linux/arch
Hari Bathini e919c0b232 bpf ppc32: Access only if addr is kernel address
With KUAP enabled, any kernel code which wants to access userspace
needs to be surrounded by disable-enable KUAP. But that is not
happening for BPF_PROBE_MEM load instruction. Though PPC32 does not
support read protection, considering the fact that PTR_TO_BTF_ID
(which uses BPF_PROBE_MEM mode) could either be a valid kernel pointer
or NULL but should never be a pointer to userspace address, execute
BPF_PROBE_MEM load only if addr is kernel address, otherwise set
dst_reg=0 and move on.

This will catch NULL, valid or invalid userspace pointers. Only bad
kernel pointer will be handled by BPF exception table.

[Alexei suggested for x86]

Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Hari Bathini <hbathini@linux.ibm.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211012123056.485795-9-hbathini@linux.ibm.com
2021-11-25 11:25:32 +11:00
..
alpha Merge branch 'akpm' (patches from Andrew) 2021-11-09 10:11:53 -08:00
arc Merge branch 'exit-cleanups-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2021-11-10 16:15:54 -08:00
arm kmap_local: don't assume kmap PTEs are linear arrays in memory 2021-11-20 10:35:54 -08:00
arm64 Selftest changes: 2021-11-18 12:05:22 -08:00
csky asm-generic: asm/syscall.h cleanup 2021-11-10 11:22:03 -08:00
h8300 Kbuild updates for v5.16 2021-11-08 09:15:45 -08:00
hexagon hexagon: ignore vmlinux.lds 2021-11-20 10:35:54 -08:00
ia64 asm-generic: asm/syscall.h cleanup 2021-11-10 11:22:03 -08:00
m68k signal: Replace force_fatal_sig with force_exit_sig when in doubt 2021-11-19 09:15:58 -06:00
microblaze asm-generic: asm/syscall.h cleanup 2021-11-10 11:22:03 -08:00
mips Selftest changes: 2021-11-18 12:05:22 -08:00
nds32 Merge branch 'exit-cleanups-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2021-11-10 16:15:54 -08:00
nios2 asm-generic: asm/syscall.h cleanup 2021-11-10 11:22:03 -08:00
openrisc Merge branch 'exit-cleanups-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2021-11-10 16:15:54 -08:00
parisc parisc: Enable CONFIG_PRINTK_TIME=y in 32bit defconfig 2021-11-18 09:02:32 +01:00
powerpc bpf ppc32: Access only if addr is kernel address 2021-11-25 11:25:32 +11:00
riscv RISC-V Fixes for 5.16-rc2 2021-11-19 11:40:14 -08:00
s390 s390 updates for 5.16-rc2 2021-11-20 10:55:50 -08:00
sh arch/sh updates for 5.16 2021-11-14 11:37:49 -08:00
sparc signal: Replace force_fatal_sig with force_exit_sig when in doubt 2021-11-19 09:15:58 -06:00
um Merge branch 'exit-cleanups-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2021-11-10 16:15:54 -08:00
x86 Two X86 fixes: 2021-11-21 11:25:19 -08:00
xtensa Merge branch 'exit-cleanups-for-v5.16' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace 2021-11-10 16:15:54 -08:00
.gitignore
Kconfig Tracing updates for 5.16: 2021-11-01 20:05:19 -07:00