diff options
36 files changed, 603 insertions, 284 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index e31c87474739..55762cba8516 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -7953,6 +7953,16 @@ S: Maintained F: drivers/mmc/host/sdhci.* F: drivers/mmc/host/sdhci-pltfm.[ch] +SECURE COMPUTING +M: Kees Cook <keescook@chromium.org> +T: git git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git seccomp +S: Supported +F: kernel/seccomp.c +F: include/uapi/linux/seccomp.h +F: include/linux/seccomp.h +K: \bsecure_computing +K: \bTIF_SECCOMP\b + SECURE DIGITAL HOST CONTROLLER INTERFACE, OPEN FIRMWARE BINDINGS (SDHCI-OF) M: Anton Vorontsov <anton@enomsg.org> L: linuxppc-dev@lists.ozlabs.org diff --git a/arch/Kconfig b/arch/Kconfig index 97ff872c7acc..0eae9df35b88 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -321,6 +321,7 @@ config HAVE_ARCH_SECCOMP_FILTER - secure_computing is called from a ptrace_event()-safe context - secure_computing return value is checked and a return value of -1 results in the system call being skipped immediately. + - seccomp syscall wired up config SECCOMP_FILTER def_bool y diff --git a/arch/arm/include/uapi/asm/unistd.h b/arch/arm/include/uapi/asm/unistd.h index ba94446c72d9..e21b4a069701 100644 --- a/arch/arm/include/uapi/asm/unistd.h +++ b/arch/arm/include/uapi/asm/unistd.h @@ -409,6 +409,7 @@ #define __NR_sched_setattr (__NR_SYSCALL_BASE+380) #define __NR_sched_getattr (__NR_SYSCALL_BASE+381) #define __NR_renameat2 (__NR_SYSCALL_BASE+382) +#define __NR_seccomp (__NR_SYSCALL_BASE+383) /* * This may need to be greater than __NR_last_syscall+1 in order to diff --git a/arch/arm/kernel/calls.S b/arch/arm/kernel/calls.S index 8f51bdcdacbb..bea85f97f363 100644 --- a/arch/arm/kernel/calls.S +++ b/arch/arm/kernel/calls.S @@ -392,6 +392,7 @@ /* 380 */ CALL(sys_sched_setattr) CALL(sys_sched_getattr) CALL(sys_renameat2) + CALL(sys_seccomp) #ifndef syscalls_counted .equ syscalls_padding, ((NR_syscalls + 3) & ~3) - NR_syscalls #define syscalls_counted diff --git a/arch/mips/include/uapi/asm/unistd.h b/arch/mips/include/uapi/asm/unistd.h index 5805414777e0..9bc13eaf9d67 100644 --- a/arch/mips/include/uapi/asm/unistd.h +++ b/arch/mips/include/uapi/asm/unistd.h @@ -372,16 +372,17 @@ #define __NR_sched_setattr (__NR_Linux + 349) #define __NR_sched_getattr (__NR_Linux + 350) #define __NR_renameat2 (__NR_Linux + 351) +#define __NR_seccomp (__NR_Linux + 352) /* * Offset of the last Linux o32 flavoured syscall */ -#define __NR_Linux_syscalls 351 +#define __NR_Linux_syscalls 352 #endif /* _MIPS_SIM == _MIPS_SIM_ABI32 */ #define __NR_O32_Linux 4000 -#define __NR_O32_Linux_syscalls 351 +#define __NR_O32_Linux_syscalls 352 #if _MIPS_SIM == _MIPS_SIM_ABI64 @@ -701,16 +702,17 @@ #define __NR_sched_setattr (__NR_Linux + 309) #define __NR_sched_getattr (__NR_Linux + 310) #define __NR_renameat2 (__NR_Linux + 311) +#define __NR_seccomp (__NR_Linux + 312) /* * Offset of the last Linux 64-bit flavoured syscall */ -#define __NR_Linux_syscalls 311 +#define __NR_Linux_syscalls 312 #endif /* _MIPS_SIM == _MIPS_SIM_ABI64 */ #define __NR_64_Linux 5000 -#define __NR_64_Linux_syscalls 311 +#define __NR_64_Linux_syscalls 312 #if _MIPS_SIM == _MIPS_SIM_NABI32 @@ -1034,15 +1036,16 @@ #define __NR_sched_setattr (__NR_Linux + 313) #define __NR_sched_getattr (__NR_Linux + 314) #define __NR_renameat2 (__NR_Linux + 315) +#define __NR_seccomp (__NR_Linux + 316) /* * Offset of the last N32 flavoured syscall */ -#define __NR_Linux_syscalls 315 +#define __NR_Linux_syscalls 316 #endif /* _MIPS_SIM == _MIPS_SIM_NABI32 */ #define __NR_N32_Linux 6000 -#define __NR_N32_Linux_syscalls 315 +#define __NR_N32_Linux_syscalls 316 #endif /* _UAPI_ASM_UNISTD_H */ diff --git a/arch/mips/kernel/scall32-o32.S b/arch/mips/kernel/scall32-o32.S index 3245474f19d5..ab02d14f1b5c 100644 --- a/arch/mips/kernel/scall32-o32.S +++ b/arch/mips/kernel/scall32-o32.S @@ -578,3 +578,4 @@ EXPORT(sys_call_table) PTR sys_sched_setattr PTR sys_sched_getattr /* 4350 */ PTR sys_renameat2 + PTR sys_seccomp diff --git a/arch/mips/kernel/scall64-64.S b/arch/mips/kernel/scall64-64.S index be2fedd4ae33..010dccf128ec 100644 --- a/arch/mips/kernel/scall64-64.S +++ b/arch/mips/kernel/scall64-64.S @@ -431,4 +431,5 @@ EXPORT(sys_call_table) PTR sys_sched_setattr PTR sys_sched_getattr /* 5310 */ PTR sys_renameat2 + PTR sys_seccomp .size sys_call_table,.-sys_call_table diff --git a/arch/mips/kernel/scall64-n32.S b/arch/mips/kernel/scall64-n32.S index c1dbcda4b816..c3b3b6525df5 100644 --- a/arch/mips/kernel/scall64-n32.S +++ b/arch/mips/kernel/scall64-n32.S @@ -424,4 +424,5 @@ EXPORT(sysn32_call_table) PTR sys_sched_setattr PTR sys_sched_getattr PTR sys_renameat2 /* 6315 */ + PTR sys_seccomp .size sysn32_call_table,.-sysn32_call_table diff --git a/arch/mips/kernel/scall64-o32.S b/arch/mips/kernel/scall64-o32.S index f1343ccd7ed7..bb1550b1f501 100644 --- a/arch/mips/kernel/scall64-o32.S +++ b/arch/mips/kernel/scall64-o32.S @@ -557,4 +557,5 @@ EXPORT(sys32_call_table) PTR sys_sched_setattr PTR sys_sched_getattr /* 4350 */ PTR sys_renameat2 + PTR sys_seccomp .size sys32_call_table,.-sys32_call_table diff --git a/arch/x86/syscalls/syscall_32.tbl b/arch/x86/syscalls/syscall_32.tbl index d6b867921612..7527eac24122 100644 --- a/arch/x86/syscalls/syscall_32.tbl +++ b/arch/x86/syscalls/syscall_32.tbl @@ -360,3 +360,4 @@ 351 i386 sched_setattr sys_sched_setattr 352 i386 sched_getattr sys_sched_getattr 353 i386 renameat2 sys_renameat2 +354 i386 seccomp sys_seccomp diff --git a/arch/x86/syscalls/syscall_64.tbl b/arch/x86/syscalls/syscall_64.tbl index ec255a1646d2..16272a6c12b7 100644 --- a/arch/x86/syscalls/syscall_64.tbl +++ b/arch/x86/syscalls/syscall_64.tbl @@ -323,6 +323,7 @@ 314 common sched_setattr sys_sched_setattr 315 common sched_getattr sys_sched_getattr 316 common renameat2 sys_renameat2 +317 common seccomp sys_seccomp # # x32-specific system call numbers start at 512 to avoid cache impact diff --git a/fs/exec.c b/fs/exec.c index a3d33fe592d6..ab1f1200ce5d 100644 --- a/fs/exec.c +++ b/fs/exec.c @@ -1216,7 +1216,7 @@ EXPORT_SYMBOL(install_exec_creds); /* * determine how safe it is to execute the proposed program * - the caller must hold ->cred_guard_mutex to protect against - * PTRACE_ATTACH + * PTRACE_ATTACH or seccomp thread-sync */ static void check_unsafe_exec(struct linux_binprm *bprm) { @@ -1234,7 +1234,7 @@ static void check_unsafe_exec(struct linux_binprm *bprm) * This isn't strictly necessary, but it makes it harder for LSMs to * mess up. */ - if (current->no_new_privs) + if (task_no_new_privs(current)) bprm->unsafe |= LSM_UNSAFE_NO_NEW_PRIVS; t = p; @@ -1272,7 +1272,7 @@ int prepare_binprm(struct linux_binprm *bprm) bprm->cred->egid = current_egid(); if (!(bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID) && - !current->no_new_privs && + !task_no_new_privs(current) && kuid_has_mapping(bprm->cred->user_ns, inode->i_uid) && kgid_has_mapping(bprm->cred->user_ns, inode->i_gid)) { /* Set-uid? */ diff --git a/include/linux/sched.h b/include/linux/sched.h index 306f4f0c987a..0fd19055bb64 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1307,13 +1307,12 @@ struct task_struct { * execve */ unsigned in_iowait:1; - /* task may not gain privileges */ - unsigned no_new_privs:1; - /* Revert to default priority/policy when forking */ unsigned sched_reset_on_fork:1; unsigned sched_contributes_to_load:1; + unsigned long atomic_flags; /* Flags needing atomic access. */ + pid_t pid; pid_t tgid; @@ -1967,6 +1966,19 @@ static inline void memalloc_noio_restore(unsigned int flags) current->flags = (current->flags & ~PF_MEMALLOC_NOIO) | flags; } +/* Per-process atomic flags. */ +#define PFA_NO_NEW_PRIVS 0x00000001 /* May not gain new privileges. */ + +static inline bool task_no_new_privs(struct task_struct *p) +{ + return test_bit(PFA_NO_NEW_PRIVS, &p->atomic_flags); +} + +static inline void task_set_no_new_privs(struct task_struct *p) +{ + set_bit(PFA_NO_NEW_PRIVS, &p->atomic_flags); +} + /* * task->jobctl flags */ diff --git a/include/linux/seccomp.h b/include/linux/seccomp.h index 4054b0994071..5d586a45a319 100644 --- a/include/linux/seccomp.h +++ b/include/linux/seccomp.h @@ -3,6 +3,8 @@ #include <uapi/linux/seccomp.h> +#define SECCOMP_FILTER_FLAG_MASK (SECCOMP_FILTER_FLAG_TSYNC) + #ifdef CONFIG_SECCOMP #include <linux/thread_info.h> @@ -14,11 +16,11 @@ struct seccomp_filter; * * @mode: indicates one of the valid values above for controlled * system calls available to a process. - * @filter: The metadata and ruleset for determining what system calls - * are allowed for a task. + * @filter: must always point to a valid seccomp-filter or NULL as it is + * accessed without locking during system call entry. * * @filter must only be accessed from the context of current as there - * is no locking. + * is no read locking. */ struct seccomp { int mode; diff --git a/include/linux/syscalls.h b/include/linux/syscalls.h index b0881a0ed322..1713977ee26f 100644 --- a/include/linux/syscalls.h +++ b/include/linux/syscalls.h @@ -866,4 +866,6 @@ asmlinkage long sys_process_vm_writev(pid_t pid, asmlinkage long sys_kcmp(pid_t pid1, pid_t pid2, int type, unsigned long idx1, unsigned long idx2); asmlinkage long sys_finit_module(int fd, const char __user *uargs, int flags); +asmlinkage long sys_seccomp(unsigned int op, unsigned int flags, + const char __user *uargs); #endif diff --git a/include/uapi/asm-generic/unistd.h b/include/uapi/asm-generic/unistd.h index 333640608087..65acbf0e2867 100644 --- a/include/uapi/asm-generic/unistd.h +++ b/include/uapi/asm-generic/unistd.h @@ -699,9 +699,11 @@ __SYSCALL(__NR_sched_setattr, sys_sched_setattr) __SYSCALL(__NR_sched_getattr, sys_sched_getattr) #define __NR_renameat2 276 __SYSCALL(__NR_renameat2, sys_renameat2) +#define __NR_seccomp 277 +__SYSCALL(__NR_seccomp, sys_seccomp) #undef __NR_syscalls -#define __NR_syscalls 277 +#define __NR_syscalls 278 /* * All syscalls below here should go away really, diff --git a/include/uapi/linux/seccomp.h b/include/uapi/linux/seccomp.h index ac2dc9f72973..0f238a43ff1e 100644 --- a/include/uapi/linux/seccomp.h +++ b/include/uapi/linux/seccomp.h @@ -10,6 +10,13 @@ #define SECCOMP_MODE_STRICT 1 /* uses hard-coded filter. */ #define SECCOMP_MODE_FILTER 2 /* uses user-supplied filter. */ +/* Valid operations for seccomp syscall. */ +#define SECCOMP_SET_MODE_STRICT 0 +#define SECCOMP_SET_MODE_FILTER 1 + +/* Valid flags for SECCOMP_SET_MODE_FILTER */ +#define SECCOMP_FILTER_FLAG_TSYNC 1 + /* * All BPF programs must return a 32-bit value. * The bottom 16-bits are for optional return data. diff --git a/kernel/fork.c b/kernel/fork.c index 6a13c46cd87d..ed4bc339c9dc 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -315,6 +315,15 @@ static struct task_struct *dup_task_struct(struct task_struct *orig) goto free_ti; tsk->stack = ti; +#ifdef CONFIG_SECCOMP + /* + * We must handle setting up seccomp filters once we're under + * the sighand lock in case orig has changed between now and + * then. Until then, filter must be NULL to avoid messing up + * the usage counts on the error path calling free_task. + */ + tsk->seccomp.filter = NULL; +#endif setup_thread_stack(tsk, orig); clear_user_return_notifier(tsk); @@ -1081,6 +1090,39 @@ static int copy_signal(unsigned long clone_flags, struct task_struct *tsk) return 0; } +static void copy_seccomp(struct task_struct *p) +{ +#ifdef CONFIG_SECCOMP + /* + * Must be called with sighand->lock held, which is common to + * all threads in the group. Holding cred_guard_mutex is not + * needed because this new task is not yet running and cannot + * be racing exec. + */ + BUG_ON(!spin_is_locked(¤t->sighand->siglock)); + + /* Ref-count the new filter user, and assign it. */ + get_seccomp_filter(current); + p->seccomp = current->seccomp; + + /* + * Explicitly enable no_new_privs here in case it got set + * between the task_struct being duplicated and holding the + * sighand lock. The seccomp state and nnp must be in sync. + */ + if (task_no_new_privs(current)) + task_set_no_new_privs(p); + + /* + * If the parent gained a seccomp mode after copying thread + * flags and between before we held the sighand lock, we have + * to manually enable the seccomp thread flag here. + */ + if (p->seccomp.mode != SECCOMP_MODE_DISABLED) + set_tsk_thread_flag(p, TIF_SECCOMP); +#endif +} + SYSCALL_DEFINE1(set_tid_address, int __user *, tidptr) { current->clear_child_tid = tidptr; @@ -1196,7 +1238,6 @@ static struct task_struct *copy_process(unsigned long clone_flags, goto fork_out; ftrace_graph_init_task(p); - get_seccomp_filter(p); rt_mutex_init_task(p); @@ -1437,6 +1478,12 @@ static struct task_struct *copy_process(unsigned long clone_flags, spin_lock(¤t->sighand->siglock); /* + * Copy seccomp details explicitly here, in case they were changed + * before holding sighand lock. + */ + copy_seccomp(p); + + /* * Process group and session signals need to be delivered to just the * parent before the fork or both the parent and the child after the * fork. Restart if a signal comes in before we add the new process to diff --git a/kernel/seccomp.c b/kernel/seccomp.c index 301bbc24739c..74f460179171 100644 --- a/kernel/seccomp.c +++ b/kernel/seccomp.c @@ -18,15 +18,17 @@ #include <linux/compat.h> #include <linux/sched.h> #include <linux/seccomp.h> +#include <linux/slab.h> +#include <linux/syscalls.h> /* #define SECCOMP_DEBUG 1 */ #ifdef CONFIG_SECCOMP_FILTER #include <asm/syscall.h> #include <linux/filter.h> +#include <linux/pid.h> #include <linux/ptrace.h> #include <linux/security.h> -#include <linux/slab.h> #include <linux/tracehook.h> #include <linux/uaccess.h> @@ -172,21 +174,24 @@ static int seccomp_check_filter(struct sock_filter *filter, unsigned int flen) */ static u32 seccomp_run_filters(int syscall) { - struct seccomp_filter *f; + struct seccomp_filter *f = ACCESS_ONCE(current->seccomp.filter); struct seccomp_data sd; u32 ret = SECCOMP_RET_ALLOW; /* Ensure unexpected behavior doesn't result in failing open. */ - if (WARN_ON(current->seccomp.filter == NULL)) + if (unlikely(WARN_ON(f == NULL))) return SECCOMP_RET_KILL; + /* Make sure cross-thread synced filter points somewhere sane. */ + smp_read_barrier_depends(); + populate_seccomp_data(&sd); /* * All filters in the list are evaluated and the lowest BPF return * value always takes priority (ignoring the DATA). */ - for (f = current->seccomp.filter; f; f = f->prev) { + for (; f; f = f->prev) { u32 cur_ret = SK_RUN_FILTER(f->prog, (void *)&sd); if ((cur_ret & SECCOMP_RET_ACTION) < (ret & SECCOMP_RET_ACTION)) @@ -194,29 +199,159 @@ static u32 seccomp_run_filters(int syscall) } return ret; } +#endif /* CONFIG_SECCOMP_FILTER */ + +static inline bool seccomp_may_assign_mode(unsigned long seccomp_mode) +{ + BUG_ON(!spin_is_locked(¤t->sighand->siglock)); + + if (current->seccomp.mode && current->seccomp.mode != seccomp_mode) + return false; + + return true; +} + +static inline void seccomp_assign_mode(struct task_struct *task, + unsigned long seccomp_mode) +{ + BUG_ON(!spin_is_locked(&task->sighand->siglock)); + + task->seccomp.mode = seccomp_mode; + /* + * Make sure TIF_SECCOMP cannot be set before the mode (and + * filter) is set. + */ + smp_mb__before_atomic(); + set_tsk_thread_flag(task, TIF_SECCOMP); +} + +#ifdef CONFIG_SECCOMP_FILTER +/* Returns 1 if the parent is an ancestor of the child. */ +static int is_ancestor(struct seccomp_filter *parent, + struct seccomp_filter *child) +{ + /* NULL is the root ancestor. */ + if (parent == NULL) + return 1; + for (; child; child = child->prev) + if (child == parent) + return 1; + return 0; +} /** - * seccomp_attach_filter: Attaches a seccomp filter to current. + * seccomp_can_sync_threads: checks if all threads can be synchronized + * + * Expects sighand and cred_guard_mutex locks to be held. + * + * Returns 0 on success, -ve on error, or the pid of a thread which was + * either not in the correct seccomp mode or it did not have an ancestral + * seccomp filter. + */ +static inline pid_t seccomp_can_sync_threads(void) +{ + struct task_struct *thread, *caller; + + BUG_ON(!mutex_is_locked(¤t->signal->cred_guard_mutex)); + BUG_ON(!spin_is_locked(¤t->sighand->siglock)); + + /* Validate all threads being eligible for synchronization. */ + caller = current; + for_each_thread(caller, thread) { + pid_t failed; + + /* Skip current, since it is initiating the sync. */ + if (thread == caller) + continue; + + if (thread->seccomp.mode == SECCOMP_MODE_DISABLED || + (thread->seccomp.mode == SECCOMP_MODE_FILTER && + is_ancestor(thread->seccomp.filter, + caller->seccomp.filter))) + continue; + + /* Return the first thread that cannot be synchronized. */ + failed = task_pid_vnr(thread); + /* If the pid cannot be resolved, then return -ESRCH */ + if (unlikely(WARN_ON(failed == 0))) + failed = -ESRCH; + return failed; + } + + return 0; +} + +/** + * seccomp_sync_threads: sets all threads to use current's filter + * + * Expects sighand and cred_guard_mutex locks to be held, and for + * seccomp_can_sync_threads() to have returned success already + * without dropping the locks. + * + */ +static inline void seccomp_sync_threads(void) +{ + struct task_struct *thread, *caller; + + BUG_ON(!mutex_is_locked(¤t->signal->cred_guard_mutex)); + BUG_ON(!spin_is_locked(¤t->sighand->siglock)); + + /* Synchronize all threads. */ + caller = current; + for_each_thread(caller, thread) { + /* Skip current, since it needs no changes. */ + if (thread == caller) + continue; + + /* Get a task reference for the new leaf node. */ + get_seccomp_filter(caller); + /* + * Drop the task reference to the shared ancestor since + * current's path will hold a reference. (This also + * allows a put before the assignment.) + */ + put_seccomp_filter(thread); + smp_store_release(&thread->seccomp.filter, + caller->seccomp.filter); + /* + * Opt the other thread into seccomp if needed. + * As threads are considered to be trust-realm + * equivalent (see ptrace_may_access), it is safe to + * allow one thread to transition the other. + */ + if (thread->seccomp.mode == SECCOMP_MODE_DISABLED) { + /* + * Don't let an unprivileged task work around + * the no_new_privs restriction by creating + * a thread that sets it up, enters seccomp, + * then dies. + */ + if (task_no_new_privs(caller)) + task_set_no_new_privs(thread); + + seccomp_assign_mode(thread, SECCOMP_MODE_FILTER); + } + } +} + +/** + * seccomp_prepare_filter: Prepares a seccomp filter for use. * @fprog: BPF program to install * - * Returns 0 on success or an errno on failure. + * Returns filter on success or an ERR_PTR on failure. */ -static long seccomp_attach_filter(struct sock_fprog *fprog) +static struct seccomp_filter *seccomp_prepare_filter(struct sock_fprog *fprog) { struct seccomp_filter *filter; - unsigned long fp_size = fprog->len * sizeof(struct sock_filter); - unsigned long total_insns = fprog->len; + unsigned