diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-12-03 12:51:35 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-12-03 12:51:35 -0800 |
commit | 79e178a57dae819ae724065b47c25720494cc9f2 (patch) | |
tree | 821bf3adee5ad86ba88d2ed25f2131854aa10147 | |
parent | 01d1dff64662646023482806c6db8ef0b280c403 (diff) | |
parent | 341c1fda5e17156619fb71acfc7082b2669b4b72 (diff) | |
download | lwn-79e178a57dae819ae724065b47c25720494cc9f2.tar.gz lwn-79e178a57dae819ae724065b47c25720494cc9f2.zip |
Merge tag 'apparmor-pr-2019-12-03' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor
Pull apparmor updates from John Johansen:
"Features:
- increase left match history buffer size to provide improved
conflict resolution in overlapping execution rules.
- switch buffer allocation to use a memory pool and GFP_KERNEL where
possible.
- add compression of policy blobs to reduce memory usage.
Cleanups:
- fix spelling mistake "immutible" -> "immutable"
Bug fixes:
- fix unsigned len comparison in update_for_len macro
- fix sparse warning for type-casting of current->real_cred"
* tag 'apparmor-pr-2019-12-03' of git://git.kernel.org/pub/scm/linux/kernel/git/jj/linux-apparmor:
apparmor: make it so work buffers can be allocated from atomic context
apparmor: reduce rcu_read_lock scope for aa_file_perm mediation
apparmor: fix wrong buffer allocation in aa_new_mount
apparmor: fix unsigned len comparison with less than zero
apparmor: increase left match history buffer size
apparmor: Switch to GFP_KERNEL where possible
apparmor: Use a memory pool instead per-CPU caches
apparmor: Force type-casting of current->real_cred
apparmor: fix spelling mistake "immutible" -> "immutable"
apparmor: fix blob compression when ns is forced on a policy load
apparmor: fix missing ZLIB defines
apparmor: fix blob compression build failure on ppc
apparmor: Initial implementation of raw policy blob compression
-rw-r--r-- | security/apparmor/Kconfig | 2 | ||||
-rw-r--r-- | security/apparmor/apparmorfs.c | 130 | ||||
-rw-r--r-- | security/apparmor/domain.c | 46 | ||||
-rw-r--r-- | security/apparmor/file.c | 45 | ||||
-rw-r--r-- | security/apparmor/include/apparmor.h | 1 | ||||
-rw-r--r-- | security/apparmor/include/file.h | 2 | ||||
-rw-r--r-- | security/apparmor/include/match.h | 3 | ||||
-rw-r--r-- | security/apparmor/include/path.h | 50 | ||||
-rw-r--r-- | security/apparmor/include/policy_unpack.h | 8 | ||||
-rw-r--r-- | security/apparmor/label.c | 12 | ||||
-rw-r--r-- | security/apparmor/lsm.c | 198 | ||||
-rw-r--r-- | security/apparmor/match.c | 6 | ||||
-rw-r--r-- | security/apparmor/mount.c | 67 | ||||
-rw-r--r-- | security/apparmor/policy.c | 5 | ||||
-rw-r--r-- | security/apparmor/policy_unpack.c | 116 |
15 files changed, 526 insertions, 165 deletions
diff --git a/security/apparmor/Kconfig b/security/apparmor/Kconfig index d8b1a360a636..a422a349f926 100644 --- a/security/apparmor/Kconfig +++ b/security/apparmor/Kconfig @@ -6,6 +6,8 @@ config SECURITY_APPARMOR select SECURITY_PATH select SECURITYFS select SECURITY_NETWORK + select ZLIB_INFLATE + select ZLIB_DEFLATE default n help This enables the AppArmor security module. diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c index 45d13b6462aa..09996f2552ee 100644 --- a/security/apparmor/apparmorfs.c +++ b/security/apparmor/apparmorfs.c @@ -21,6 +21,7 @@ #include <linux/fs.h> #include <linux/fs_context.h> #include <linux/poll.h> +#include <linux/zlib.h> #include <uapi/linux/major.h> #include <uapi/linux/magic.h> @@ -65,6 +66,35 @@ * support fns */ +struct rawdata_f_data { + struct aa_loaddata *loaddata; +}; + +#define RAWDATA_F_DATA_BUF(p) (char *)(p + 1) + +static void rawdata_f_data_free(struct rawdata_f_data *private) +{ + if (!private) + return; + + aa_put_loaddata(private->loaddata); + kvfree(private); +} + +static struct rawdata_f_data *rawdata_f_data_alloc(size_t size) +{ + struct rawdata_f_data *ret; + + if (size > SIZE_MAX - sizeof(*ret)) + return ERR_PTR(-EINVAL); + + ret = kvzalloc(sizeof(*ret) + size, GFP_KERNEL); + if (!ret) + return ERR_PTR(-ENOMEM); + + return