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authorLinus Torvalds <torvalds@linux-foundation.org>2025-09-30 17:58:11 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2025-09-30 17:58:11 -0700
commitae28ed4578e6d5a481e39c5a9827f27048661fdd (patch)
treefd29a311fe5f4ab052c4973fca50bca55e82bf94 /kernel/bpf/verifier.c
parent4b81e2eb9e4db8f6094c077d0c8b27c264901c1b (diff)
parent4ef77dd584cfd915526328f516fec59e3a54d66e (diff)
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Merge tag 'bpf-next-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Pull bpf updates from Alexei Starovoitov: - Support pulling non-linear xdp data with bpf_xdp_pull_data() kfunc (Amery Hung) Applied as a stable branch in bpf-next and net-next trees. - Support reading skb metadata via bpf_dynptr (Jakub Sitnicki) Also a stable branch in bpf-next and net-next trees. - Enforce expected_attach_type for tailcall compatibility (Daniel Borkmann) - Replace path-sensitive with path-insensitive live stack analysis in the verifier (Eduard Zingerman) This is a significant change in the verification logic. More details, motivation, long term plans are in the cover letter/merge commit. - Support signed BPF programs (KP Singh) This is another major feature that took years to materialize. Algorithm details are in the cover letter/marge commit - Add support for may_goto instruction to s390 JIT (Ilya Leoshkevich) - Add support for may_goto instruction to arm64 JIT (Puranjay Mohan) - Fix USDT SIB argument handling in libbpf (Jiawei Zhao) - Allow uprobe-bpf program to change context registers (Jiri Olsa) - Support signed loads from BPF arena (Kumar Kartikeya Dwivedi and Puranjay Mohan) - Allow access to union arguments in tracing programs (Leon Hwang) - Optimize rcu_read_lock() + migrate_disable() combination where it's used in BPF subsystem (Menglong Dong) - Introduce bpf_task_work_schedule*() kfuncs to schedule deferred execution of BPF callback in the context of a specific task using the kernel’s task_work infrastructure (Mykyta Yatsenko) - Enforce RCU protection for KF_RCU_PROTECTED kfuncs (Kumar Kartikeya Dwivedi) - Add stress test for rqspinlock in NMI (Kumar Kartikeya Dwivedi) - Improve the precision of tnum multiplier verifier operation (Nandakumar Edamana) - Use tnums to improve is_branch_taken() logic (Paul Chaignon) - Add support for atomic operations in arena in riscv JIT (Pu Lehui) - Report arena faults to BPF error stream (Puranjay Mohan) - Search for tracefs at /sys/kernel/tracing first in bpftool (Quentin Monnet) - Add bpf_strcasecmp() kfunc (Rong Tao) - Support lookup_and_delete_elem command in BPF_MAP_STACK_TRACE (Tao Chen) * tag 'bpf-next-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (197 commits) libbpf: Replace AF_ALG with open coded SHA-256 selftests/bpf: Add stress test for rqspinlock in NMI selftests/bpf: Add test case for different expected_attach_type bpf: Enforce expected_attach_type for tailcall compatibility bpftool: Remove duplicate string.h header bpf: Remove duplicate crypto/sha2.h header libbpf: Fix error when st-prefix_ops and ops from differ btf selftests/bpf: Test changing packet data from kfunc selftests/bpf: Add stacktrace map lookup_and_delete_elem test case selftests/bpf: Refactor stacktrace_map case with skeleton bpf: Add lookup_and_delete_elem for BPF_MAP_STACK_TRACE selftests/bpf: Fix flaky bpf_cookie selftest selftests/bpf: Test changing packet data from global functions with a kfunc bpf: Emit struct bpf_xdp_sock type in vmlinux BTF selftests/bpf: Task_work selftest cleanup fixes MAINTAINERS: Delete inactive maintainers from AF_XDP bpf: Mark kfuncs as __noclone selftests/bpf: Add kprobe multi write ctx attach test selftests/bpf: Add kprobe write ctx attach test selftests/bpf: Add uprobe context ip register change test ...
