]> git.proxmox.com Git - mirror_ubuntu-eoan-kernel.git/commit
MIPS: scall: Handle seccomp filters which redirect syscalls
authorMatt Redfearn <matt.redfearn@imgtec.com>
Tue, 29 Mar 2016 08:35:31 +0000 (09:35 +0100)
committerRalf Baechle <ralf@linux-mips.org>
Fri, 13 May 2016 12:02:00 +0000 (14:02 +0200)
commita400bed6d105c23d3673f763596e4b85de14e41a
tree9ef0d11b16f9e94aa0e890cbc0e8a74b4b5c0031
parent5050e91fa650ecd6260ef62bbed9dfc5b4d05dfa
MIPS: scall: Handle seccomp filters which redirect syscalls

Commit d218af78492a ("MIPS: scall: Always run the seccomp syscall
filters") modified the syscall code to always call the seccomp filters,
but missed the case where a filter may redirect the syscall, as
revealed by the seccomp_bpf self test.

The syscall path now restores the syscall from the stack after the
filter rather than saving it locally. Syscall number checking and
syscall function table lookup is done after the filter may have run such
that redirected syscalls are also checked, and executed.

The regular path of syscall number checking and pointer lookup is also
made more consistent between ABIs with scall64-64.S being the reference.

With this patch in place, the seccomp_bpf self test now passes
TRACE_syscall.syscall_redirected and TRACE_syscall.syscall_dropped on
all MIPS ABIs.

Fixes: d218af78492a ("MIPS: scall: Always run the seccomp syscall filters")
Signed-off-by: Matt Redfearn <matt.redfearn@imgtec.com>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Eric B Munson <emunson@akamai.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: linux-mips@linux-mips.org
Cc: IMG-MIPSLinuxKerneldevelopers@imgtec.com
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/12916/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
arch/mips/kernel/scall32-o32.S
arch/mips/kernel/scall64-64.S
arch/mips/kernel/scall64-n32.S
arch/mips/kernel/scall64-o32.S