CVS commit: [netbsd-9] src/sys/compat

["Martin Husemann" <martin%netbsd.org@localhost>]

Module Name:    src
Committed By:   martin
Date:           Thu Jan  2 09:50:34 UTC 2020

Modified Files:
        src/sys/compat/common [netbsd-9]: kern_sig_43.c
        src/sys/compat/netbsd32 [netbsd-9]: netbsd32_compat_20.c
            netbsd32_compat_43.c netbsd32_compat_50.c

Log Message:
Pull up following revision(s) (requested by maxv in ticket #597):

        sys/compat/common/kern_sig_43.c: revision 1.36
        sys/compat/netbsd32/netbsd32_compat_20.c: revision 1.39
        sys/compat/netbsd32/netbsd32_compat_43.c: revision 1.59
        sys/compat/netbsd32/netbsd32_compat_50.c: revision 1.44

Fix sizeof mismatch in copyin. This leads to a user-triggerable stack
overflow. On my test build at least, by luck, the compiler orders the
variables in a way that the overflow hits only local structures which
haven't yet been initialized and used, so the overflow is harmless.

Very easily seeable with kASan - just invoke the syscall from a 32bit
binary.

Fix three stack info leaks, found by kMSan when just invoking all syscalls
with a zero page as argument.

MSan: Uninitialized Stack Memory In copyout() At Offset 0, Variable 'sb32' From compat_20_netbsd32_getfsstat()
MSan: Uninitialized Stack Memory In copyout() At Offset 12, Variable 'oss' From compat_43_sys_sigstack()
MSan: Uninitialized Stack Memory In copyout() At Offset 0, Variable 'sb' From compat_50_netbsd32___fhstat40()


To generate a diff of this commit:
cvs rdiff -u -r1.35 -r1.35.4.1 src/sys/compat/common/kern_sig_43.c
cvs rdiff -u -r1.38 -r1.38.4.1 src/sys/compat/netbsd32/netbsd32_compat_20.c
cvs rdiff -u -r1.57.4.1 -r1.57.4.2 \
    src/sys/compat/netbsd32/netbsd32_compat_43.c
cvs rdiff -u -r1.39.2.1 -r1.39.2.2 \
    src/sys/compat/netbsd32/netbsd32_compat_50.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.