Diffstat (limited to 'kernel/bpf/verifier.c')
-rw-r--r--kernel/bpf/verifier.c869
1 files changed, 404 insertions, 465 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index 8340cecd1b35..73bba397672a 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c
@@ -674,6 +674,8 @@ static enum bpf_dynptr_type arg_to_dynptr_type(enum bpf_arg_type arg_type)
return BPF_DYNPTR_TYPE_SKB;
case DYNPTR_TYPE_XDP:
return BPF_DYNPTR_TYPE_XDP;
+ case DYNPTR_TYPE_SKB_META:
+ return BPF_DYNPTR_TYPE_SKB_META;
default:
return BPF_DYNPTR_TYPE_INVALID;
}
@@ -690,6 +692,8 @@ static enum bpf_type_flag get_dynptr_type_flag(enum bpf_dynptr_type type)
return DYNPTR_TYPE_SKB;
case BPF_DYNPTR_TYPE_XDP:
return DYNPTR_TYPE_XDP;
+ case BPF_DYNPTR_TYPE_SKB_META:
+ return DYNPTR_TYPE_SKB_META;
default:
return 0;
}
@@ -783,8 +787,7 @@ static int mark_stack_slots_dynptr(struct bpf_verifier_env *env, struct bpf_reg_
state->stack[spi - 1].spilled_ptr.ref_obj_id = id;
}
- state->stack[spi].spilled_ptr.live |= REG_LIVE_WRITTEN;
- state->stack[spi - 1].spilled_ptr.live |= REG_LIVE_WRITTEN;
+ bpf_mark_stack_write(env, state->frameno, BIT(spi - 1) | BIT(spi));
return 0;
}
@@ -801,29 +804,7 @@ static void invalidate_dynptr(struct bpf_verifier_env *env, struct bpf_func_stat
__mark_reg_not_init(env, &state->stack[spi].spilled_ptr);
__mark_reg_not_init(env, &state->stack[spi - 1].spilled_ptr);
- /* Why do we need to set REG_LIVE_WRITTEN for STACK_INVALID slot?
- *
- * While we don't allow reading STACK_INVALID, it is still possible to
- * do <8 byte writes marking some but not all slots as STACK_MISC. Then,
- * helpers or insns can do partial read of that part without failing,
- * but check_stack_range_initialized, check_stack_read_var_off, and
- * check_stack_read_fixed_off will do mark_reg_read for all 8-bytes of
- * the slot conservatively. Hence we need to prevent those liveness
- * marking walks.
- *
- * This was not a problem before because STACK_INVALID is only set by
- * default (where the default reg state has its reg->parent as NULL), or
- * in clean_live_states after REG_LIVE_DONE (at which point
- * mark_reg_read won't walk reg->parent chain), but not randomly during
- * verifier state exploration (like we did above). Hence, for our case
- * parentage chain will still be live (i.e. reg->parent may be
- * non-NULL), while earlier reg->parent was NULL, so we need
- * REG_LIVE_WRITTEN to screen off read marker propagation when it is
- * done later on reads or by mark_dynptr_read as well to unnecessary
- * mark registers in verifier state.
- */
- state->stack[spi].spilled_ptr.live |= REG_LIVE_WRITTEN;
- state->stack[spi - 1].spilled_ptr.live |= REG_LIVE_WRITTEN;
+ bpf_mark_stack_write(env, state->frameno, BIT(spi - 1) | BIT(spi));
}
static int unmark_stack_slots_dynptr(struct bpf_verifier_env *env, struct bpf_reg_state *reg)
@@ -932,9 +913,7 @@ static int destroy_if_dynptr_stack_slot(struct bpf_verifier_env *env,
__mark_reg_not_init(env, &state->stack[spi].spilled_ptr);
__mark_reg_not_init(env, &state->stack[spi - 1].spilled_ptr);
- /* Same reason as unmark_stack_slots_dynptr above */
- state->stack[spi].spilled_ptr.live |= REG_LIVE_WRITTEN;
- state->stack[spi - 1].spilled_ptr.live |= REG_LIVE_WRITTEN;
+ bpf_mark_stack_write(env, state->frameno, BIT(spi - 1) | BIT(spi));
return 0;
}
@@ -1052,7 +1031,6 @@ static int mark_stack_slots_iter(struct bpf_verifier_env *env,
else
