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-rw-r--r--Documentation/sysctl/net.txt8
-rw-r--r--include/linux/filter.h1
-rw-r--r--kernel/bpf/btf.c58
-rw-r--r--kernel/bpf/core.c49
-rw-r--r--kernel/bpf/devmap.c3
-rw-r--r--kernel/bpf/helpers.c2
-rw-r--r--kernel/bpf/queue_stack_maps.c2
-rw-r--r--kernel/bpf/verifier.c13
-rw-r--r--net/core/filter.c21
-rw-r--r--net/core/sysctl_net_core.c10
-rw-r--r--tools/testing/selftests/bpf/config2
-rw-r--r--tools/testing/selftests/bpf/test_verifier.c15
12 files changed, 133 insertions, 51 deletions
diff --git a/Documentation/sysctl/net.txt b/Documentation/sysctl/net.txt
index 9ecde517728c..2793d4eac55f 100644
--- a/Documentation/sysctl/net.txt
+++ b/Documentation/sysctl/net.txt
@@ -92,6 +92,14 @@ Values :
0 - disable JIT kallsyms export (default value)
1 - enable JIT kallsyms export for privileged users only
+bpf_jit_limit
+-------------
+
+This enforces a global limit for memory allocations to the BPF JIT
+compiler in order to reject unprivileged JIT requests once it has
+been surpassed. bpf_jit_limit contains the value of the global limit
+in bytes.
+
dev_weight
--------------
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 91b4c934f02e..de629b706d1d 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -854,6 +854,7 @@ bpf_run_sk_reuseport(struct sock_reuseport *reuse, struct sock *sk,
extern int bpf_jit_enable;
extern int bpf_jit_harden;
extern int bpf_jit_kallsyms;
+extern int bpf_jit_limit;
typedef void (*bpf_jit_fill_hole_t)(void *area, unsigned int size);
diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c
index 378cef70341c..ee4c82667d65 100644
--- a/kernel/bpf/btf.c
+++ b/kernel/bpf/btf.c
@@ -2067,56 +2067,47 @@ static int btf_check_sec_info(struct btf_verifier_env *env,
return 0;
}
-static int btf_parse_hdr(struct btf_verifier_env *env, void __user *btf_data,
- u32 btf_data_size)
+static int btf_parse_hdr(struct btf_verifier_env *env)
{
+ u32 hdr_len, hdr_copy, btf_data_size;
const struct btf_header *hdr;
- u32 hdr_len, hdr_copy;
- /*
- * Minimal part of the "struct btf_header" that
- * contains the hdr_len.
- */
- struct btf_min_header {
- u16 magic;
- u8 version;
- u8 flags;
- u32 hdr_len;
- } __user *min_hdr;
struct btf *btf;
int err;
btf = env->btf;
- min_hdr = btf_data;
+ btf_data_size = btf->data_size;
- if (btf_data_size < sizeof(*min_hdr)) {
+ if (btf_data_size <
+ offsetof(struct btf_header, hdr_len) + sizeof(hdr->hdr_len)) {
btf_verifier_log(env, "hdr_len not found");
return -EINVAL;
}
- if (get_user(hdr_len, &min_hdr->hdr_len))
- return -EFAULT;
-
+ hdr = btf->data;
+ hdr_len = hdr->hdr_len;
if (btf_data_size < hdr_len) {
btf_verifier_log(env, "btf_header not found");
return -EINVAL;
}
- err = bpf_check_uarg_tail_zero(btf_data, sizeof(btf->hdr), hdr_len);
- if (err) {
- if (err == -E2BIG)
- btf_verifier_log(env, "Unsupported btf_header");
- return err;
+ /* Ensure the unsupported header fields are zero */
+ if (hdr_len > sizeof(btf->hdr)) {
+ u8 *expected_zero = btf->data + sizeof(btf->hdr);
