seccomp: add new helper call seccomp_load_filter_set()

This allows us to unify most of the code in apply_protect_kernel_modules() and
apply_private_devices().
This commit is contained in:
Lennart Poettering 2016-10-21 21:18:46 +02:00
parent 60f547cf68
commit a3be2849b2
3 changed files with 28 additions and 32 deletions

View File

@ -1502,9 +1502,6 @@ finish:
}
static int apply_protect_kernel_modules(Unit *u, const ExecContext *c) {
scmp_filter_ctx seccomp;
int r;
assert(c);
/* Turn off module syscalls on ProtectKernelModules=yes */
@ -1512,25 +1509,10 @@ static int apply_protect_kernel_modules(Unit *u, const ExecContext *c) {
if (skip_seccomp_unavailable(u, "ProtectKernelModules="))
return 0;
r = seccomp_init_conservative(&seccomp, SCMP_ACT_ALLOW);
if (r < 0)
return r;
r = seccomp_add_syscall_filter_set(seccomp, syscall_filter_sets + SYSCALL_FILTER_SET_MODULE, SCMP_ACT_ERRNO(EPERM));
if (r < 0)
goto finish;
r = seccomp_load(seccomp);
finish:
seccomp_release(seccomp);
return r;
return seccomp_load_filter_set(SCMP_ACT_ALLOW, syscall_filter_sets + SYSCALL_FILTER_SET_MODULE, SCMP_ACT_ERRNO(EPERM));
}
static int apply_private_devices(Unit *u, const ExecContext *c) {
scmp_filter_ctx seccomp;
int r;
assert(c);
/* If PrivateDevices= is set, also turn off iopl and all @raw-io syscalls. */
@ -1538,19 +1520,7 @@ static int apply_private_devices(Unit *u, const ExecContext *c) {
if (skip_seccomp_unavailable(u, "PrivateDevices="))
return 0;
r = seccomp_init_conservative(&seccomp, SCMP_ACT_ALLOW);
if (r < 0)
return r;
r = seccomp_add_syscall_filter_set(seccomp, syscall_filter_sets + SYSCALL_FILTER_SET_RAW_IO, SCMP_ACT_ERRNO(EPERM));
if (r < 0)
goto finish;
r = seccomp_load(seccomp);
finish:
seccomp_release(seccomp);
return r;
return seccomp_load_filter_set(SCMP_ACT_ALLOW, syscall_filter_sets + SYSCALL_FILTER_SET_RAW_IO, SCMP_ACT_ERRNO(EPERM));
}
#endif

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@ -452,3 +452,27 @@ int seccomp_add_syscall_filter_set(scmp_filter_ctx seccomp, const SyscallFilterS
return 0;
}
int seccomp_load_filter_set(uint32_t default_action, const SyscallFilterSet *set, uint32_t action) {
scmp_filter_ctx seccomp;
int r;
assert(set);
/* The one-stop solution: allocate a seccomp object, add a filter to it, and apply it */
r = seccomp_init_conservative(&seccomp, default_action);
if (r < 0)
return r;
r = seccomp_add_syscall_filter_set(seccomp, set, action);
if (r < 0)
goto finish;
r = seccomp_load(seccomp);
finish:
seccomp_release(seccomp);
return r;
}

View File

@ -59,3 +59,5 @@ extern const SyscallFilterSet syscall_filter_sets[];
const SyscallFilterSet *syscall_filter_set_find(const char *name);
int seccomp_add_syscall_filter_set(scmp_filter_ctx seccomp, const SyscallFilterSet *set, uint32_t action);
int seccomp_load_filter_set(uint32_t default_action, const SyscallFilterSet *set, uint32_t action);