st->type |= PTR_UNTRUSTED;
}
- st->live |= REG_LIVE_WRITTEN;
st->ref_obj_id = i == 0 ? id : 0;
st->iter.btf = btf;
st->iter.btf_id = btf_id;
@@ -1062,6 +1040,7 @@ static int mark_stack_slots_iter(struct bpf_verifier_env *env,
for (j = 0; j < BPF_REG_SIZE; j++)
slot->slot_type[j] = STACK_ITER;
+ bpf_mark_stack_write(env, state->frameno, BIT(spi - i));
mark_stack_slot_scratched(env, spi - i);
}
@@ -1087,12 +1066,10 @@ static int unmark_stack_slots_iter(struct bpf_verifier_env *env,
__mark_reg_not_init(env, st);
- /* see unmark_stack_slots_dynptr() for why we need to set REG_LIVE_WRITTEN */
- st->live |= REG_LIVE_WRITTEN;
-
for (j = 0; j < BPF_REG_SIZE; j++)
slot->slot_type[j] = STACK_INVALID;
+ bpf_mark_stack_write(env, state->frameno, BIT(spi - i));
mark_stack_slot_scratched(env, spi - i);
}
@@ -1182,9 +1159,9 @@ static int mark_stack_slot_irq_flag(struct bpf_verifier_env *env,
slot = &state->stack[spi];
st = &slot->spilled_ptr;
+ bpf_mark_stack_write(env, reg->frameno, BIT(spi));
__mark_reg_known_zero(st);
st->type = PTR_TO_STACK; /* we don't have dedicated reg type */
- st->live |= REG_LIVE_WRITTEN;
st->ref_obj_id = id;
st->irq.kfunc_class = kfunc_class;
@@ -1238,8 +1215,7 @@ static int unmark_stack_slot_irq_flag(struct bpf_verifier_env *env, struct bpf_r
__mark_reg_not_init(env, st);
- /* see unmark_stack_slots_dynptr() for why we need to set REG_LIVE_WRITTEN */
- st->live |= REG_LIVE_WRITTEN;
+ bpf_mark_stack_write(env, reg->frameno, BIT(spi));
for (i = 0; i < BPF_REG_SIZE; i++)
slot->slot_type[i] = STACK_INVALID;
@@ -1754,6 +1730,7 @@ static int copy_verifier_state(struct bpf_verifier_state *dst_state,
return err;
dst_state->speculative = src->speculative;
dst_state->in_sleepable = src->in_sleepable;
+ dst_state->cleaned = src->cleaned;
dst_state->curframe = src->curframe;
dst_state->branches = src->branches;
dst_state->parent = src->parent;
@@ -1946,9 +1923,24 @@ static int maybe_exit_scc(struct bpf_verifier_env *env, struct bpf_verifier_stat
return 0;
visit = scc_visit_lookup(env, callchain);
if (!visit) {
- verifier_bug(env, "scc exit: no visit info for call chain %s",
- format_callchain(env, callchain));
- return -EFAULT;
+ /*
+ * If path traversal stops inside an SCC, corresponding bpf_scc_visit
+ * must exist for non-speculative paths. For non-speculative paths
+ * traversal stops when:
+ * a. Verification error is found, maybe_exit_scc() is not called.
+ * b. Top level BPF_EXIT is reached. Top level BPF_EXIT is not a member
+ * of any SCC.
+ * c. A checkpoint is reached and matched. Checkpoints are created by
+ * is_state_visited(), which calls maybe_enter_scc(), which allocates
+ * bpf_scc_visit instances for checkpoints within SCCs.
+ * (c) is the only case that can reach this point.
+ */
+ if (!st->speculative) {
+ verifier_bug(env, "scc exit: no visit info for call chain %s",
+ format_callchain(env, callchain));
+ return -EFAULT;
+ }
+ return 0;
}
if (visit->entry_state != st)
return 0;
@@ -2017,7 +2009,7 @@ static void free_backedges(struct bpf_scc_visit *visit)
for (backedge = visit->backedges; backedge; backedge = next) {
free_verifier_state(&backedge->state, false);
next = backedge->next;
- kvfree(backedge);
+ kfree(backedge);
}
visit->backedges = NULL;
}
@@ -2232,10 +2224,10 @@ static void mark_ptr_not_null_reg(struct bpf_reg_state *reg)
/* transfer reg's id which is unique for every map_lookup_elem
* as UID of the inner map.