long fp_size; struct sock_filter *fp; int new_len; long ret; if (fprog->len == 0 || fprog->len > BPF_MAXINSNS) - return -EINVAL; - - for (filter = current->seccomp.filter; filter; filter = filter->prev) - total_insns += filter->prog->len + 4; /* include a 4 instr penalty */ - if (total_insns > MAX_INSNS_PER_PATH) - return -ENOMEM; + return ERR_PTR(-EINVAL); + BUG_ON(INT_MAX / fprog->len < sizeof(struct sock_filter)); + fp_size = fprog->len * sizeof(struct sock_filter); /* * Installing a seccomp filter requires that the task has @@ -224,14 +359,14 @@ static long seccomp_attach_filter(struct sock_fprog *fprog) * This avoids scenarios where unprivileged tasks can affect the * behavior of privileged children. */ - if (!current->no_new_privs && + if (!task_no_new_privs(current) && security_capable_noaudit(current_cred(), current_user_ns(), CAP_SYS_ADMIN) != 0) - return -EACCES; + return ERR_PTR(-EACCES); fp = kzalloc(fp_size, GFP_KERNEL|__GFP_NOWARN); if (!fp) - return -ENOMEM; + return ERR_PTR(-ENOMEM); /* Copy the instructions from fprog. */ ret = -EFAULT; @@ -275,13 +410,7 @@ static long seccomp_attach_filter(struct sock_fprog *fprog) sk_filter_select_runtime(filter->prog); - /* - * If there is an existing filter, make it the prev and don't drop its - * task reference. - */ - filter->prev = current->seccomp.filter; - current->seccomp.filter = filter; - return 0; + return filter; free_filter_prog: kfree(filter->prog); @@ -289,19 +418,20 @@ free_filter: kfree(filter); free_prog: kfree(fp); - return ret; + return ERR_PTR(ret); } /** - * seccomp_attach_user_filter - attaches a user-supplied sock_fprog + * seccomp_prepare_user_filter - prepares a user-supplied sock_fprog * @user_filter: pointer to the user data containing a sock_fprog. * * Returns 0 on success and non-zero otherwise. */ -static long seccomp_attach_user_filter(char __user *user_filter) +static struct seccomp_filter * +seccomp_prepare_user_filter(const char __user *user_filter) { struct sock_fprog fprog; - long ret = -EFAULT; + struct seccomp_filter *filter = ERR_PTR(-EFAULT); #ifdef CONFIG_COMPAT if (is_compat_task()) { @@ -314,9 +444,56 @@ static long seccomp_attach_user_filter(char __user *user_filter) #endif if (copy_from_user(&fprog, user_filter, sizeof(fprog))) goto out; - ret = seccomp_attach_filter(&fprog); + filter = seccomp_prepare_filter(&fprog); out: - return ret; + return filter; +} + +/** + * seccomp_attach_filter: validate and attach filter + * @flags: flags to change filter behavior + * @filter: seccomp filter to add to the current process + * + * Caller must be holding current->sighand->siglock lock. + * + * Returns 0 on success, -ve on error. + */ +static long seccomp_attach_filter(unsigned int flags, + struct seccomp_filter *filter) +{ + unsigned long total_insns; + struct seccomp_filter *walker; + + BUG_ON(!spin_is_locked(¤t->sighand->siglock)); + + /* Validate resulting filter length. */ + total_insns = filter->prog->len; + for (walker = current->seccomp.filter; walker; walker = walker->prev) + total_insns += walker->prog->len + 4; /* 4 instr penalty */ + if (total_insns > MAX_INSNS_PER_PATH) + return -ENOMEM; + + /* If thread sync has been requested, check that it is possible. */ + if (flags & SECCOMP_FILTER_FLAG_TSYNC) { + int ret; + + ret = seccomp_can_sync_threads(); + if (ret) + return ret; + } + + /* + * If there is an existing filter, make it the prev and don't drop its + * task reference. + */ + filter->prev = current->seccomp.filter; + current->seccomp.filter = filter; + + /* Now that the new filter is in place, synchronize to all threads. */ + if (flags & SECCOMP_FILTER_FLAG_TSYNC) + seccomp_sync_threads(); + + return 0; } /* get_seccomp_filter - increments the reference count of the filter on @tsk */ @@ -329,6 +506,14 @@ void get_seccomp_filter(struct task_struct *tsk) atomic_inc(&orig->usage); } +static inline void seccomp_filter_free(struct seccomp_filter *filter) +{ + if (filter) { + sk_filter_free(filter->prog); + kfree(filter); + } +} + /* put_seccomp_filter - decrements the ref count of tsk->seccomp.filter */ void put_seccomp_filter(struct task_struct *tsk) { @@ -337,8 +522,7 @@ void put_seccomp_filter(struct task_struct *tsk) while (orig && atomic_dec_and_test(&orig->usage)) { struct seccomp_filter *freeme = orig; orig = orig->prev; - sk_filter_free(freeme->prog); - kfree(freeme); + seccomp_filter_free(freeme); } } @@ -382,12 +566,17 @@ static int mode1_syscalls_32[] = { int __secure_computing(int this_syscall) { - int mode = current->seccomp.mode; int exit_sig = 0; int *syscall; u32 ret; - switch (mode) { + /* + * Make sure that any changes to mode from another thread have + * been seen after TIF_SECCOMP was seen. + */ + rmb(); + + switch (current->seccomp.mode) { case SECCOMP_MODE_STRICT: syscall = mode1_syscalls; #ifdef CONFIG_COMPAT @@ -473,47 +662,152 @@ long prctl_get_seccomp(void) } /** - * prctl_set_seccomp: configures current->seccomp.mode - * @seccomp_mode: requested mode to use - * @filter: optional struct sock_fprog for use with SECCOMP_MODE_FILTER + * seccomp_set_mode_strict: internal function for setting strict seccomp * - * This function may be called repeatedly with a @seccomp_mode of - * SECCOMP_MODE_FILTER to install additional filters. Every filter - * successfully installed will be evaluated (in reverse order) for each system - * call the task makes. + * Once current->seccomp.mode is non-zero, it may not be changed. + * + * Returns 0 on success or -EINVAL on failure. + */ +static long seccomp_set_mode_strict(void) +{ + const unsigned long seccomp_mode = SECCOMP_MODE_STRICT; + long ret = -EINVAL; + + spin_lock_irq(¤t->sighand->siglock); + + if (!seccomp_may_assign_mode(seccomp_mode)) + goto out; + +#ifdef TIF_NOTSC + disable_TSC(); +#endif + seccomp_assign_mode(current, seccomp_mode); + ret = 0; + +out: + spin_unlock_irq(¤t->sighand->siglock); + + return ret; +} + +#ifdef CONFIG_SECCOMP_FILTER +/** + * seccomp_set_mode_filter: internal function for setting seccomp filter + * @flags: flags to change filter behavior + * @filter: struct sock_fprog containing filter + * + * This function may be called repeatedly to install additional filters. + * Every filter successfully installed will be evaluated (in reverse order) + * for each system call the