+ u8 *end = btf->data + hdr_len;
+
+ for (; expected_zero < end; expected_zero++) {
+ if (*expected_zero) {
+ btf_verifier_log(env, "Unsupported btf_header");
+ return -E2BIG;
+ }
+ }
}
hdr_copy = min_t(u32, hdr_len, sizeof(btf->hdr));
- if (copy_from_user(&btf->hdr, btf_data, hdr_copy))
- return -EFAULT;
+ memcpy(&btf->hdr, btf->data, hdr_copy);
hdr = &btf->hdr;
- if (hdr->hdr_len != hdr_len)
- return -EINVAL;
-
btf_verifier_log_hdr(env, btf_data_size);
if (hdr->magic != BTF_MAGIC) {
@@ -2186,10 +2177,6 @@ static struct btf *btf_parse(void __user *btf_data, u32 btf_data_size,
}
env->btf = btf;
- err = btf_parse_hdr(env, btf_data, btf_data_size);
- if (err)
- goto errout;
-
data = kvmalloc(btf_data_size, GFP_KERNEL | __GFP_NOWARN);
if (!data) {
err = -ENOMEM;
@@ -2198,13 +2185,18 @@ static struct btf *btf_parse(void __user *btf_data, u32 btf_data_size,
btf->data = data;
btf->data_size = btf_data_size;
- btf->nohdr_data = btf->data + btf->hdr.hdr_len;
if (copy_from_user(data, btf_data, btf_data_size)) {
err = -EFAULT;
goto errout;
}
+ err = btf_parse_hdr(env);
+ if (err)
+ goto errout;
+
+ btf->nohdr_data = btf->data + btf->hdr.hdr_len;
+
err = btf_parse_str_sec(env);
if (err)
goto errout;
diff --git a/kernel/bpf/core.c b/kernel/bpf/core.c
index 7c7eeea8cffc..6377225b2082 100644
--- a/kernel/bpf/core.c
+++ b/kernel/bpf/core.c
@@ -365,10 +365,13 @@ void bpf_prog_kallsyms_del_all(struct bpf_prog *fp)
}
#ifdef CONFIG_BPF_JIT
+# define BPF_JIT_LIMIT_DEFAULT (PAGE_SIZE * 40000)
+
/* All BPF JIT sysctl knobs here. */
int bpf_jit_enable __read_mostly = IS_BUILTIN(CONFIG_BPF_JIT_ALWAYS_ON);
int bpf_jit_harden __read_mostly;
int bpf_jit_kallsyms __read_mostly;
+int bpf_jit_limit __read_mostly = BPF_JIT_LIMIT_DEFAULT;
static __always_inline void
bpf_get_prog_addr_region(const struct bpf_prog *prog,
@@ -577,27 +580,64 @@ int bpf_get_kallsym(unsigned int symnum, unsigned long *value, char *type,
return ret;
}
+static atomic_long_t bpf_jit_current;
+
+#if defined(MODULES_VADDR)
+static int __init bpf_jit_charge_init(void)
+{
+ /* Only used as heuristic here to derive limit. */
+ bpf_jit_limit = min_t(u64, round_up((MODULES_END - MODULES_VADDR) >> 2,
+ PAGE_SIZE), INT_MAX);
+ return 0;
+}
+pure_initcall(bpf_jit_charge_init);
+#endif
+
+static int bpf_jit_charge_modmem(u32 pages)
+{
+ if (atomic_long_add_return(pages, &bpf_jit_current) >
+ (bpf_jit_limit >> PAGE_SHIFT)) {
+ if (!capable(CAP_SYS_ADMIN)) {
+ atomic_long_sub(pages, &bpf_jit_current);
+ return -EPERM;
+ }
+ }
+
+ return 0;
+}
+
+static void bpf_jit_uncharge_modmem(u32 pages)
+{
+ atomic_long_sub(pages, &bpf_jit_current);
+}
+
struct bpf_binary_header *
bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
unsigned int alignment,
bpf_jit_fill_hole_t bpf_fill_ill_insns)
{
struct bpf_binary_header *hdr;
- unsigned int size, hole, start;
+ u32 size, hole, start, pages;
/* Most of BPF filters are really small, but if some of them
* fill a page, allow at least 128 extra bytes to insert a
* random section of illegal instructions.
*/
size = round_up(proglen + sizeof(*hdr) + 128, PAGE_SIZE);
+ pages = size / PAGE_SIZE;
+
+ if (bpf_jit_charge_modmem(pages))
+ return NULL;
hdr = module_alloc(size);
- if (hdr == NULL)
+ if (!hdr) {
+ bpf_jit_uncharge_modmem(pages);
return NULL;
+ }
/* Fill space with illegal/arch-dep instructions. */
bpf_fill_ill_insns(hdr, size);
- hdr->pages = size / PAGE_SIZE;
+ hdr->pages = pages;
hole = min_t(unsigned int, size - (proglen + sizeof(*hdr)),
PAGE_SIZE - sizeof(*hdr));
start = (get_random_int() % hole) & ~(alignment - 1);
@@ -610,7 +650,10 @@ bpf_jit_binary_alloc(unsigned int proglen, u8 **image_ptr,
void bpf_jit_binary_free(struct bpf_binary_header *hdr)
{
+ u32 pages = hdr->pages;
+
module_memfree(hdr);
+ bpf_jit_uncharge_modmem(pages);
}
/* This symbol is only overridden by archs that have different
diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c
index 141710b82a6c..191b79948424 100644
--- a/kernel/bpf/devmap.c
+++ b/kernel/bpf/devmap.c
@@ -512,8 +512,7 @@ static int dev_map_notification(struct notifier_block *notifier,
struct bpf_dtab_netdev *dev, *odev;
dev = READ_ONCE(dtab->netdev_map[i]);
- if (!dev ||
- dev->dev->ifindex != netdev->ifindex)
+ if (!dev || netdev != dev->dev)
continue;
odev = cmpxchg(&dtab->netdev_map[i], dev, NULL);
if (dev == odev)
diff --git a/kernel/bpf/helpers.c b/kernel/bpf/helpers.c
index ab0d5e3f9892..a74972b07e74 100644
--- a/kernel/bpf/helpers.c
+++ b/kernel/bpf/helpers.c
@@ -99,7 +99,6 @@ BPF_CALL_2(bpf_map_pop_elem, struct bpf_map *, map, void *, value)
const struct bpf_func_proto bpf_map_pop_elem_proto = {
.func = bpf_map_pop_elem,
.gpl_only = false,
- .pkt_access = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_CONST_MAP_PTR,
.arg2_type = ARG_PTR_TO_UNINIT_MAP_VALUE,
@@ -113,7 +112,6 @@ BPF_CALL_2(bpf_map_peek_elem, struct bpf_map *, map, void *, value)
const struct bpf_func_proto bpf_map_peek_elem_proto = {
.func = bpf_map_pop_elem,
.gpl_only = false,
- .pkt_access = true,
.ret_type = RET_INTEGER,
.arg1_type = ARG_CONST_MAP_PTR,
.arg2_type = ARG_PTR_TO_UNINIT_MAP_VALUE,
diff --git a/kernel/bpf/queue_stack_maps.c b/kernel/bpf/queue_stack_maps.c
index 12a93fb37449..8bbd72d3a121 100644
--- a/kernel/bpf/queue_stack_maps.c
+++ b/kernel/bpf/queue_stack_maps.c
@@ -122,6 +122,7 @@ static int __queue_map_get(struct bpf_map *map, void *value, bool delete)
raw_spin_lock_irqsave(&qs->lock, flags);
if (queue_stack_map_is_empty(qs)) {
+ memset(value, 0, qs->map.value_size);
err = -ENOENT;
goto out;
}
@@ -151,6 +152,7 @@ static int __stack_map_get(struct bpf_map *map, void *value, bool delete)
raw_spin_lock_irqsave(&qs->lock, flags);
if (queue_stack_map_is_empty(qs)) {
+ memset(value, 0, qs->map.value_size);
err = -ENOENT;
goto out;
}
