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| author | Nathan Lynch <nathanl@linux.ibm.com> | 2022-11-18 09:07:47 -0600 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2022-12-07 22:40:43 +1100 |
| commit | 98c738c8cee6e5a58d4060862e2f8cf3cdc8a328 (patch) | |
| tree | 7b6c856d0a329652e80fda63b3a2048453541093 /arch/powerpc | |
| parent | f975b6559bac510f1b1b39637997bb240f0a9969 (diff) | |
| download | linux-98c738c8cee6e5a58d4060862e2f8cf3cdc8a328.tar.bz2 | |
powerpc/rtas: mandate RTAS syscall filtering
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>
Reviewed-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20221118150751.469393-10-nathanl@linux.ibm.com
Diffstat (limited to 'arch/powerpc')
| -rw-r--r-- | arch/powerpc/Kconfig | 13 | ||||
| -rw-r--r-- | arch/powerpc/kernel/rtas.c | 16 |
2 files changed, 0 insertions, 29 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index e21d6de797d6..65952f62ea4b 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -1044,19 +1044,6 @@ 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 10c19228aaa3..deded51a7978 100644 --- a/arch/powerpc/kernel/rtas.c +++ b/arch/powerpc/kernel/rtas.c @@ -1050,8 +1050,6 @@ 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 @@ -1200,20 +1198,6 @@ 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) { |