On Mon, Apr 3, 2023 at 8:04 AM Mickaël Salaün <mic@xxxxxxxxxxx> wrote: > > It looks like you missed my preview reviews on these patches. For reference, I believe this is Mickaël's review of the associated v6 patch: https://lore.kernel.org/linux-security-module/1ca41f67-ffa1-56c2-b4ee-f5deece95130@xxxxxxxxxxx/ > On 15/03/2023 23:46, Casey Schaufler wrote: > > Create a system call to report the list of Linux Security Modules > > that are active on the system. The list is provided as an array > > of LSM ID numbers. > > > > The calling application can use this list determine what LSM > > specific actions it might take. That might include chosing an > > output format, determining required privilege or bypassing > > security module specific behavior. > > > > Signed-off-by: Casey Schaufler <casey@xxxxxxxxxxxxxxxx> > > --- > > Documentation/userspace-api/lsm.rst | 3 +++ > > include/linux/syscalls.h | 1 + > > kernel/sys_ni.c | 1 + > > security/lsm_syscalls.c | 39 +++++++++++++++++++++++++++++ > > 4 files changed, 44 insertions(+) > > > > diff --git a/Documentation/userspace-api/lsm.rst b/Documentation/userspace-api/lsm.rst > > index b45e402302b3..a86e3817f062 100644 > > --- a/Documentation/userspace-api/lsm.rst > > +++ b/Documentation/userspace-api/lsm.rst > > @@ -63,6 +63,9 @@ Get the specified security attributes of the current process > > .. kernel-doc:: security/lsm_syscalls.c > > :identifiers: sys_lsm_get_self_attr > > > > +.. kernel-doc:: security/lsm_syscalls.c > > + :identifiers: sys_lsm_list_modules > > + > > Additional documentation > > ======================== > > > > diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h > > index 3feca00cb0c1..f755c583f949 100644 > > --- a/include/linux/syscalls.h > > +++ b/include/linux/syscalls.h > > @@ -1063,6 +1063,7 @@ asmlinkage long sys_lsm_get_self_attr(unsigned int attr, struct lsm_ctx *ctx, > > size_t *size, __u64 flags); > > asmlinkage long sys_lsm_set_self_attr(unsigned int attr, struct lsm_ctx *ctx, > > __u64 flags); > > +asmlinkage long sys_lsm_list_modules(u64 *ids, size_t *size, u32 flags); > > > > /* > > * Architecture-specific system calls > > diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c > > index d03c78ef1562..ceb3d21a62d0 100644 > > --- a/kernel/sys_ni.c > > +++ b/kernel/sys_ni.c > > @@ -265,6 +265,7 @@ COND_SYSCALL(mremap); > > /* security/lsm_syscalls.c */ > > COND_SYSCALL(lsm_get_self_attr); > > COND_SYSCALL(lsm_set_self_attr); > > +COND_SYSCALL(lsm_list_modules); > > > > /* security/keys/keyctl.c */ > > COND_SYSCALL(add_key); > > diff --git a/security/lsm_syscalls.c b/security/lsm_syscalls.c > > index feee31600219..6efbe244d304 100644 > > --- a/security/lsm_syscalls.c > > +++ b/security/lsm_syscalls.c > > @@ -53,3 +53,42 @@ SYSCALL_DEFINE4(lsm_get_self_attr, unsigned int, attr, struct lsm_ctx __user *, > > { > > return security_getselfattr(attr, ctx, size, flags); > > } > > + > > +/** > > + * sys_lsm_list_modules - Return a list of the active security modules > > + * @ids: the LSM module ids > > + * @size: size of @ids, updated on return > > + * @flags: reserved for future use, must be zero > > + * > > + * Returns a list of the active LSM ids. On success this function > > + * returns the number of @ids array elements. This value may be zero > > + * if there are no LSMs active. If @size is insufficient to contain > > + * the return data -E2BIG is returned and @size is set to the minimum > > + * required size. In all other cases a negative value indicating the > > + * error is returned. > > + */ > > +SYSCALL_DEFINE3(lsm_list_modules, u64 __user *, ids, size_t __user *, size, > > + u32, flags) > > +{ > > + size_t total_size = lsm_active_cnt * sizeof(*ids); > > + size_t usize; > > + int i; > > + > > + if (flags) > > + return -EINVAL; > > + > > + if (get_user(usize, size)) > > + return -EFAULT; > > + > > + if (put_user(total_size, size) != 0) > > + return -EFAULT; > > + > > + if (usize < total_size) > > + return -E2BIG; > > + > > + for (i = 0; i < lsm_active_cnt; i++) > > + if (put_user(lsm_idlist[i]->id, ids++)) > > + return -EFAULT; > > + > > + return lsm_active_cnt; > > +} -- paul-moore.com