ret; +} + /** * aa_mangle_name - mangle a profile name to std profile layout form * @name: profile name to mangle (NOT NULL) @@ -1280,36 +1310,117 @@ static int seq_rawdata_hash_show(struct seq_file *seq, void *v) return 0; } +static int seq_rawdata_compressed_size_show(struct seq_file *seq, void *v) +{ + struct aa_loaddata *data = seq->private; + + seq_printf(seq, "%zu\n", data->compressed_size); + + return 0; +} + SEQ_RAWDATA_FOPS(abi); SEQ_RAWDATA_FOPS(revision); SEQ_RAWDATA_FOPS(hash); +SEQ_RAWDATA_FOPS(compressed_size); + +static int deflate_decompress(char *src, size_t slen, char *dst, size_t dlen) +{ + int error; + struct z_stream_s strm; + + if (aa_g_rawdata_compression_level == 0) { + if (dlen < slen) + return -EINVAL; + memcpy(dst, src, slen); + return 0; + } + + memset(&strm, 0, sizeof(strm)); + + strm.workspace = kvzalloc(zlib_inflate_workspacesize(), GFP_KERNEL); + if (!strm.workspace) + return -ENOMEM; + + strm.next_in = src; + strm.avail_in = slen; + + error = zlib_inflateInit(&strm); + if (error != Z_OK) { + error = -ENOMEM; + goto fail_inflate_init; + } + + strm.next_out = dst; + strm.avail_out = dlen; + + error = zlib_inflate(&strm, Z_FINISH); + if (error != Z_STREAM_END) + error = -EINVAL; + else + error = 0; + + zlib_inflateEnd(&strm); +fail_inflate_init: + kvfree(strm.workspace); + return error; +} static ssize_t rawdata_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) { - struct aa_loaddata *rawdata = file->private_data; + struct rawdata_f_data *private = file->private_data; - return simple_read_from_buffer(buf, size, ppos, rawdata->data, - rawdata->size); + return simple_read_from_buffer(buf, size, ppos, + RAWDATA_F_DATA_BUF(private), + private->loaddata->size); } static int rawdata_release(struct inode *inode, struct file *file) { - aa_put_loaddata(file->private_data); + rawdata_f_data_free(file->private_data); return 0; } static int rawdata_open(struct inode *inode, struct file *file) { + int error; + struct aa_loaddata *loaddata; + struct rawdata_f_data *private; + if (!policy_view_capable(NULL)) return -EACCES; - file->private_data = __aa_get_loaddata(inode->i_private); - if (!file->private_data) + + loaddata = __aa_get_loaddata(inode->i_private); + if (!loaddata) /* lost race: this entry is being reaped */ return -ENOENT; + private = rawdata_f_data_alloc(loaddata->size); + if (IS_ERR(private)) { + error = PTR_ERR(private); + goto fail_private_alloc; + } + + private->loaddata = loaddata; + + error = deflate_decompress(loaddata->data, loaddata->compressed_size, + RAWDATA_F_DATA_BUF(private), + loaddata->size); + if (error) + goto fail_decompress; + + file->private_data = private; return 0; + +fail_decompress: + rawdata_f_data_free(private); + return error; + +fail_private_alloc: + aa_put_loaddata(loaddata); + return error; } static const struct file_operations rawdata_fops = { @@ -1388,6 +1499,13 @@ int __aa_fs_create_rawdata(struct aa_ns *ns, struct aa_loaddata *rawdata) rawdata->dents[AAFS_LOADDATA_HASH] = dent; } + dent = aafs_create_file("compressed_size", S_IFREG | 0444, dir, + rawdata, + &seq_rawdata_compressed_size_fops); + if (IS_ERR(dent)) + goto fail; + rawdata->dents[AAFS_LOADDATA_COMPRESSED_SIZE] = dent; + dent = aafs_create_file("raw_data", S_IFREG | 0444, dir, rawdata, &rawdata_fops); if (IS_ERR(dent)) diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c index 9e0492795267..9be7ccb8379e 100644 --- a/security/apparmor/domain.c +++ b/security/apparmor/domain.c @@ -520,7 +520,7 @@ struct aa_label *x_table_lookup(struct aa_profile *profile, u32 xindex, label = &new_profile->label; continue; } - label = aa_label_parse(&profile->label, *name, GFP_ATOMIC, + label = aa_label_parse(&profile->label, *name, GFP_KERNEL, true, false); if (IS_ERR(label)) label = NULL; @@ -600,7 +600,7 @@ static struct aa_label *x_to_label(struct aa_profile *profile, /* base the stack on post domain transition */ struct aa_label *base = new; - new = aa_label_parse(base, stack, GFP_ATOMIC, true, false); + new = aa_label_parse(base, stack, GFP_KERNEL, true, false); if (IS_ERR(new)) new = NULL; aa_put_label(base); @@ -685,20 +685,9 @@ 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"; @@ -719,7 +708,7 @@ static struct aa_label *profile_transition(struct aa_profile *profile, if (DEBUG_ON) { dbg_printk("apparmor: scrubbing environment variables" " for %s profile=", name); - aa_label_printk(new, GFP_ATOMIC); + aa_label_printk(new, GFP_KERNEL); dbg_printk("\n"); } *secure_exec = true; @@ -795,7 +784,7 @@ static int profile_onexec(struct aa_profile *profile, struct aa_label *onexec, if (DEBUG_ON) { dbg_printk("apparmor: scrubbing environment " "variables for %s label=", xname); - aa_label_printk(onexec, GFP_ATOMIC); + aa_label_printk(onexec, GFP_KERNEL); dbg_printk("\n"); } *secure_exec = true; @@ -829,7 +818,7 @@ static struct aa_label *handle_onexec(struct aa_label *label, bprm, buffer, cond, unsafe)); if (error) return ERR_PTR(error); - new = fn_label_build_in_ns(label, profile, GFP_ATOMIC, + new = fn_label_build_in_ns(label, profile, GFP_KERNEL, aa_get_newest_label(onexec), profile_transition(profile, bprm, buffer, cond, unsafe)); @@ -841,9 +830,9 @@ static struct aa_label *handle_onexec(struct aa_label *label, buffer, cond, unsafe)); if (error) return ERR_PTR(error); - new = fn_label_build_in_ns(label, profile, GFP_ATOMIC, + new = fn_label_build_in_ns(label, profile, GFP_KERNEL, aa_label_merge(&profile->label, onexec, - GFP_ATOMIC), + GFP_KERNEL), profile_transition(profile, bprm, buffer, cond, unsafe)); } @@ -903,13 +892,18 @@ 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(false); + 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, bprm, buffer, &cond, &unsafe); else - new = fn_label_build(label, profile, GFP_ATOMIC, + new = fn_label_build(label, profile, GFP_KERNEL, profile_transition(profile, bprm, buffer, &cond, &unsafe)); @@ -953,7 +947,7 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm) if (DEBUG_ON) { dbg_printk("scrubbing environment variables for %s " "label=", bprm->filename); - aa_label_printk(new, GFP_ATOMIC); + aa_label_printk(new, GFP_KERNEL); dbg_printk("\n"); } bprm->secureexec = 1; @@ -964,7 +958,7 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm) if (DEBUG_ON) { dbg_printk("apparmor: clearing unsafe personality " "bits. %s label=", bprm->filename); - aa_label_printk(new, GFP_ATOMIC); + aa_label_printk(new, GFP_KERNEL); dbg_printk("\n"); } bprm->per_clear |= PER_CLEAR_ON_SETID; @@ -975,7 +969,7 @@ 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 4c1b05eb130c..fe2ebe5e865e 100644 --- a/security/apparmor/file.c +++ b/security/apparmor/file.c @@ -76,7 +76,7 @@ static void file_audit_cb(struct audit_buffer *ab, void *va) if (aad(sa)->peer) { audit_log_format(ab, " target="); aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer, - FLAG_VIEW_SUBNS, GFP_ATOMIC); + FLAG_VIEW_SUBNS, GFP_KERNEL); } else if (aad(sa)->fs.target) { audit_log_format(ab, " target="); audit_log_untrustedstring(ab, aad(sa)->fs.target); @@ -332,12 +332,14 @@ 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(false); + 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; } @@ -475,12 +477,18 @@ 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(false); + buffer2 = aa_get_buffer(false); + 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; } @@ -507,7 +515,7 @@ static void update_file_ctx(struct aa_file_ctx *fctx, struct aa_label *label, static int __file_path_perm(const char *op, struct aa_label *label, struct aa_label *flabel, struct file *file, - u32 request, u32 denied) + u32 request, u32 denied, bool in_atomic) { struct aa_profile *profile; struct aa_perms perms = {}; @@ -524,7 +532,9 @@ 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(in_atomic); + if (!buffer) + return -ENOMEM; /* check every profile in task label not in current cache */ error = fn_for_each_not_in_set(flabel, label, profile, @@ -553,7 +563,7 @@ 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; } @@ -590,11 +600,12 @@ static int __file_sock_perm(const char *op, struct aa_label *label, * @label: label being enforced (NOT NULL) * @file: file to revalidate access permissions on (NOT NULL) * @request: requested permissions + * @in_atomic: whether allocations need to be done in atomic context * * Returns: %0 if access allowed else error */ int aa_file_perm(const char *op, struct aa_label *label, struct file *file, - u32 request) + u32 request, bool in_atomic) { struct aa_file_ctx *fctx; struct aa_label *flabel; @@ -607,7 +618,8 @@ int aa_file_perm(const char *op, struct aa_label *label, struct file *file, fctx = file_ctx(file); rcu_read_lock(); - flabel = rcu_dereference(fctx->label); + flabel = aa_get_newest_label(rcu_dereference(fctx->label)); + rcu_read_unlock(); AA_BUG(!flabel); /* revalidate access, if task is unconfined, or the cached cred @@ -626,14 +638,13 @@ int aa_file_perm(const char *op, struct aa_label *label, struct file *file, if (file->f_path.mnt && path_mediated_fs(file->f_path.dentry)) error = __file_path_perm(op, label, flabel, file, request, - denied); + denied, in_atomic); else if (S_ISSOCK(file_inode(file)->i_mode)) error = __file_sock_perm(op, label, flabel, file, request, denied); done: - rcu_read_unlock(); - + aa_put_label(flabel); return error; } @@ -655,7 +666,8 @@ static void revalidate_tty(struct aa_label *label) struct tty_file_private, list); file = file_priv->file; - if (aa_file_perm(OP_INHERIT, label, file, MAY_READ | MAY_WRITE)) + if (aa_file_perm(OP_INHERIT, label, file, MAY_READ | MAY_WRITE, + IN_ATOMIC)) drop_tty = 1; } spin_unlock(&tty->files_lock); @@ -669,7 +681,8 @@ static int match_file(const void *p, struct file *file, unsigned int fd) { struct aa_label *label = (struct aa_label *)p; - if (aa_file_perm(OP_INHERIT, label, file, aa_map_file_to_perms(file))) + if (aa_file_perm(OP_INHERIT, label, file, aa_map_file_to_perms(file), + IN_ATOMIC)) return fd + 1; return 0; } diff --git a/security/apparmor/include/apparmor.h b/security/apparmor/include/apparmor.h index 6b7e6e13176e..1fbabdb565a8 100644 --- a/security/apparmor/include/apparmor.h +++ b/security/apparmor/include/apparmor.h @@ -36,6 +36,7 @@ extern enum audit_mode aa_g_audit; extern bool aa_g_audit_header; extern bool aa_g_debug; extern bool aa_g_hash_policy; +extern int aa_g_rawdata_compression_level; extern bool aa_g_lock_policy; extern bool aa_g_logsyscall; extern bool aa_g_paranoid_load; diff --git a/security/apparmor/include/file.h b/security/apparmor/include/file.h index a852be89a7dc..aff26fc71407 100644 --- a/security/apparmor/include/file.h +++ b/security/apparmor/include/file.h @@ -197,7 +197,7 @@ int aa_path_link(struct aa_label *label, struct dentry *old_dentry, const struct path *new_dir, struct dentry *new_dentry); int aa_file_perm(const char *op, struct aa_label *label, struct file *file, - u32 request); + u32 request, bool in_atomic); void aa_inherit_files(const struct cred *cred, struct files_struct *files); diff --git a/security/apparmor/include/match.h b/security/apparmor/include/match.h index 6b0af638a18d..e23f4aadc1ff 100644 --- a/security/apparmor/include/match.h +++ b/security/apparmor/include/match.h @@ -134,7 +134,7 @@ unsigned int aa_dfa_matchn_until(struct aa_dfa *dfa, unsigned int start, void aa_dfa_free_kref(struct kref *kref); -#define WB_HISTORY_SIZE 8 +#define WB_HISTORY_SIZE 24 struct match_workbuf { unsigned int count; unsigned int pos; @@ -147,7 +147,6 @@ struct match_workbuf N = { \ .count = 0, \ .pos = 0, \ .len = 0, \ - .size = WB_HISTORY_SIZE, \ } unsigned int aa_dfa_leftmatch(struct aa_dfa *dfa, unsigned int start, diff --git a/security/apparmor/include/path.h b/security/apparmor/include/path.h index 35a8295e8f3a..44a7945fbe3c 100644 --- a/security/apparmor/include/path.h +++ b/security/apparmor/include/path.h @@ -11,7 +11,6 @@ #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 / */ @@ -26,51 +25,8 @@ 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) +#define IN_ATOMIC true +char *aa_get_buffer(bool in_atomic); +void aa_put_buffer(char *buf); #endif /* __AA_PATH_H */ diff --git a/security/apparmor/include/policy_unpack.h b/security/apparmor/include/policy_unpack.h index 