Messages in this thread | | | Date | Tue, 22 Aug 2017 12:51:16 -0500 | From | Josh Poimboeuf <> | Subject | Re: [PATCH] x86/nmi/64: avoid passing user space rsp of pt_regs to nmi handler |
| |
On Tue, Aug 22, 2017 at 05:09:19PM +0000, yang oliver wrote: > From: Yong Yang <yangoliver@gmail.com> > > While NMI interrupts the very beginning of SYSCALL, the rsp could > be still user space address without loading kernel address. Then > the pt_regs constructed by the NMI entry point could have a user > space rsp. If a NMI handler tried to dump stack by using this rsp, > it can cause the kernel panic.
To me this sounds like an unwinder bug. The unwinder is supposed to have checks to prevent it from accessing user space. I know you had previously reported this for an older (pre-4.9) kernel. Have you verified the bug still exists on a recent kernel?
-- Josh
| |