Messages in this thread | | | Date | Tue, 18 May 2021 02:14:14 +0200 | From | Eugene Syromiatnikov <> | Subject | Re: [PATCH v26 24/30] x86/cet/shstk: Introduce shadow stack token setup/verify routines |
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On Mon, May 17, 2021 at 01:55:01PM -0700, Yu, Yu-cheng wrote: > On 5/17/2021 12:45 AM, Borislav Petkov wrote: > >On Tue, Apr 27, 2021 at 01:43:09PM -0700, Yu-cheng Yu wrote: > >>+static inline int write_user_shstk_32(u32 __user *addr, u32 val) > >>+{ > >>+ WARN_ONCE(1, "%s used but not supported.\n", __func__); > >>+ return -EFAULT; > >>+} > >>+#endif > > > >What is that supposed to catch? Any concrete (mis-)use cases? > > > > If 32-bit apps are not supported, there should be no need of 32-bit shadow > stack write, otherwise there is a bug.
Speaking of which, I wonder what would happen if a 64-bit process makes a 32-bit system call (using int 0x80, for example), and gets a signal.
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