46aefae918f5..e0e1ca7ebc38 100644 --- a/security/apparmor/include/policy_unpack.h +++ b/security/apparmor/include/policy_unpack.h @@ -41,6 +41,7 @@ enum { AAFS_LOADDATA_REVISION, AAFS_LOADDATA_HASH, AAFS_LOADDATA_DATA, + AAFS_LOADDATA_COMPRESSED_SIZE, AAFS_LOADDATA_DIR, /* must be last actual entry */ AAFS_LOADDATA_NDENTS /* count of entries */ }; @@ -61,11 +62,16 @@ struct aa_loaddata { struct dentry *dents[AAFS_LOADDATA_NDENTS]; struct aa_ns *ns; char *name; - size_t size; + size_t size; /* the original size of the payload */ + size_t compressed_size; /* the compressed size of the payload */ long revision; /* the ns policy revision this caused */ int abi; unsigned char *hash; + /* Pointer to payload. If @compressed_size > 0, then this is the + * compressed version of the payload, else it is the uncompressed + * version (with the size indicated by @size). + */ char *data; }; diff --git a/security/apparmor/label.c b/security/apparmor/label.c index 59f1cc2557a7..470693239e64 100644 --- a/security/apparmor/label.c +++ b/security/apparmor/label.c @@ -1458,11 +1458,13 @@ static inline bool use_label_hname(struct aa_ns *ns, struct aa_label *label, /* helper macro for snprint routines */ #define update_for_len(total, len, size, str) \ do { \ + size_t ulen = len; \ + \ AA_BUG(len < 0); \ - total += len; \ - len = min(len, size); \ - size -= len; \ - str += len; \ + total += ulen; \ + ulen = min(ulen, size); \ + size -= ulen; \ + str += ulen; \ } while (0) /** @@ -1597,7 +1599,7 @@ int aa_label_snxprint(char *str, size_t size, struct aa_ns *ns, struct aa_ns *prev_ns = NULL; struct label_it i; int count = 0, total = 0; - size_t len; + ssize_t len; AA_BUG(!str && size != 0); AA_BUG(!label); diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index ec3a928af829..b621ad74f54a 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -21,6 +21,7 @@ #include <linux/user_namespace.h> #include <linux/netfilter_ipv4.h> #include <linux/netfilter_ipv6.h> +#include <linux/zlib.h> #include <net/sock.h> #include <uapi/linux/mount.h> @@ -43,8 +44,17 @@ /* 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]; +}; + +#define RESERVE_COUNT 2 +static int reserve_count = RESERVE_COUNT; +static int buffer_count; +static LIST_HEAD(aa_global_buffers); +static DEFINE_SPINLOCK(aa_buffers_lock); /* * LSM hook functions @@ -442,7 +452,8 @@ static void apparmor_file_free_security(struct file *file) aa_put_label(rcu_access_pointer(ctx->label)); } -static int common_file_perm(const char *op, struct file *file, u32 mask) +static int common_file_perm(const char *op, struct file *file, u32 mask, + bool in_atomic) { struct aa_label *label; int error = 0; @@ -452,7 +463,7 @@ static int common_file_perm(const char *op, struct file *file, u32 mask) return -EACCES; label = __begin_current_label_crit_section(); - error = aa_file_perm(op, label, file, mask); + error = aa_file_perm(op, label, file, mask, in_atomic); __end_current_label_crit_section(label); return error; @@ -460,12 +471,13 @@ static int common_file_perm(const char *op, struct file *file, u32 mask) static int apparmor_file_receive(struct file *file) { - return common_file_perm(OP_FRECEIVE, file, aa_map_file_to_perms(file)); + return common_file_perm(OP_FRECEIVE, file, aa_map_file_to_perms(file), + false); } static int apparmor_file_permission(struct file *file, int mask) { - return common_file_perm(OP_FPERM, file, mask); + return common_file_perm(OP_FPERM, file, mask, false); } static int apparmor_file_lock(struct file *file, unsigned int cmd) @@ -475,11 +487,11 @@ static int apparmor_file_lock(struct file *file, unsigned int cmd) if (cmd == F_WRLCK) mask |= MAY_WRITE; - return common_file_perm(OP_FLOCK, file, mask); + return common_file_perm(OP_FLOCK, file, mask, false); } static int common_mmap(const char *op, struct file *file, unsigned long prot, - unsigned long flags) + unsigned long flags, bool in_atomic) { int mask = 0; @@ -497,20 +509,21 @@ static int common_mmap(const char *op, struct file *file, unsigned long prot, if (prot & PROT_EXEC) mask |= AA_EXEC_MMAP; - return common_file_perm(op, file, mask); + return common_file_perm(op, file, mask, in_atomic); } static int apparmor_mmap_file(struct file *file, unsigned long reqprot, unsigned long prot, unsigned long flags) { - return common_mmap(OP_FMMAP, file, prot, flags); + return common_mmap(OP_FMMAP, file, prot, flags, GFP_ATOMIC); } static int apparmor_file_mprotect(struct vm_area_struct *vma, unsigned long reqprot, unsigned long prot) { return common_mmap(OP_FMPROT, vma->vm_file, prot, - !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0); + !(vma->vm_flags & VM_SHARED) ? MAP_PRIVATE : 0, + false); } static int apparmor_sb_mount(const char *dev_name, const struct path *path, @@ -1262,6 +1275,16 @@ static const struct kernel_param_ops param_ops_aauint = { .get = param_get_aauint }; +static int param_set_aacompressionlevel(const char *val, + const struct kernel_param *kp); +static int param_get_aacompressionlevel(char *buffer, + const struct kernel_param *kp); +#define param_check_aacompressionlevel param_check_int +static const struct kernel_param_ops param_ops_aacompressionlevel = { + .set = param_set_aacompressionlevel, + .get = param_get_aacompressionlevel +}; + static int param_set_aalockpolicy(const char *val, const struct kernel_param *kp); static int param_get_aalockpolicy(char *buffer, const struct kernel_param *kp); #define param_check_aalockpolicy param_check_bool @@ -1292,6 +1315,11 @@ bool aa_g_hash_policy = IS_ENABLED(CONFIG_SECURITY_APPARMOR_HASH_DEFAULT); module_param_named(hash_policy, aa_g_hash_policy, aabool, S_IRUSR | S_IWUSR); #endif +/* policy loaddata compression level */ +int aa_g_rawdata_compression_level = Z_DEFAULT_COMPRESSION; +module_param_named(rawdata_compression_level, aa_g_rawdata_compression_level, + aacompressionlevel, 0400); + /* Debug mode */ bool aa_g_debug = IS_ENABLED(CONFIG_SECURITY_APPARMOR_DEBUG_MESSAGES); module_param_named(debug, aa_g_debug, aabool, S_IRUSR | S_IWUSR); @@ -1402,6 +1430,7 @@ 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; @@ -1456,6 +1485,37 @@ static int param_get_aaintbool(char *buffer, const struct kernel_param *kp) return param_get_bool(buffer, &kp_local); } +static int param_set_aacompressionlevel(const char *val, + const struct kernel_param *kp) +{ + int error; + + if (!apparmor_enabled) + return -EINVAL; + if (apparmor_initialized) + return -EPERM; + + error = param_set_int(val, kp); + + aa_g_rawdata_compression_level = clamp(aa_g_rawdata_compression_level, + Z_NO_COMPRESSION, + Z_BEST_COMPRESSION); + pr_info("AppArmor: policy rawdata compression level set to %u\n", + aa_g_rawdata_compression_level); + + return error; +} + +static int param_get_aacompressionlevel(char *buffer, + const struct kernel_param *kp) +{ + if (!apparmor_enabled) + return -EINVAL; + if (apparmor_initialized && !policy_view_capable(NULL)) + return -EPERM; + return param_get_int(buffer, kp); +} + static int param_get_audit(char *buffer, const struct kernel_param *kp) { if (!apparmor_enabled) @@ -1514,6 +1574,61 @@ static int param_set_mode(const char *val, const struct kernel_param *kp) return 0; } +char *aa_get_buffer(bool in_atomic) +{ + union aa_buffer *aa_buf; + bool try_again = true; + gfp_t flags = (GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_NOWARN); + +retry: + spin_lock(&aa_buffers_lock); + if (buffer_count > reserve_count || + (in_atomic && !list_empty(&aa_global_buffers))) { + aa_buf = list_first_entry(&aa_global_buffers, union aa_buffer, + list); + list_del(&aa_buf->list); + buffer_count--; + spin_unlock(&aa_buffers_lock); + return &aa_buf->buffer[0]; + } + if (in_atomic) { + /* + * out of reserve buffers and in atomic context so increase + * how many buffers to keep in reserve + */ + reserve_count++; + flags = GFP_ATOMIC; + } + spin_unlock(&aa_buffers_lock); + + if (!in_atomic) + might_sleep(); + aa_buf = kmalloc(aa_g_path_max, flags); + 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); + buffer_count++; + spin_unlock(&aa_buffers_lock); +} + /* * AppArmor init functions */ @@ -1525,7 +1640,7 @@ static int param_set_mode(const