| Message ID | 20221118150751.469393-10-nathanl@linux.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 98c738c8cee6e5a58d4060862e2f8cf3cdc8a328 |
| Headers | show |
| Series | RTAS maintenance | expand |
On Fri, 2022-11-18 at 09:07 -0600, Nathan Lynch wrote: > CONFIG_PPC_RTAS_FILTER has been optional but default-enabled since > its > introduction. It's been enabled in enterprise distro kernels for a > while without causing ABI breakage that wasn't easily fixed, and it > prevents harmful abuses of the rtas syscall. > > Let's make it unconditional. > > Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> Agreed. Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com> > --- > arch/powerpc/Kconfig | 13 ------------- > arch/powerpc/kernel/rtas.c | 16 ---------------- > 2 files changed, 29 deletions(-) > > diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > index 2ca5418457ed..8092915a4e9b 100644 > --- a/arch/powerpc/Kconfig > +++ b/arch/powerpc/Kconfig > @@ -1012,19 +1012,6 @@ config PPC_SECVAR_SYSFS > read/write operations on these variables. Say Y if you have > secure boot enabled and want to expose variables to > userspace. > > -config PPC_RTAS_FILTER > - bool "Enable filtering of RTAS syscalls" > - default y > - depends on PPC_RTAS > - help > - The RTAS syscall API has security issues that could be used > to > - compromise system integrity. This option enforces > restrictions on the > - RTAS calls and arguments passed by userspace programs to > mitigate > - these issues. > - > - Say Y unless you know what you are doing and the filter is > causing > - problems for you. > - > endmenu > > config ISA_DMA_API > diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c > index c3142d352f41..3929bcea92c0 100644 > --- a/arch/powerpc/kernel/rtas.c > +++ b/arch/powerpc/kernel/rtas.c > @@ -1051,8 +1051,6 @@ noinstr struct pseries_errorlog > *get_pseries_errorlog(struct rtas_error_log *log > return NULL; > } > > -#ifdef CONFIG_PPC_RTAS_FILTER > - > /* > * The sys_rtas syscall, as originally designed, allows root to pass > * arbitrary physical addresses to RTAS calls. A number of RTAS > calls > @@ -1201,20 +1199,6 @@ static void __init > rtas_syscall_filter_init(void) > rtas_filters[i].token = > rtas_token(rtas_filters[i].name); > } > > -#else > - > -static bool block_rtas_call(int token, int nargs, > - struct rtas_args *args) > -{ > - return false; > -} > - > -static void __init rtas_syscall_filter_init(void) > -{ > -} > - > -#endif /* CONFIG_PPC_RTAS_FILTER */ > - > /* We assume to be passed big endian arguments */ > SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs) > {
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 2ca5418457ed..8092915a4e9b 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -1012,19 +1012,6 @@ config PPC_SECVAR_SYSFS read/write operations on these variables. Say Y if you have secure boot enabled and want to expose variables to userspace. -config PPC_RTAS_FILTER - bool "Enable filtering of RTAS syscalls" - default y - depends on PPC_RTAS - help - The RTAS syscall API has security issues that could be used to - compromise system integrity. This option enforces restrictions on the - RTAS calls and arguments passed by userspace programs to mitigate - these issues. - - Say Y unless you know what you are doing and the filter is causing - problems for you. - endmenu config ISA_DMA_API diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c index c3142d352f41..3929bcea92c0 100644 --- a/arch/powerpc/kernel/rtas.c +++ b/arch/powerpc/kernel/rtas.c @@ -1051,8 +1051,6 @@ noinstr struct pseries_errorlog *get_pseries_errorlog(struct rtas_error_log *log return NULL; } -#ifdef CONFIG_PPC_RTAS_FILTER - /* * The sys_rtas syscall, as originally designed, allows root to pass * arbitrary physical addresses to RTAS calls. A number of RTAS calls @@ -1201,20 +1199,6 @@ static void __init rtas_syscall_filter_init(void) rtas_filters[i].token = rtas_token(rtas_filters[i].name); } -#else - -static bool block_rtas_call(int token, int nargs, - struct rtas_args *args) -{ - return false; -} - -static void __init rtas_syscall_filter_init(void) -{ -} - -#endif /* CONFIG_PPC_RTAS_FILTER */ - /* We assume to be passed big endian arguments */ SYSCALL_DEFINE1(rtas, struct rtas_args __user *, uargs) {
CONFIG_PPC_RTAS_FILTER has been optional but default-enabled since its introduction. It's been enabled in enterprise distro kernels for a while without causing ABI breakage that wasn't easily fixed, and it prevents harmful abuses of the rtas syscall. Let's make it unconditional. Signed-off-by: Nathan Lynch <nathanl@linux.ibm.com> --- arch/powerpc/Kconfig | 13 ------------- arch/powerpc/kernel/rtas.c | 16 ---------------- 2 files changed, 29 deletions(-)