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 98fa0be35370..171a2c88e77d 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -1387,21 +1387,24 @@ static bool may_access_direct_pkt_data(struct bpf_verifier_env *env,
enum bpf_access_type t)
{
switch (env->prog->type) {
+ /* Program types only with direct read access go here! */
case BPF_PROG_TYPE_LWT_IN:
case BPF_PROG_TYPE_LWT_OUT:
case BPF_PROG_TYPE_LWT_SEG6LOCAL:
case BPF_PROG_TYPE_SK_REUSEPORT:
- /* dst_input() and dst_output() can't write for now */
+ case BPF_PROG_TYPE_FLOW_DISSECTOR:
+ case BPF_PROG_TYPE_CGROUP_SKB:
if (t == BPF_WRITE)
return false;
/* fallthrough */
+
+ /* Program types with direct read + write access go here! */
case BPF_PROG_TYPE_SCHED_CLS:
case BPF_PROG_TYPE_SCHED_ACT:
case BPF_PROG_TYPE_XDP:
case BPF_PROG_TYPE_LWT_XMIT:
case BPF_PROG_TYPE_SK_SKB:
case BPF_PROG_TYPE_SK_MSG:
- case BPF_PROG_TYPE_FLOW_DISSECTOR:
if (meta)
return meta->pkt_access;
@@ -5706,7 +5709,11 @@ static int convert_ctx_accesses(struct bpf_verifier_env *env)
bool is_narrower_load;
u32 target_size;
- if (ops->gen_prologue) {
+ if (ops->gen_prologue || env->seen_direct_write) {
+ if (!ops->gen_prologue) {
+ verbose(env, "bpf verifier is misconfigured\n");
+ return -EINVAL;
+ }
cnt = ops->gen_prologue(insn_buf, env->seen_direct_write,
env->prog);
if (cnt >= ARRAY_SIZE(insn_buf)) {
diff --git a/net/core/filter.c b/net/core/filter.c
index 35c6933c2622..e521c5ebc7d1 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -5264,8 +5264,6 @@ sk_msg_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_msg_pull_data_proto;
case BPF_FUNC_msg_push_data:
return &bpf_msg_push_data_proto;
- case BPF_FUNC_get_local_storage:
- return &bpf_get_local_storage_proto;
default:
return bpf_base_func_proto(func_id);
}
@@ -5296,8 +5294,6 @@ sk_skb_func_proto(enum bpf_func_id func_id, const struct bpf_prog *prog)
return &bpf_sk_redirect_map_proto;
case BPF_FUNC_sk_redirect_hash:
return &bpf_sk_redirect_hash_proto;
- case BPF_FUNC_get_local_storage:
- return &bpf_get_local_storage_proto;
#ifdef CONFIG_INET
case BPF_FUNC_sk_lookup_tcp:
return &bpf_sk_lookup_tcp_proto;
@@ -5496,7 +5492,13 @@ static bool cg_skb_is_valid_access(int off, int size,
case bpf_ctx_range(struct __sk_buff, data_meta):
case bpf_ctx_range(struct __sk_buff, flow_keys):
return false;
+ case bpf_ctx_range(struct __sk_buff, data):
+ case bpf_ctx_range(struct __sk_buff, data_end):
+ if (!capable(CAP_SYS_ADMIN))
+ return false;
+ break;
}
+
if (type == BPF_WRITE) {
switch (off) {
case bpf_ctx_range(struct __sk_buff, mark):
@@ -5638,6 +5640,15 @@ static bool sock_filter_is_valid_access(int off, int size,
prog->expected_attach_type);
}
+static int bpf_noop_prologue(struct bpf_insn *insn_buf, bool direct_write,
+ const struct bpf_prog *prog)
+{
+ /* Neither direct read nor direct write requires any preliminary
+ * action.
