diff options
| -rw-r--r-- | security/apparmor/domain.c | 26 | ||||
| -rw-r--r-- | security/apparmor/file.c | 24 | ||||
| -rw-r--r-- | security/apparmor/include/path.h | 49 | ||||
| -rw-r--r-- | security/apparmor/lsm.c | 111 | ||||
| -rw-r--r-- | security/apparmor/mount.c | 65 |
5 files changed, 164 insertions, 111 deletions
diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c index ca2dccf5b445..cae0e619ff4f 100644 --- a/security/apparmor/domain.c +++ b/security/apparmor/domain.c @@ -689,20 +689,9 @@ static struct aa_label *profile_transition(struct aa_profile *profile, } else if (COMPLAIN_MODE(profile)) { /* no exec permission - learning mode */ struct aa_profile *new_profile = NULL; - char *n = kstrdup(name, GFP_ATOMIC); - - if (n) { - /* name is ptr into buffer */ - long pos = name - buffer; - /* break per cpu buffer hold */ - put_buffers(buffer); - new_profile = aa_new_null_profile(profile, false, n, - GFP_KERNEL); - get_buffers(buffer); - name = buffer + pos; - strcpy((char *)name, n); - kfree(n); - } + + new_profile = aa_new_null_profile(profile, false, name, + GFP_KERNEL); if (!new_profile) { error = -ENOMEM; info = "could not create null profile"; @@ -907,7 +896,12 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm) ctx->nnp = aa_get_label(label); /* buffer freed below, name is pointer into buffer */ - get_buffers(buffer); + buffer = aa_get_buffer(); + if (!buffer) { + error = -ENOMEM; + goto done; + } + /* Test for onexec first as onexec override other x transitions. */ if (ctx->onexec) new = handle_onexec(label, ctx->onexec, ctx->token, @@ -979,7 +973,7 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm) done: aa_put_label(label); - put_buffers(buffer); + aa_put_buffer(buffer); return error; diff --git a/security/apparmor/file.c b/security/apparmor/file.c index d0afed9ebd0e..7b424e73a8c7 100644 --- a/security/apparmor/file.c +++ b/security/apparmor/file.c @@ -336,12 +336,14 @@ int aa_path_perm(const char *op, struct aa_label *label, flags |= PATH_DELEGATE_DELETED | (S_ISDIR(cond->mode) ? PATH_IS_DIR : 0); - get_buffers(buffer); + buffer = aa_get_buffer(); + if (!buffer) + return -ENOMEM; error = fn_for_each_confined(label, profile, profile_path_perm(op, profile, path, buffer, request, cond, flags, &perms)); - put_buffers(buffer); + aa_put_buffer(buffer); return error; } @@ -479,12 +481,18 @@ int aa_path_link(struct aa_label *label, struct dentry *old_dentry, int error; /* buffer freed below, lname is pointer in buffer */ - get_buffers(buffer, buffer2); + buffer = aa_get_buffer(); + buffer2 = aa_get_buffer(); + error = -ENOMEM; + if (!buffer || !buffer2) + goto out; + error = fn_for_each_confined(label, profile, profile_path_link(profile, &link, buffer, &target, buffer2, &cond)); - put_buffers(buffer, buffer2); - +out: + aa_put_buffer(buffer); + aa_put_buffer(buffer2); return error; } @@ -528,7 +536,9 @@ static int __file_path_perm(const char *op, struct aa_label *label, return 0; flags = PATH_DELEGATE_DELETED | (S_ISDIR(cond.mode) ? PATH_IS_DIR : 0); - get_buffers(buffer); + buffer = aa_get_buffer(); + if (!buffer) + return -ENOMEM; /* check every profile in task label not in current cache */ error = fn_for_each_not_in_set(flabel, label, profile, @@ -557,7 +567,7 @@ static int __file_path_perm(const