for example. Both result from the fact that the threshold block > creation/teardown code frees the descriptor memory itself instead of > defining proper ->release function and leaving it to the driver core to > take care of that, after all sysfs accesses have completed. > > Do that and get rid of the custom freeing code, fixing the above UAFs in > the process. > > [ bp: write commit message. ] > > Fixes: 95268664390b ("[PATCH] x86_64: mce_amd support for family 0x10 processors") > Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx> > Signed-off-by: Borislav Petkov <bp@xxxxxxx> > Cc: <stable@xxxxxxxxxxxxxxx> Damn git-send-email: it read out Cc: stable and added it to the Cc list. I've added suppresscc = bodycc to my .gitconfig. Sorry stable guys. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette