Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says: ==================== bpf 2023-01-16 We've added 6 non-merge commits during the last 8 day(s) which contain a total of 6 files changed, 22 insertions(+), 24 deletions(-). The main changes are: 1) Mitigate a Spectre v4 leak in unprivileged BPF from speculative pointer-as-scalar type confusion, from Luis Gerhorst. 2) Fix a splat when pid 1 attaches a BPF program that attempts to send killing signal to itself, from Hao Sun. 3) Fix BPF program ID information in BPF_AUDIT_UNLOAD as well as PERF_BPF_EVENT_PROG_UNLOAD events, from Paul Moore. 4) Fix BPF verifier warning triggered from invalid kfunc call in backtrack_insn, also from Hao Sun. 5) Fix potential deadlock in htab_lock_bucket from same bucket index but different map_locked index, from Tonghao Zhang. * tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: bpf: Fix pointer-leak due to insufficient speculative store bypass mitigation bpf: hash map, avoid deadlock with suitable hash mask bpf: remove the do_idr_lock parameter from bpf_prog_free_id() bpf: restore the ebpf program ID for BPF_AUDIT_UNLOAD and PERF_BPF_EVENT_PROG_UNLOAD bpf: Skip task with pid=1 in send_signal_common() bpf: Skip invalid kfunc call in backtrack_insn ====================

Jakub Kicinski committed 3 years ago

Commit 423c1d32 parents 441717b e4f4db46 files · +22 −24Browse files

Unified · Split

6 files

include/linux/bpf.h +1 −1
kernel/bpf/hashtab.c +2 −2
kernel/bpf/offload.c +0 −3
kernel/bpf/syscall.c +7 −17
kernel/bpf/verifier.c +9 −1
kernel/trace/bpf_trace.c +3 −0

include/linux/bpf.h+1−1

@@ -1832,7 +1832,7 @@ void bpf_prog_inc(struct bpf_prog *prog); · 1831 unmodified lines
1832	1832	struct bpf_prog * __must_check bpf_prog_inc_not_zero(struct bpf_prog *prog);
1833	1833	void bpf_prog_put(struct bpf_prog *prog);
1834	1834
1835		−void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock);
	1835	+void bpf_prog_free_id(struct bpf_prog *prog);
1836	1836	void bpf_map_free_id(struct bpf_map *map, bool do_idr_lock);
1837	1837
1838	1838	struct btf_field btf_record_find(const struct btf_record rec,

kernel/bpf/hashtab.c+2−2

@@ -152,7 +152,7 @@ static inline int htab_lock_bucket(const struct bpf_htab *htab, · 151 unmodified lines
152	152	{
153	153	unsigned long flags;
154	154
155		− hash = hash & HASHTAB_MAP_LOCK_MASK;
	155	+ hash = hash & min_t(u32, HASHTAB_MAP_LOCK_MASK, htab->n_buckets - 1);
156	156
157	157	preempt_disable();
158	158	if (unlikely(__this_cpu_inc_return(*(htab->map_locked[hash])) != 1)) {
@@ -171,7 +171,7 @@ static inline void htab_unlock_bucket(const struct bpf_htab *htab, · 12 unmodified lines
171	171	struct bucket *b, u32 hash,
172	172	unsigned long flags)
173	173	{
174		− hash = hash & HASHTAB_MAP_LOCK_MASK;
	174	+ hash = hash & min_t(u32, HASHTAB_MAP_LOCK_MASK, htab->n_buckets - 1);
175	175	raw_spin_unlock_irqrestore(&b->raw_lock, flags);
176	176	__this_cpu_dec(*(htab->map_locked[hash]));
177	177	preempt_enable();

kernel/bpf/offload.c+0−3

@@ -216,9 +216,6 @@ static void __bpf_prog_offload_destroy(struct bpf_prog *prog) · 215 unmodified lines
216	216	if (offload->dev_state)
217	217	offload->offdev->ops->destroy(prog);
218	218
219		− /* Make sure BPF_PROG_GET_NEXT_ID can't find this dead program */
220		− bpf_prog_free_id(prog, true);
221		−
222	219	list_del_init(&offload->offloads);
223	220	kfree(offload);
224	221	prog->aux->offload = NULL;

kernel/bpf/syscall.c+7−17

@@ -1972,7 +1972,7 @@ static void bpf_audit_prog(const struct bpf_prog *prog, unsigned int op) · 1971 unmodified lines
1972	1972	return;
1973	1973	if (audit_enabled == AUDIT_OFF)
1974	1974	return;
1975		− if (op == BPF_AUDIT_LOAD)
	1975	+ if (!in_irq() && !irqs_disabled())
1976	1976	ctx = audit_context();
1977	1977	ab = audit_log_start(ctx, GFP_ATOMIC, AUDIT_BPF);
1978	1978	if (unlikely(!ab))
@@ -2001,7 +2001,7 @@ static int bpf_prog_alloc_id(struct bpf_prog *prog) · 22 unmodified lines
2001	2001	return id > 0 ? 0 : id;
2002	2002	}
2003	2003
2004		−void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock)
	2004	+void bpf_prog_free_id(struct bpf_prog *prog)
2005	2005	{
2006	2006	unsigned long flags;
2007	2007
@@ -2013,18 +2013,10 @@ void bpf_prog_free_id(struct bpf_prog *prog, bool do_idr_lock) · 5 unmodified lines
2013	2013	if (!prog->aux->id)
2014	2014	return;
2015	2015
2016		− if (do_idr_lock)
2017		− spin_lock_irqsave(&prog_idr_lock, flags);
2018		− else
2019		− __acquire(&prog_idr_lock);
2020		−
	2016	+ spin_lock_irqsave(&prog_idr_lock, flags);
2021	2017	idr_remove(&prog_idr, prog->aux->id);
2022	2018	prog->aux->id = 0;
2023		−
2024		− if (do_idr_lock)
2025		− spin_unlock_irqrestore(&prog_idr_lock, flags);
2026		− else
2027		− __release(&prog_idr_lock);
	2019	+ spin_unlock_irqrestore(&prog_idr_lock, flags);
2028	2020	}
2029	2021
2030	2022	static void __bpf_prog_put_rcu(struct rcu_head *rcu)
@@ -2067,17 +2059,15 @@ static void bpf_prog_put_deferred(struct work_struct *work) · 36 unmodified lines
2067	2059	prog = aux->prog;
2068	2060	perf_event_bpf_event(prog, PERF_BPF_EVENT_PROG_UNLOAD, 0);
2069	2061	bpf_audit_prog(prog, BPF_AUDIT_UNLOAD);
	2062	+ bpf_prog_free_id(prog);
2070	2063	__bpf_prog_put_noref(prog, true);
2071	2064	}
2072	2065
2073		−static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock)
	2066	+static void __bpf_prog_put(struct bpf_prog *prog)
2074	2067	{
2075	2068	struct bpf_prog_aux *aux = prog->aux;
2076	2069
2077	2070	if (atomic64_dec_and_test(&aux->refcnt)) {
2078		− /* bpf_prog_free_id() must be called first */
2079		− bpf_prog_free_id(prog, do_idr_lock);
2080		−
2081	2071	if (in_irq() \|\| irqs_disabled()) {
2082	2072	INIT_WORK(&aux->work, bpf_prog_put_deferred);
2083	2073	schedule_work(&aux->work);
@@ -2089,7 +2079,7 @@ static void __bpf_prog_put(struct bpf_prog *prog, bool do_idr_lock) · 5 unmodified lines
2089	2079
2090	2080	void bpf_prog_put(struct bpf_prog *prog)
2091	2081	{
2092		− __bpf_prog_put(prog, true);
	2082	+ __bpf_prog_put(prog);
2093	2083	}
2094	2084	EXPORT_SYMBOL_GPL(bpf_prog_put);
2095	2085

kernel/bpf/verifier.c+9−1

@@ -2748,6 +2748,12 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, · 2747 unmodified lines
2748	2748	*/
2749	2749	if (insn->src_reg == 0 && is_callback_calling_function(insn->imm))
2750	2750	return -ENOTSUPP;
	2751	+ /* kfunc with imm==0 is invalid and fixup_kfunc_call will
	2752	+ * catch this error later. Make backtracking conservative
	2753	+ * with ENOTSUPP.
	2754	+ */
	2755	+ if (insn->src_reg == BPF_PSEUDO_KFUNC_CALL && insn->imm == 0)
	2756	+ return -ENOTSUPP;
2751	2757	/* regular helper call sets R0 */
2752	2758	*reg_mask &= ~1;
2753	2759	if (*reg_mask & 0x3f) {
@@ -3289,7 +3295,9 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env, · 535 unmodified lines
3289	3295	bool sanitize = reg && is_spillable_regtype(reg->type);
3290	3296
3291	3297	for (i = 0; i < size; i++) {
3292		− if (state->stack[spi].slot_type[i] == STACK_INVALID) {
	3298	+ u8 type = state->stack[spi].slot_type[i];
	3299	+
	3300	+ if (type != STACK_MISC && type != STACK_ZERO) {
3293	3301	sanitize = true;
3294	3302	break;
3295	3303	}

kernel/trace/bpf_trace.c+3−0

@@ -848,6 +848,9 @@ static int bpf_send_signal_common(u32 sig, enum pid_type type) · 847 unmodified lines
848	848	return -EPERM;
849	849	if (unlikely(!nmi_uaccess_okay()))
850	850	return -EPERM;
	851	+ /* Task should not be pid=1 to avoid kernel panic. */
	852	+ if (unlikely(is_global_init(current)))
	853	+ return -EPERM;
851	854
852	855	if (irqs_disabled()) {
853	856	/* Do an early check on signal validity. Otherwise,