char *op, struct aa_label *label, if (!error) update_file_ctx(file_ctx(file), label, request); - put_buffers(buffer); + aa_put_buffer(buffer); return error; } diff --git a/security/apparmor/include/path.h b/security/apparmor/include/path.h index b6380c5f0097..b0b2ab85e42d 100644 --- a/security/apparmor/include/path.h +++ b/security/apparmor/include/path.h @@ -15,7 +15,6 @@ #ifndef __AA_PATH_H #define __AA_PATH_H - enum path_flags { PATH_IS_DIR = 0x1, /* path is a directory */ PATH_CONNECT_PATH = 0x4, /* connect disconnected paths to / */ @@ -30,51 +29,7 @@ int aa_path_name(const struct path *path, int flags, char *buffer, const char **name, const char **info, const char *disconnected); -#define MAX_PATH_BUFFERS 2 - -/* Per cpu buffers used during mediation */ -/* preallocated buffers to use during path lookups */ -struct aa_buffers { - char *buf[MAX_PATH_BUFFERS]; -}; - -#include <linux/percpu.h> -#include <linux/preempt.h> - -DECLARE_PER_CPU(struct aa_buffers, aa_buffers); - -#define ASSIGN(FN, A, X, N) ((X) = FN(A, N)) -#define EVAL1(FN, A, X) ASSIGN(FN, A, X, 0) /*X = FN(0)*/ -#define EVAL2(FN, A, X, Y...) \ - do { ASSIGN(FN, A, X, 1); EVAL1(FN, A, Y); } while (0) -#define EVAL(FN, A, X...) CONCATENATE(EVAL, COUNT_ARGS(X))(FN, A, X) - -#define for_each_cpu_buffer(I) for ((I) = 0; (I) < MAX_PATH_BUFFERS; (I)++) - -#ifdef CONFIG_DEBUG_PREEMPT -#define AA_BUG_PREEMPT_ENABLED(X) AA_BUG(preempt_count() <= 0, X) -#else -#define AA_BUG_PREEMPT_ENABLED(X) /* nop */ -#endif - -#define __get_buffer(C, N) ({ \ - AA_BUG_PREEMPT_ENABLED("__get_buffer without preempt disabled"); \ - (C)->buf[(N)]; }) - -#define __get_buffers(C, X...) EVAL(__get_buffer, C, X) - -#define __put_buffers(X, Y...) ((void)&(X)) - -#define get_buffers(X...) \ -do { \ - struct aa_buffers *__cpu_var = get_cpu_ptr(&aa_buffers); \ - __get_buffers(__cpu_var, X); \ -} while (0) - -#define put_buffers(X, Y...) \ -do { \ - __put_buffers(X, Y); \ - put_cpu_ptr(&aa_buffers); \ -} while (0) +char *aa_get_buffer(void); +void aa_put_buffer(char *buf); #endif /* __AA_PATH_H */ diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index 8f7ffc51ad86..3e0cfdebee45 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -48,8 +48,13 @@ /* Flag indicating whether initialization completed */ int apparmor_initialized; -DEFINE_PER_CPU(struct aa_buffers, aa_buffers); +union aa_buffer { + struct list_head list; + char buffer[1]; +}; +static LIST_HEAD(aa_global_buffers); +static DEFINE_SPINLOCK(aa_buffers_lock); /* * LSM hook functions @@ -1422,6 +1427,7 @@ static int param_set_aauint(const char *val, const struct kernel_param *kp) return -EPERM; error = param_set_uint(val, kp); + aa_g_path_max = max_t(uint32_t, aa_g_path_max, sizeof(union aa_buffer)); pr_info("AppArmor: buffer size set to %d bytes\n", aa_g_path_max); return error; @@ -1565,6 +1571,48 @@ static int param_set_mode(const char *val, const struct kernel_param *kp) return 0; } +char *aa_get_buffer(void) +{ + union aa_buffer *aa_buf; + bool try_again = true; + +retry: + spin_lock(&aa_buffers_lock); + if (!list_empty(&aa_global_buffers)) { + aa_buf = list_first_entry(&aa_global_buffers, union aa_buffer, + list); + list_del(&aa_buf->list); + spin_unlock(&aa_buffers_lock); + return &aa_buf->buffer[0]; + } + spin_unlock(&aa_buffers_lock); + + aa_buf = kmalloc(aa_g_path_max, GFP_KERNEL | __GFP_RETRY_MAYFAIL | + __GFP_NOWARN); + if (!aa_buf) { + if (try_again) { + try_again = false; + goto retry; + } + pr_warn_once("AppArmor: Failed to allocate a memory buffer.