char *val, const struct kernel_param *kp) */ static int __init set_init_ctx(void) { - struct cred *cred = (struct cred *)current->real_cred; + struct cred *cred = (__force struct cred *)current->real_cred; set_cred_label(cred, aa_get_label(ns_unconfined(root_ns))); @@ -1534,38 +1649,48 @@ 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 + RESERVE_COUNT; + else + num = 2 + RESERVE_COUNT; + + 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; } @@ -1730,7 +1855,7 @@ 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(); @@ -1755,7 +1880,6 @@ static int __init apparmor_init(void) buffers_out: destroy_buffers(); - alloc_out: aa_destroy_aafs(); aa_teardown_dfa_engine(); diff --git a/security/apparmor/match.c b/security/apparmor/match.c index 6ccd3734a841..525ce22dc0e9 100644 --- a/security/apparmor/match.c +++ b/security/apparmor/match.c @@ -616,8 +616,8 @@ unsigned int aa_dfa_matchn_until(struct aa_dfa *dfa, unsigned int start, #define inc_wb_pos(wb) \ do { \ - wb->pos = (wb->pos + 1) & (wb->size - 1); \ - wb->len = (wb->len + 1) & (wb->size - 1); \ + wb->pos = (wb->pos + 1) & (WB_HISTORY_SIZE - 1); \ + wb->len = (wb->len + 1) & (WB_HISTORY_SIZE - 1); \ } while (0) /* For DFAs that don't support extended tagging of states */ @@ -636,7 +636,7 @@ static bool is_loop(struct match_workbuf *wb, unsigned int state, return true; } if (pos == 0) - pos = wb->size; + pos = WB_HISTORY_SIZE; pos--; } diff --git a/security/apparmor/mount.c b/security/apparmor/mount.c index 17081c8dbefa..4ed6688f9d40 100644 --- a/security/apparmor/mount.c +++ b/security/apparmor/mount.c @@ -408,11 +408,13 @@ 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(false); + 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; } @@ -437,11 +439,18 @@ 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(false); + old_buffer = aa_get_buffer(false); + 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; @@ -461,11 +470,13 @@ 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(false); + 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; } @@ -488,11 +499,17 @@ 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(false); + old_buffer = aa_get_buffer(false); + 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; @@ -533,8 +550,17 @@ int aa_new_mount(struct aa_label *label, const char *dev_name, } } - get_buffers(buffer, dev_buffer); + buffer = aa_get_buffer(false); + if (!buffer) { + error = -ENOMEM; + goto out; + } if (dev_path) { + dev_buffer = aa_get_buffer(false); + if (!dev_buffer) { + error = -ENOMEM; + goto out; + } error = fn_for_each_confined(label, profile, match_mnt(profile, path, buffer, dev_path, dev_buffer, type, flags, data, binary)); @@ -543,7 +569,10 @@ int aa_new_mount(struct aa_label *label, const char *dev_name, 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); @@ -591,10 +620,13 @@ 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(false); + 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; } @@ -667,8 +699,12 @@ 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); - target = fn_label_build(label, profile, GFP_ATOMIC, + old_buffer = aa_get_buffer(false); + new_buffer = aa_get_buffer(false); + error = -ENOMEM; + if (!old_buffer || !new_buffer) + goto out; + target = fn_label_build(label, profile, GFP_KERNEL, build_pivotroot(profile, new_path, new_buffer, old_path, old_buffer)); if (!target) { @@ -686,7 +722,8 @@ 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; diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c index ade333074c8e..03104830c913 100644 --- a/security/apparmor/policy.c +++ b/security/apparmor/policy.c @@ -582,7 +582,7 @@ static int replacement_allowed(struct aa_profile *profile, int noreplace, { if (profile) { if (profile->label.flags & FLAG_IMMUTIBLE) { - *info = "cannot replace immutible profile"; + *info = "cannot replace immutable profile"; return -EPERM; } else if (noreplace) { *info = "profile already exists"; @@ -856,7 +856,7 @@ static struct aa_profile *update_to_newest_parent(struct aa_profile *new) ssize_t aa_replace_profiles(struct aa_ns *policy_ns, struct aa_label *label, u32 mask, struct aa_loaddata *udata) { - const char *ns_name, *info = NULL; + const char *ns_name = NULL, *info = NULL; struct aa_ns *ns = NULL; struct aa_load_ent *ent, *tmp; struct aa_loaddata *rawdata_ent; @@ -1043,6 +1043,7 @@ ssize_t aa_replace_profiles(struct aa_ns *policy_ns, struct aa_label *label, out: aa_put_ns(ns); aa_put_loaddata(udata); + kfree(ns_name); if (error) return error; diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c index 8cfc9493eefc..80364310fb1e 100644 --- a/security/apparmor/policy_unpack.c +++ b/security/apparmor/policy_unpack.c @@ -16,6 +16,7 @@ #include <asm/unaligned.h> #include <linux/ctype.h> #include <linux/errno.h> +#include <linux/zlib.h> #include "include/apparmor.h" #include "include/audit.h" @@ -139,9 +140,11 @@ bool aa_rawdata_eq(struct aa_loaddata *l, struct aa_loaddata *r) { if (l->size != r->size) return false; + if (l->compressed_size != r->compressed_size) + return false; if (aa_g_hash_policy && memcmp(l->hash, r->hash, aa_hash_size()) != 0) return false; - return memcmp(l->data, r->data, r->size) == 0; + return memcmp(l->data, r->data, r->compressed_size ?: r->size) == 0; } /* @@ -968,11 +971,14 @@ static int verify_header(struct aa_ext *e, int required, const char **ns) e, error); return error; } - if (*ns && strcmp(*ns, name)) + if (*ns && strcmp(*ns, name)) { audit_iface(NULL, NULL, NULL, "invalid ns change", e, error); - else if (!*ns) - *ns = name; + } else if (!*ns) { + *ns = kstrdup(name, GFP_KERNEL); + if (!*ns) + return -ENOMEM; + } } return 0; @@ -1039,6 +1045,105 @@ struct aa_load_ent *aa_load_ent_alloc(void) return ent; } +static int deflate_compress(const char *src, size_t slen, char **dst, + size_t *dlen) +{ + int error; + struct z_stream_s strm; + void *stgbuf, *dstbuf; + size_t stglen = deflateBound(slen); + + memset(&strm, 0, sizeof(strm)); + + if (stglen < slen) + return -EFBIG; + + strm.workspace = kvzalloc(zlib_deflate_workspacesize(MAX_WBITS, + MAX_MEM_LEVEL), + GFP_KERNEL); + if (!strm.workspace) + return -ENOMEM; + + error = zlib_deflateInit(&strm, aa_g_rawdata_compression_level); + if (error != Z_OK) { + error = -ENOMEM; + goto fail_deflate_init; + } + + stgbuf = kvzalloc(stglen, GFP_KERNEL); + if (!stgbuf) { + error = -ENOMEM; + goto fail_stg_alloc; + } + + strm.next_in = src; + strm.avail_in = slen; + strm.next_out = stgbuf; + strm.avail_out = stglen; + + error = zlib_deflate(&strm, Z_FINISH); + if (error != Z_STREAM_END) { + error = -EINVAL; + goto fail_deflate; + } + error = 0; + + if (is_vmalloc_addr(stgbuf)) { + dstbuf = kvzalloc(strm.total_out, GFP_KERNEL); + if (dstbuf) { + memcpy(dstbuf, stgbuf, strm.total_out); + kvfree(stgbuf); + } + } else + /* + * If the staging buffer was kmalloc'd, then using krealloc is + * probably going to be faster. The destination buffer will + * always be smaller, so it's just shrunk, avoiding a memcpy + */ + dstbuf = krealloc(stgbuf, strm.total_out, GFP_KERNEL); + + if (!dstbuf) { + error = -ENOMEM; + goto fail_deflate; + } + + *dst = dstbuf; + *dlen = strm.total_out; + +fail_stg_alloc: + zlib_deflateEnd(&strm); +fail_deflate_init: + kvfree(strm.workspace); + return error; + +fail_deflate: + kvfree(stgbuf); + goto fail_stg_alloc; +} + +static int compress_loaddata(struct aa_loaddata *data) +{ + + AA_BUG(data->compressed_size > 0); + + /* + * Shortcut the no compression case, else we increase the amount of + * storage required by a small amount + */ + if (aa_g_rawdata_compression_level != 0) { + void *udata = data->data; + int error = deflate_compress(udata, data->size, &data->data, + &data->compressed_size); + if (error) + return error; + + kvfree(udata); + } else + data->compressed_size = data->size; + + return 0; +} + /** * aa_unpack - unpack packed binary profile(s) data loaded from user space * @udata: user data copied to kmem (NOT NULL) @@ -1107,6 +1212,9 @@ int aa_unpack(struct aa_loaddata *udata, struct list_head *lh, goto fail; } } + error = compress_loaddata(udata); + if (error) + goto fail; return 0; fail_profile: |