+ */
+ return 0;
+}
+
static int bpf_unclone_prologue(struct bpf_insn *insn_buf, bool direct_write,
const struct bpf_prog *prog, int drop_verdict)
{
@@ -7204,6 +7215,7 @@ const struct bpf_verifier_ops xdp_verifier_ops = {
.get_func_proto = xdp_func_proto,
.is_valid_access = xdp_is_valid_access,
.convert_ctx_access = xdp_convert_ctx_access,
+ .gen_prologue = bpf_noop_prologue,
};
const struct bpf_prog_ops xdp_prog_ops = {
@@ -7302,6 +7314,7 @@ const struct bpf_verifier_ops sk_msg_verifier_ops = {
.get_func_proto = sk_msg_func_proto,
.is_valid_access = sk_msg_is_valid_access,
.convert_ctx_access = sk_msg_convert_ctx_access,
+ .gen_prologue = bpf_noop_prologue,
};
const struct bpf_prog_ops sk_msg_prog_ops = {
diff --git a/net/core/sysctl_net_core.c b/net/core/sysctl_net_core.c
index b1a2c5e38530..37b4667128a3 100644
--- a/net/core/sysctl_net_core.c
+++ b/net/core/sysctl_net_core.c
@@ -279,7 +279,6 @@ static int proc_dointvec_minmax_bpf_enable(struct ctl_table *table, int write,
return ret;
}
-# ifdef CONFIG_HAVE_EBPF_JIT
static int
proc_dointvec_minmax_bpf_restricted(struct ctl_table *table, int write,
void __user *buffer, size_t *lenp,
@@ -290,7 +289,6 @@ proc_dointvec_minmax_bpf_restricted(struct ctl_table *table, int write,
return proc_dointvec_minmax(table, write, buffer, lenp, ppos);
}
-# endif
#endif
static struct ctl_table net_core_table[] = {
@@ -397,6 +395,14 @@ static struct ctl_table net_core_table[] = {
.extra2 = &one,
},
# endif
+ {
+ .procname = "bpf_jit_limit",
+ .data = &bpf_jit_limit,
+ .maxlen = sizeof(int),
+ .mode = 0600,
+ .proc_handler = proc_dointvec_minmax_bpf_restricted,
+ .extra1 = &one,
+ },
#endif
{
.procname = "netdev_tstamp_prequeue",
diff --git a/tools/testing/selftests/bpf/config b/tools/testing/selftests/bpf/config
index dd49df5e2df4..7f90d3645af8 100644
--- a/tools/testing/selftests/bpf/config
+++ b/tools/testing/selftests/bpf/config
@@ -20,3 +20,5 @@ CONFIG_VXLAN=y
CONFIG_GENEVE=y
CONFIG_NET_CLS_FLOWER=m
CONFIG_LWTUNNEL=y
+CONFIG_BPF_STREAM_PARSER=y
+CONFIG_XDP_SOCKETS=y
diff --git a/tools/testing/selftests/bpf/test_verifier.c b/tools/testing/selftests/bpf/test_verifier.c
index 769d68a48f30..36f3d3009d1a 100644
--- a/tools/testing/selftests/bpf/test_verifier.c
+++ b/tools/testing/selftests/bpf/test_verifier.c
@@ -4891,6 +4891,8 @@ static struct bpf_test tests[] = {
BPF_EXIT_INSN(),
},
.result = ACCEPT,
+ .result_unpriv = REJECT,
+ .errstr_unpriv = "invalid bpf_context access off=76 size=4",
.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
},
{
@@ -5146,6 +5148,7 @@ static struct bpf_test tests[] = {
.fixup_cgroup_storage = { 1 },
.result = REJECT,
.errstr = "get_local_storage() doesn't support non-zero flags",
+ .errstr_unpriv = "R2 leaks addr into helper function",
.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
},
{
@@ -5261,6 +5264,7 @@ static struct bpf_test tests[] = {
.fixup_percpu_cgroup_storage = { 1 },
.result = REJECT,
.errstr = "get_local_storage() doesn't support non-zero flags",
+ .errstr_unpriv = "R2 leaks addr into helper function",
.prog_type = BPF_PROG_TYPE_CGROUP_SKB,
},
{
@@ -14050,6 +14054,13 @@ static void get_unpriv_disabled()
fclose(fd);
}
+static bool test_as_unpriv(struct bpf_test *test)
+{
+ return !test->prog_type ||
+ test->prog_type == BPF_PROG_TYPE_SOCKET_FILTER ||
+ test->prog_type == BPF_PROG_TYPE_CGROUP_SKB;
+}
+
static int do_test(bool unpriv, unsigned int from, unsigned int to)
{
int i, passes = 0, errors = 0, skips = 0;
@@ -14060,10 +14071,10 @@ static int do_test(bool unpriv, unsigned int from, unsigned int to)
/* Program types that are not supported by non-root we
* skip right away.
*/
- if (!test->prog_type && unpriv_disabled) {
+ if (test_as_unpriv(test) && unpriv_disabled) {
printf("#%d/u %s SKIP\n", i, test->descr);
skips++;
- } else if (!test->prog_type) {
+ } else if (test_as_unpriv(test)) {
if (!unpriv)
set_admin(false);
printf("#%d/u %s ", i, test->descr);
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-24 04:39:06 +0000