task makes. * * Once current->seccomp.mode is non-zero, it may not be changed. * * Returns 0 on success or -EINVAL on failure. */ -long prctl_set_seccomp(unsigned long seccomp_mode, char __user *filter) +static long seccomp_set_mode_filter(unsigned int flags, + const char __user *filter) { + const unsigned long seccomp_mode = SECCOMP_MODE_FILTER; + struct seccomp_filter *prepared = NULL; long ret = -EINVAL; - if (current->seccomp.mode && - current->seccomp.mode != seccomp_mode) + /* Validate flags. */ + if (flags & ~SECCOMP_FILTER_FLAG_MASK) + return -EINVAL; + + /* Prepare the new filter before holding any locks. */ + prepared = seccomp_prepare_user_filter(filter); + if (IS_ERR(prepared)) + return PTR_ERR(prepared); + + /* + * Make sure we cannot change seccomp or nnp state via TSYNC + * while another thread is in the middle of calling exec. + */ + if (flags & SECCOMP_FILTER_FLAG_TSYNC && + mutex_lock_killable(¤t->signal->cred_guard_mutex)) + goto out_free; + + spin_lock_irq(¤t->sighand->siglock); + + if (!seccomp_may_assign_mode(seccomp_mode)) + goto out; + + ret = seccomp_attach_filter(flags, prepared); + if (ret) goto out; + /* Do not free the successfully attached filter. */ + prepared = NULL; + + seccomp_assign_mode(current, seccomp_mode); +out: + spin_unlock_irq(¤t->sighand->siglock); + if (flags & SECCOMP_FILTER_FLAG_TSYNC) + mutex_unlock(¤t->signal->cred_guard_mutex); +out_free: + seccomp_filter_free(prepared); + return ret; +} +#else +static inline long seccomp_set_mode_filter(unsigned int flags, + const char __user *filter) +{ + return -EINVAL; +} +#endif + +/* Common entry point for both prctl and syscall. */ +static long do_seccomp(unsigned int op, unsigned int flags, + const char __user *uargs) +{ + switch (op) { + case SECCOMP_SET_MODE_STRICT: + if (flags != 0 || uargs != NULL) + return -EINVAL; + return seccomp_set_mode_strict(); + case SECCOMP_SET_MODE_FILTER: + return seccomp_set_mode_filter(flags, uargs); + default: + return -EINVAL; + } +} + +SYSCALL_DEFINE3(seccomp, unsigned int, op, unsigned int, flags, + const char __user *, uargs) +{ + return do_seccomp(op, flags, uargs); +} + +/** + * prctl_set_seccomp: configures current->seccomp.mode + * @seccomp_mode: requested mode to use + * @filter: optional struct sock_fprog for use with SECCOMP_MODE_FILTER + * + * Returns 0 on success or -EINVAL on failure. + */ +long prctl_set_seccomp(unsigned long seccomp_mode, char __user *filter) +{ + unsigned int op; + char __user *uargs; switch (seccomp_mode) { case SECCOMP_MODE_STRICT: - ret = 0; -#ifdef TIF_NOTSC - disable_TSC(); -#endif + op = SECCOMP_SET_MODE_STRICT; + /* + * Setting strict mode through prctl always ignored filter, + * so make sure it is always NULL here to pass the internal + * check in do_seccomp(). + */ + uargs = NULL; break; -#ifdef CONFIG_SECCOMP_FILTER case SECCOMP_MODE_FILTER: - ret = seccomp_attach_user_filter(filter); - if (ret) - goto out; + op = SECCOMP_SET_MODE_FILTER; + uargs = filter; break; -#endif default: - goto out; + return -EINVAL; } - current->seccomp.mode = seccomp_mode; - set_thread_flag(TIF_SECCOMP); -out: - return ret; + /* prctl interface doesn't have flags, so they are always zero. */ + return do_seccomp(op, 0, uargs); } diff --git a/kernel/sys.c b/kernel/sys.c index 66a751ebf9d9..ce8129192a26 100644 --- a/kernel/sys.c +++ b/kernel/sys.c @@ -1990,12 +1990,12 @@ SYSCALL_DEFINE5(prctl, int, option, unsigned long, arg2, unsigned long, arg3, if (arg2 != 1 || arg3 || arg4 || arg5) return -EINVAL; - current->no_new_privs = 1; + task_set_no_new_privs(current); break; case PR_GET_NO_NEW_PRIVS: if (arg2 || arg3 || arg4 || arg5) return -EINVAL; - return current->no_new_privs ? 1 : 0; + return task_no_new_privs(current) ? 1 : 0; case PR_GET_THP_DISABLE: if (arg2 || arg3 || arg4 || arg5) return -EINVAL; diff --git a/kernel/sys_ni.c b/kernel/sys_ni.c index 36441b51b5df..2904a2105914 100644 --- a/kernel/sys_ni.c +++ b/kernel/sys_ni.c @@ -213,3 +213,6 @@ cond_syscall(compat_sys_open_by_handle_at); /* compare kernel pointers */ cond_syscall(sys_kcmp); + +/* operate on Secure Computing state */ +cond_syscall(sys_seccomp); diff --git a/scripts/selinux/genheaders/Makefile b/scripts/selinux/genheaders/Makefile index 417b165008ee..1d1ac51359e3 100644 --- a/scripts/selinux/genheaders/Makefile +++ b/scripts/selinux/genheaders/Makefile @@ -2,4 +2,3 @@ hostprogs-y := genheaders HOST_EXTRACFLAGS += -Isecurity/selinux/include always := $(hostprogs-y) -clean-files := $(hostprogs-y) diff --git a/scripts/selinux/mdp/Makefile b/scripts/selinux/mdp/Makefile index eb365b333441..dba7eff69a00 100644 --- a/scripts/selinux/mdp/Makefile +++ b/scripts/selinux/mdp/Makefile @@ -2,4 +2,4 @@ hostprogs-y := mdp HOST_EXTRACFLAGS += -Isecurity/selinux/include always := $(hostprogs-y) -clean-files := $(hostprogs-y) policy.* file_contexts +clean-files := policy.* file_contexts diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c index 452567d3a08e..d97cba3e3849 100644 --- a/security/apparmor/domain.c +++ b/security/apparmor/domain.c @@ -621,7 +621,7 @@ int aa_change_hat(const char *hats[], int count, u64 token, bool permtest) * There is no exception for unconfined as change_hat is not * available. */ - if (current->no_new_privs) + if (task_no_new_privs(current)) return -EPERM; /* released below */ @@ -776,7 +776,7 @@ int aa_change_profile(const char *ns_name, const char *hname, bool onexec, * no_new_privs is set because this aways results in a reduction * of permissions. */ - if (current->no_new_privs && !unconfined(profile)) { + if (task_no_new_privs(current) && !unconfined(profile)) { put_cred(cred); return -EPERM; } diff --git a/security/commoncap.c b/security/commoncap.c index b9d613e0ef14..9fe46e22c7f2 100644 --- a/security/commoncap.c +++ b/security/commoncap.c @@ -822,15 +822,20 @@ int cap_task_setnice(struct task_struct *p, int nice) * Implement PR_CAPBSET_DROP. Attempt to remove the specified capability from * the current task's bounding set. Returns 0 on success, -ve on error. */ -static long cap_prctl_drop(struct cred *new, unsigned long cap) +static int cap_prctl_drop(unsigned long cap) { + struct cred *new; + if (!ns_capable(current_user_ns(), CAP_SETPCAP)) return -EPERM; if (!cap_valid(cap)) return -EINVAL; + new = prepare_creds(); + if (!new) + return -ENOMEM; cap_lower(new->cap_bset, cap); - return 0; + return commit_creds(new); } /** @@ -848,26 +853,17 @@ static long cap_prctl_drop(struct cred *new, unsigned long cap) int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, unsigned long arg4, unsigned long arg5) { + const struct cred *old = current_cred(); struct cred *new; - long error = 0; - - new = prepare_creds(); - if (!new) - return -ENOMEM; switch (option) { case PR_CAPBSET_READ: - error = -EINVAL; if (!cap_valid(arg2)) - goto error; - error = !!cap_raised(new->cap_bset, arg2); - goto no_change; + return -EINVAL; + return !!cap_raised(old->cap_bset, arg2); case PR_CAPBSET_DROP: - error = cap_prctl_drop(new, arg2); - if (error < 0) - goto error; - goto changed; + return cap_prctl_drop(arg2); /* * The next four prctl's remain to assist with transitioning a @@ -889,10 +885,9 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, * capability-based-privilege environment. */ case PR_SET_SECUREBITS: - error = -EPERM; - if ((((new->securebits & SECURE_ALL_LOCKS) >> 1) - & (new->securebits ^ arg2)) /*[1]*/ - || ((new->securebits & SECURE_ALL_LOCKS & ~arg2)) /*[2]*/ + if ((((old->securebits & SECURE_ALL_LOCKS) >> 1) + & (old->securebits ^ arg2)) /*[1]*/ + || ((old->securebits & SECURE_ALL_LOCKS & ~arg2)) /*[2]*/ || (arg2 & ~(SECURE_ALL_LOCKS | SECURE_ALL_BITS)) /*[3]*/ || (cap_capable(current_cred(), current_cred()->user_ns, CAP_SETPCAP, @@ -906,46 +901,39 @@ int cap_task_prctl(int option, unsigned long arg2, unsigned long arg3, */ ) /* cannot change a locked bit */ - goto error; + return -EPERM; + + new = prepare_creds(); + if (!new) + return -ENOMEM; new->securebits = arg2; - goto changed; + return commit_creds(new); case PR_GET_SECUREBITS: - error = new->securebits; - goto no_change; + return old->securebits; case PR_GET_KEEPCAPS: - if (issecure(SECURE_KEEP_CAPS)) - error = 1; - goto no_change; + return !!issecure(SECURE_KEEP_CAPS); case PR_SET_KEEPCAPS: - error = -EINVAL; if (arg2 > 1) /* Note, we rely on arg2 being unsigned here */ - goto error; - error = -EPERM; + return -EINVAL; if (issecure(SECURE_KEEP_CAPS_LOCKED)) - goto error; + return -EPERM; + + new = prepare_creds(); + if (!new) + return -ENOMEM; if (arg2) new->securebits |= issecure_mask(SECURE_KEEP_CAPS); else new->securebits &= ~issecure_mask(SECURE_KEEP_CAPS); - goto changed; + return commit_creds(new); default: /* No functionality available - continue with default */ - error = -ENOSYS; - goto error; + return -ENOSYS; } - - /* Functionality provided */ -changed: - return commit_creds(new); - -no_change: -error: - abort_creds(new); - return error; } /** diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index a1ac1c5c729b..7740f61588d6 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -161,6 +161,17 @@ static int selinux_peerlbl_enabled(void) return (selinux_policycap_alwaysnetwork || netlbl_enabled() || selinux_xfrm_enabled()); } +static int selinux_netcache_avc_callback(u32 event) +{ + if (event == AVC_CALLBACK_RESET) { + sel_netif_flush(); + sel_netnode_flush(); + sel_netport_flush(); + synchronize_net(); + } + return 0; +} + /* * initialise the security for the init task */ @@ -6002,6 +6013,9 @@ static __init int selinux_init(void) if (register_security(&selinux_ops)) panic("SELinux: Unable to register with kernel.\n"); + if (avc_add_callback(selinux_netcache_avc_callback, AVC_CALLBACK_RESET)) + panic("SELinux: Unable to register AVC netcache callback\n"); + if (selinux_enforcing) printk(KERN_DEBUG "SELinux: Starting in enforcing mode\n"); else diff --git a/security/selinux/include/netif.h b/security/selinux/include/netif.h index 43d507242b42..57c6eae81eac 100644 --- a/security/selinux/include/netif.h +++ b/security/selinux/include/netif.h @@ -17,6 +17,8 @@ #ifndef _SELINUX_NETIF_H_ #define _SELINUX_NETIF_H_ +void sel_netif_flush(void); + int sel_netif_sid(int ifindex, u32 *sid); #endif /* _SELINUX_NETIF_H_ */ diff --git a/security/selinux/include/netnode.h b/security/selinux/include/netnode.h index df7a5ed6c694..937668dd3024 100644 --- a/security/selinux/include/netnode.h +++ b/security/selinux/include/netnode.h @@ -27,6 +27,8 @@ #ifndef _SELINUX_NETNODE_H #define _SELINUX_NETNODE_H +void sel_netnode_flush(void); + int sel_netnode_sid(void *addr, u16 family, u32 *sid); #endif diff --git a/security/selinux/include/netport.h b/security/selinux/include/netport.h index 4d965b83d735..d1ce896b2cb0 100644 --- a/security/selinux/include/netport.h +++ b/security/selinux/include/netport.h @@ -26,6 +26,8 @@ #ifndef _SELINUX_NETPORT_H #define _SELINUX_NETPORT_H +void sel_netport_flush(void); + int sel_netport_sid(u8 protocol, u16 pnum, u32 *sid); #endif diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h index ce7852cf526b..d1e0b239b602 100644 --- a/security/selinux/include/security.h +++ b/security/selinux/include/security.h @@ -8,6 +8,7 @@ #ifndef _SELINUX_SECURITY_H_ #define _SELINUX_SECURITY_H_ +#include <linux/compiler.h> #include <linux/dcache.h> #include <linux/magic.h> #include <linux/types.h> @@ -220,7 +221,7 @@ struct selinux_kernel_status { /* * The version > 0 supports above members. */ -} __attribute__((packed)); +} __packed; extern void selinux_status_update_setenforce(int enforcing); extern void selinux_status_update_policyload(int seqno); diff --git a/security/selinux/netif.c b/security/selinux/netif.c index 694e9e43855f..3c3de4ca0ebc 100644 --- a/security/selinux/netif.c +++ b/security/selinux/netif.c @@ -240,7 +240,7 @@ static void sel_netif_kill(int ifindex) * Remove all entries from the network interface table. * */ -static void sel_netif_flush(void) +void sel_netif_flush(void) { int idx; struct sel_netif *netif; @@ -252,15 +252,6 @@ static void sel_netif_flush(void) spin_unlock_bh(&sel_netif_lock); } -static int sel_netif_avc_callback(u32 event) -{ - if (event == AVC_CALLBACK_RESET) { - sel_netif_flush(); - synchronize_net(); - } - return 0; -} - static int sel_netif_netdev_notifier_handler(struct notifier_block *this, unsigned long event, void *ptr) { @@ -291,10 +282,6 @@ static __init int sel_netif_init(void) register_netdevice_notifier(&sel_netif_netdev_notifier); - err = avc_add_callback(sel_netif_avc_callback, AVC_CALLBACK_RESET); - if (err) - panic("avc_add_callback() failed, error %d\n", err); - return