\n"); + return NULL; + } + return &aa_buf->buffer[0]; +} + +void aa_put_buffer(char *buf) +{ + union aa_buffer *aa_buf; + + if (!buf) + return; + aa_buf = container_of(buf, union aa_buffer, buffer[0]); + + spin_lock(&aa_buffers_lock); + list_add(&aa_buf->list, &aa_global_buffers); + spin_unlock(&aa_buffers_lock); +} + /* * AppArmor init functions */ @@ -1585,38 +1633,48 @@ static int __init set_init_ctx(void) static void destroy_buffers(void) { - u32 i, j; + union aa_buffer *aa_buf; - for_each_possible_cpu(i) { - for_each_cpu_buffer(j) { - kfree(per_cpu(aa_buffers, i).buf[j]); - per_cpu(aa_buffers, i).buf[j] = NULL; - } + spin_lock(&aa_buffers_lock); + while (!list_empty(&aa_global_buffers)) { + aa_buf = list_first_entry(&aa_global_buffers, union aa_buffer, + list); + list_del(&aa_buf->list); + spin_unlock(&aa_buffers_lock); + kfree(aa_buf); + spin_lock(&aa_buffers_lock); } + spin_unlock(&aa_buffers_lock); } static int __init alloc_buffers(void) { - u32 i, j; - - for_each_possible_cpu(i) { - for_each_cpu_buffer(j) { - char *buffer; - - if (cpu_to_node(i) > num_online_nodes()) - /* fallback to kmalloc for offline nodes */ - buffer = kmalloc(aa_g_path_max, GFP_KERNEL); - else - buffer = kmalloc_node(aa_g_path_max, GFP_KERNEL, - cpu_to_node(i)); - if (!buffer) { - destroy_buffers(); - return -ENOMEM; - } - per_cpu(aa_buffers, i).buf[j] = buffer; + union aa_buffer *aa_buf; + int i, num; + + /* + * A function may require two buffers at once. Usually the buffers are + * used for a short period of time and are shared. On UP kernel buffers + * two should be enough, with more CPUs it is possible that more + * buffers will be used simultaneously. The preallocated pool may grow. + * This preallocation has also the side-effect that AppArmor will be + * disabled early at boot if aa_g_path_max is extremly high. + */ + if (num_online_cpus() > 1) + num = 4; + else + num = 2; + + for (i = 0; i < num; i++) { + + aa_buf = kmalloc(aa_g_path_max, GFP_KERNEL | + __GFP_RETRY_MAYFAIL | __GFP_NOWARN); + if (!aa_buf) { + destroy_buffers(); + return -ENOMEM; } + aa_put_buffer(&aa_buf->buffer[0]); } - return 0; } @@ -1781,7 +1839,7 @@ static int __init apparmor_init(void) error = alloc_buffers(); if (error) { AA_ERROR("Unable to allocate work buffers\n"); - goto buffers_out; + goto alloc_out; } error = set_init_ctx(); @@ -1806,7 +1864,6 @@ static int __init apparmor_init(void) buffers_out: destroy_buffers(); - alloc_out: aa_destroy_aafs(); aa_teardown_dfa_engine(); diff --git a/security/apparmor/mount.c b/security/apparmor/mount.c index 8c3787399356..267a26fba14e 100644 --- a/security/apparmor/mount.c +++ b/security/apparmor/mount.c @@ -412,11 +412,13 @@ int aa_remount(struct aa_label *label, const struct path *path, binary = path->dentry->d_sb->s_type->fs_flags & FS_BINARY_MOUNTDATA; - get_buffers(buffer); + buffer = aa_get_buffer(); + if (!buffer) + return -ENOMEM; error = fn_for_each_confined(label, profile, match_mnt(profile, path, buffer, NULL, NULL, NULL, flags, data, binary)); - put_buffers(buffer); + aa_put_buffer(buffer); return error; } @@ -441,11 +443,18 @@ int aa_bind_mount(struct aa_label *label, const struct path *path, if (error) return error; - get_buffers(buffer, old_buffer); + buffer = aa_get_buffer(); + old_buffer = aa_get_buffer(); + error = -ENOMEM; + if (!buffer || old_buffer) + goto out; + error = fn_for_each_confined(label, profile, match_mnt(profile, path, buffer, &old_path, old_buffer, NULL, flags, NULL, false)); - put_buffers(buffer, old_buffer); +out: + aa_put_buffer(buffer); + aa_put_buffer(old_buffer); path_put(&old_path); return error; @@ -465,11 +474,13 @@ int aa_mount_change_type(struct aa_label *label, const struct path *path, flags &= (MS_REC | MS_SILENT | MS_SHARED | MS_PRIVATE | MS_SLAVE | MS_UNBINDABLE); - get_buffers(buffer); + buffer = aa_get_buffer(); + if (!buffer) + return -ENOMEM; error = fn_for_each_confined(label, profile, match_mnt(profile, path, buffer, NULL, NULL, NULL, flags, NULL, false)); - put_buffers(buffer); + aa_put_buffer(buffer); return error; } @@ -492,11 +503,17 @@ int aa_move_mount(struct aa_label *label, const struct path *path, if (error) return error; - get_buffers(buffer, old_buffer); + buffer = aa_get_buffer(); + old_buffer = aa_get_buffer(); + error = -ENOMEM; + if (!buffer || !old_buffer) + goto out; error = fn_for_each_confined(label, profile, match_mnt(profile, path, buffer, &old_path, old_buffer, NULL, MS_MOVE, NULL, false)); - put_buffers(buffer, old_buffer); +out: + aa_put_buffer(buffer); + aa_put_buffer(old_buffer); path_put(&old_path); return error; @@ -537,17 +554,29 @@ int aa_new_mount(struct aa_label *label, const char *dev_name, } } - get_buffers(buffer, dev_buffer); + buffer = aa_get_buffer(); + if (!buffer) { + error = -ENOMEM; + goto out; + } if (dev_path) { error = fn_for_each_confined(label, profile, match_mnt(profile, path, buffer, dev_path, dev_buffer, type, flags, data, binary)); } else { + dev_buffer = aa_get_buffer(); + if (!dev_buffer) { + error = -ENOMEM; + goto out; + } error = fn_for_each_confined(label, profile, match_mnt_path_str(profile, path, buffer, dev_name, type, flags, data, binary, NULL)); } - put_buffers(buffer, dev_buffer); + +out: + aa_put_buffer(buffer); + aa_put_buffer(dev_buffer); if (dev_path) path_put(dev_path); @@ -595,10 +624,13 @@ int aa_umount(struct aa_label *label, struct vfsmount *mnt, int flags) AA_BUG(!label); AA_BUG(!mnt); - get_buffers(buffer); + buffer = aa_get_buffer(); + if (!buffer) + return -ENOMEM; + error = fn_for_each_confined(label, profile, profile_umount(profile, &path, buffer)); - put_buffers(buffer); + aa_put_buffer(buffer); return error; } @@ -671,7 +703,11 @@ int aa_pivotroot(struct aa_label *label, const struct path *old_path, AA_BUG(!old_path); AA_BUG(!new_path); - get_buffers(old_buffer, new_buffer); + old_buffer = aa_get_buffer(); + new_buffer = aa_get_buffer(); + error = -ENOMEM; + if (!old_buffer || !new_buffer) + goto out; target = fn_label_build(label, profile, GFP_ATOMIC, build_pivotroot(profile, new_path, new_buffer, old_path, old_buffer)); @@ -690,7 +726,8 @@ int aa_pivotroot(struct aa_label *label, const struct path *old_path, /* already audited error */ error = PTR_ERR(target); out: - put_buffers(old_buffer, new_buffer); + aa_put_buffer(old_buffer); + aa_put_buffer(new_buffer); return error; |