err; } diff --git a/security/selinux/netnode.c b/security/selinux/netnode.c index 03a72c32afd7..ddf315260839 100644 --- a/security/selinux/netnode.c +++ b/security/selinux/netnode.c @@ -283,7 +283,7 @@ int sel_netnode_sid(void *addr, u16 family, u32 *sid) * Remove all entries from the network address table. * */ -static void sel_netnode_flush(void) +void sel_netnode_flush(void) { unsigned int idx; struct sel_netnode *node, *node_tmp; @@ -300,15 +300,6 @@ static void sel_netnode_flush(void) spin_unlock_bh(&sel_netnode_lock); } -static int sel_netnode_avc_callback(u32 event) -{ - if (event == AVC_CALLBACK_RESET) { - sel_netnode_flush(); - synchronize_net(); - } - return 0; -} - static __init int sel_netnode_init(void) { int iter; @@ -322,10 +313,6 @@ static __init int sel_netnode_init(void) sel_netnode_hash[iter].size = 0; } - ret = avc_add_callback(sel_netnode_avc_callback, AVC_CALLBACK_RESET); - if (ret != 0) - panic("avc_add_callback() failed, error %d\n", ret); - return ret; } diff --git a/security/selinux/netport.c b/security/selinux/netport.c index d35379781c2c..73ac6784d091 100644 --- a/security/selinux/netport.c +++ b/security/selinux/netport.c @@ -217,7 +217,7 @@ int sel_netport_sid(u8 protocol, u16 pnum, u32 *sid) * Remove all entries from the network address table. * */ -static void sel_netport_flush(void) +void sel_netport_flush(void) { unsigned int idx; struct sel_netport *port, *port_tmp; @@ -234,15 +234,6 @@ static void sel_netport_flush(void) spin_unlock_bh(&sel_netport_lock); } -static int sel_netport_avc_callback(u32 event) -{ - if (event == AVC_CALLBACK_RESET) { - sel_netport_flush(); - synchronize_net(); - } - return 0; -} - static __init int sel_netport_init(void) { int iter; @@ -256,10 +247,6 @@ static __init int sel_netport_init(void) sel_netport_hash[iter].size = 0; } - ret = avc_add_callback(sel_netport_avc_callback, AVC_CALLBACK_RESET); - if (ret != 0) - panic("avc_add_callback() failed, error %d\n", ret); - return ret; } diff --git a/security/selinux/ss/conditional.c b/security/selinux/ss/conditional.c index 377d148e7157..62c6773be0b7 100644 --- a/security/selinux/ss/conditional.c +++ b/security/selinux/ss/conditional.c @@ -402,19 +402,14 @@ static int cond_read_node(struct policydb *p, struct cond_node *node, void *fp) int rc; struct cond_expr *expr = NULL, *last = NULL; - rc = next_entry(buf, fp, sizeof(u32)); + rc = next_entry(buf, fp, sizeof(u32) * 2); if (rc) - return rc; + goto err; node->cur_state = le32_to_cpu(buf[0]); - len = 0; - rc = next_entry(buf, fp, sizeof(u32)); - if (rc) - return rc; - /* expr */ - len = le32_to_cpu(buf[0]); + len = le32_to_cpu(buf[1]); for (i = 0; i < len; i++) { rc = next_entry(buf, fp, sizeof(u32) * 2); diff --git a/security/selinux/ss/policydb.c b/security/selinux/ss/policydb.c index 9c5cdc2caaef..bc2a586f095c 100644 --- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -1080,6 +1080,26 @@ out: * binary representation file. */ +static int str_read(char **strp, gfp_t flags, void *fp, u32 len) +{ + int rc; + char *str; + + str = kmalloc(len + 1, flags); + if (!str) + return -ENOMEM; + + /* it's expected the caller should free the str */ + *strp = str; + + rc = next_entry(str, fp, len); + if (rc) + return rc; + + str[len] = '\0'; + return 0; +} + static int perm_read(struct policydb *p, struct hashtab *h, void *fp) { char *key = NULL; @@ -1100,15 +1120,9 @@ static int perm_read(struct policydb *p, struct hashtab *h, void *fp) len = le32_to_cpu(buf[0]); perdatum->value = le32_to_cpu(buf[1]); - rc = -ENOMEM; - key = kmalloc(len + 1, GFP_KERNEL); - if (!key) - goto bad; - - rc = next_entry(key, fp, len); + rc = str_read(&key, GFP_KERNEL, fp, len); if (rc) goto bad; - key[len] = '\0'; rc = hashtab_insert(h, key, perdatum); if (rc) @@ -1146,15 +1160,9 @@ static int common_read(struct policydb *p, struct hashtab *h, void *fp) comdatum->permissions.nprim = le32_to_cpu(buf[2]); nel = le32_to_cpu(buf[3]); - rc = -ENOMEM; - key = kmalloc(len + 1, GFP_KERNEL); - if (!key) - goto bad; - - rc = next_entry(key, fp, len); + rc = str_read(&key, GFP_KERNEL, fp, len); if (rc) goto bad; - key[len] = '\0'; for (i = 0; i < nel; i++) { rc = perm_read(p, comdatum->permissions.table, fp); @@ -1321,25 +1329,14 @@ static int class_read(struct policydb *p, struct hashtab *h, void *fp) ncons = le32_to_cpu(buf[5]); - rc = -ENOMEM; - key = kmalloc(len + 1, GFP_KERNEL); - if (!key) - goto bad; - - rc = next_entry(key, fp, len); + rc = str_read(&key, GFP_KERNEL, fp, len); if (rc) goto bad; - key[len] = '\0'; if (len2) { - rc = -ENOMEM; - cladatum->comkey = kmalloc(len2 + 1, GFP_KERNEL); - if (!cladatum->comkey) - goto bad; - rc = next_entry(cladatum->comkey, fp, len2); + rc = str_read(&cladatum->comkey, GFP_KERNEL, fp, len2); if (rc) goto bad; - cladatum->comkey[len2] = '\0'; rc = -EINVAL; cladatum->comdatum = hashtab_search(p->p_commons.table, cladatum->comkey); @@ -1422,15 +1419,9 @@ static int role_read(struct policydb *p, struct hashtab *h, void *fp) if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) role->bounds = le32_to_cpu(buf[2]); - rc = -ENOMEM; - key = kmalloc(len + 1, GFP_KERNEL); - if (!key) - goto bad; - - rc = next_entry(key, fp, len); + rc = str_read(&key, GFP_KERNEL, fp, len); if (rc) goto bad; - key[len] = '\0'; rc = ebitmap_read(&role->dominates, fp); if (rc) @@ -1495,14 +1486,9 @@ static int type_read(struct policydb *p, struct hashtab *h, void *fp) typdatum->primary = le32_to_cpu(buf[2]); } - rc = -ENOMEM; - key = kmalloc(len + 1, GFP_KERNEL); - if (!key) - goto bad; - rc = next_entry(key, fp, len); + rc = str_read(&key, GFP_KERNEL, fp, len); if (rc) goto bad; - key[len] = '\0'; rc = hashtab_insert(h, key, typdatum); if (rc) @@ -1565,14 +1551,9 @@ static int user_read(struct policydb *p, struct hashtab *h, void *fp) if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) usrdatum->bounds = le32_to_cpu(buf[2]); - rc = -ENOMEM; - key = kmalloc(len + 1, GFP_KERNEL); - if (!key) - goto bad; - rc = next_entry(key, fp, len); + rc = str_read(&key, GFP_KERNEL, fp, len); if (rc) goto bad; - key[len] = '\0'; rc = ebitmap_read(&usrdatum->roles, fp); if (rc) @@ -1616,14 +1597,9 @@ static int sens_read(struct policydb *p, struct hashtab *h, void *fp) len = le32_to_cpu(buf[0]); levdatum->isalias = le32_to_cpu(buf[1]); - rc = -ENOMEM; - key = kmalloc(len + 1, GFP_ATOMIC); - if (!key) - goto bad; - rc = next_entry(key, fp, len); + rc = str_read(&key, GFP_ATOMIC, fp, len); if (rc) goto bad; - key[len] = '\0'; rc = -ENOMEM; levdatum->level = kmalloc(sizeof(struct mls_level), GFP_ATOMIC); @@ -1664,14 +1640,9 @@ static int cat_read(struct policydb *p, struct hashtab *h, void *fp) catdatum->value = le32_to_cpu(buf[1]); catdatum->isalias = le32_to_cpu(buf[2]); - rc = -ENOMEM; - key = kmalloc(len + 1, GFP_ATOMIC); - if (!key) - goto bad; - rc = next_entry(key, fp, len); + rc = str_read(&key, GFP_ATOMIC, fp, len); if (rc) goto bad; - key[len] = '\0'; rc = hashtab_insert(h, key, catdatum); if (rc) @@ -1968,18 +1939,12 @@ static int filename_trans_read(struct policydb *p, void *fp) goto out; len = le32_to_cpu(buf[0]); - rc = -ENOMEM; - name = kmalloc(len + 1, GFP_KERNEL); - if (!name) - goto out; - - ft->name = name; - /* path component string */ - rc = next_entry(name, fp, len); + rc = str_read(&name, GFP_KERNEL, fp, len); if (rc) goto out; - name[len] = 0; + + ft->name = name; rc = next_entry(buf, fp, sizeof(u32) * 4); if (rc) @@ -2045,17 +2010,10 @@ static int genfs_read(struct policydb *p, void *fp) if (!newgenfs) goto out; - rc = -ENOMEM; - newgenfs->fstype = kmalloc(len + 1, GFP_KERNEL); - if (!newgenfs->fstype) - goto out; - - rc = next_entry(newgenfs->fstype, fp, len); + rc = str_read(&newgenfs->fstype, GFP_KERNEL, fp, len); if (rc) goto out; - newgenfs->fstype[len] = 0; - for (genfs_p = NULL, genfs = p->genfs; genfs; genfs_p = genfs, genfs = genfs->next) { rc = -EINVAL; @@ -2091,15 +2049,9 @@ static int genfs_read(struct policydb *p, void *fp) if (!newc) goto out; - rc = -ENOMEM; - newc->u.name = kmalloc(len + 1, GFP_KERNEL); - if (!newc->u.name) - goto out; - - rc = next_entry(newc->u.name, fp, len); + rc = str_read(&newc->u.name, GFP_KERNEL, fp, len); if (rc) goto out; - newc->u.name[len] = 0; rc = next_entry(buf, fp, sizeof(u32)); if (rc) @@ -2189,16 +2141,10 @@ static int ocontext_read(struct policydb *p, struct policydb_compat_info *info, goto out; len = le32_to_cpu(buf[0]); - rc = -ENOMEM; - c->u.name = kmalloc(len + 1, GFP_KERNEL); - if (!c->u.name) - goto out; - - rc = next_entry(c->u.name, fp, len); + rc = str_read(&c->u.name, GFP_KERNEL, fp, len); if (rc) goto out; - c->u.name[len] = 0; rc = context_read_and_validate(&c->context[0], p, fp); if (rc) goto out; @@ -2240,16 +2186,11 @@ static int ocontext_read(struct policydb *p, struct policydb_compat_info *info, if (c->v.behavior > SECURITY_FS_USE_MAX) goto out; - rc = -ENOMEM; len = le32_to_cpu(buf[1]); - c->u.name = kmalloc(len + 1, GFP_KERNEL); - if (!c->u.name) - goto out; - - rc = next_entry(c->u.name, fp, len); + rc = str_read(&c->u.name, GFP_KERNEL, fp, len); if (rc) goto out; - c->u.name[len] = 0; + rc = context_read_and_validate(&c->context[0], p, fp); if (rc) goto out; @@ -2608,7 +2549,7 @@ static int mls_write_range_helper(struct mls_range *r, void *fp) if (!eq) buf[2] = cpu_to_le32(r->level[1].sens); - BUG_ON(items > (sizeof(buf)/sizeof(buf[0]))); + BUG_ON(items > ARRAY_SIZE(buf)); rc = put_entry(buf, sizeof(u32), items, fp); if (rc) @@ -2990,7 +2931,7 @@ static int role_write(void *vkey, void *datum, void *ptr) if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) buf[items++] = cpu_to_le32(role->bounds); - BUG_ON(items > (sizeof(buf)/sizeof(buf[0]))); + BUG_ON(items > ARRAY_SIZE(buf)); rc = put_entry(buf, sizeof(u32), items, fp); if (rc) @@ -3040,7 +2981,7 @@ static int type_write(void *vkey, void *datum, void *ptr) } else { buf[items++] = cpu_to_le32(typdatum->primary); } - BUG_ON(items > (sizeof(buf) / sizeof(buf[0]))); + BUG_ON(items > ARRAY_SIZE(buf)); rc = put_entry(buf, sizeof(u32), items, fp); if (rc) return rc; @@ -3069,7 +3010,7 @@ static int user_write(void *vkey, void *datum, void *ptr) buf[items++] = cpu_to_le32(usrdatum->value); if (p->policyvers >= POLICYDB_VERSION_BOUNDARY) buf[items++] = cpu_to_le32(usrdatum->bounds); - BUG_ON(items > (sizeof(buf) / sizeof(buf[0]))); + BUG_ON(items > ARRAY_SIZE(buf)); rc = put_entry(buf, sizeof(u32), items, fp); if (rc) return rc; diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 4bca49414a40..2aa9d172dc7e 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -2277,7 +2277,7 @@ out: } /** - * security_genfs_sid - Obtain a SID for a file in a filesystem + * __security_genfs_sid - Helper to obtain a SID for a file in a filesystem * @fstype: filesystem type * @path: path from root of mount * @sclass: file security class @@ -2286,11 +2286,13 @@ out: * Obtain a SID to use for a file in a filesystem that * cannot support xattr or use a fixed labeling behavior like * transition SIDs or task SIDs. + * + * The caller must acquire the policy_rwlock before calling this function. */ -int security_genfs_sid(const char *fstype, - char *path, - u16 orig_sclass, - u32 *sid) +static inline int __security_genfs_sid(const char *fstype, + char *path, + u16 orig_sclass, + u32 *sid) { int len; u16 sclass; @@ -2301,8 +2303,6 @@ int security_genfs_sid(const char *fstype, while (path[0] == '/' && path[1] == '/') path++; - read_lock(&policy_rwlock); - sclass = unmap_class(orig_sclass); *sid = SECINITSID_UNLABELED; @@ -2336,11 +2336,33 @@ int security_genfs_sid(const char *fstype, *sid = c->sid[0]; rc = 0; out: - read_unlock(&policy_rwlock); return rc; } /** + * security_genfs_sid - Obtain a SID for a file in a filesystem + * @fstype: filesystem type + * @path: path from root of mount + * @sclass: file security class + * @sid: SID for path + * + * Acquire policy_rwlock before calling __security_genfs_sid() and release + * it afterward. + */ +int security_genfs_sid(const char *fstype, + char *path, + u16 orig_sclass, + u32 *sid) +{ + int retval; + + read_lock(&policy_rwlock); + retval = __security_genfs_sid(fstype, path, orig_sclass, sid); + read_unlock(&policy_rwlock); + return retval; +} + +/** * security_fs_use - Determine how to handle labeling for a filesystem. * @sb: superblock in question */ @@ -2370,7 +2392,8 @@ int security_fs_use(struct super_block *sb) } sbsec->sid = c->sid[0]; } else { - rc = security_genfs_sid(fstype, "/", SECCLASS_DIR, &sbsec->sid); + rc = __security_genfs_sid(fstype, "/", SECCLASS_DIR, + &sbsec->sid); if (rc) { sbsec->behavior = SECURITY_FS_USE_NONE; rc = 0; |