*/
- if (btf_record_has_field(map->inner_map_meta->record, BPF_TIMER))
- reg->map_uid = reg->id;
- if (btf_record_has_field(map->inner_map_meta->record, BPF_WORKQUEUE))
+ if (btf_record_has_field(map->inner_map_meta->record,
+ BPF_TIMER | BPF_WORKQUEUE | BPF_TASK_WORK)) {
reg->map_uid = reg->id;
+ }
} else if (map->map_type == BPF_MAP_TYPE_XSKMAP) {
reg->type = PTR_TO_XDP_SOCK;
} else if (map->map_type == BPF_MAP_TYPE_SOCKMAP ||
@@ -2274,7 +2266,8 @@ static bool reg_is_pkt_pointer_any(const struct bpf_reg_state *reg)
static bool reg_is_dynptr_slice_pkt(const struct bpf_reg_state *reg)
{
return base_type(reg->type) == PTR_TO_MEM &&
- (reg->type & DYNPTR_TYPE_SKB || reg->type & DYNPTR_TYPE_XDP);
+ (reg->type &
+ (DYNPTR_TYPE_SKB | DYNPTR_TYPE_XDP | DYNPTR_TYPE_SKB_META));
}
/* Unmodified PTR_TO_PACKET[_META,_END] register from ctx access. */
@@ -2873,8 +2866,6 @@ static void init_reg_state(struct bpf_verifier_env *env,
for (i = 0; i < MAX_BPF_REG; i++) {
mark_reg_not_init(env, regs, i);
- regs[i].live = REG_LIVE_NONE;
- regs[i].parent = NULL;
regs[i].subreg_def = DEF_NOT_SUBREG;
}
@@ -2958,7 +2949,7 @@ static int cmp_subprogs(const void *a, const void *b)
}
/* Find subprogram that contains instruction at 'off' */
-static struct bpf_subprog_info *find_containing_subprog(struct bpf_verifier_env *env, int off)
+struct bpf_subprog_info *bpf_find_containing_subprog(struct bpf_verifier_env *env, int off)
{
struct bpf_subprog_info *vals = env->subprog_info;
int l, r, m;
@@ -2983,7 +2974,7 @@ static int find_subprog(struct bpf_verifier_env *env, int off)
{
struct bpf_subprog_info *p;
- p = find_containing_subprog(env, off);
+ p = bpf_find_containing_subprog(env, off);
if (!p || p->start != off)
return -ENOENT;
return p - env->subprog_info;
@@ -3494,15 +3485,6 @@ static int add_subprog_and_kfunc(struct bpf_verifier_env *env)
return 0;
}
-static int jmp_offset(struct bpf_insn *insn)
-{
- u8 code = insn->code;
-
- if (code == (BPF_JMP32 | BPF_JA))
- return insn->imm;
- return insn->off;
-}
-
static int check_subprogs(struct bpf_verifier_env *env)
{
int i, subprog_start, subprog_end, off, cur_subprog = 0;
@@ -3529,7 +3511,7 @@ static int check_subprogs(struct bpf_verifier_env *env)
goto next;
if (BPF_OP(code) == BPF_EXIT || BPF_OP(code) == BPF_CALL)
goto next;
- off = i + jmp_offset(&insn[i]) + 1;
+ off = i + bpf_jmp_offset(&insn[i]) + 1;
if (off < subprog_start || off >= subprog_end) {
verbose(env, "jump out of range from insn %d to %d\n", i, off);
return -EINVAL;
@@ -3555,69 +3537,15 @@ next:
return 0;
}
-/* Parentage chain of this register (or stack slot) should take care of all
- * issues like callee-saved registers, stack slot allocation time, etc.
- */
-static int mark_reg_read(struct bpf_verifier_env *env,
- const struct bpf_reg_state *state,
- struct bpf_reg_state *parent, u8 flag)
-{
- bool writes = parent == state->parent; /* Observe write marks */
- int cnt = 0;
-
- while (parent) {
- /* if read wasn't screened by an earlier write ... */
- if (writes && state->live & REG_LIVE_WRITTEN)
- break;
- if (verifier_bug_if(parent->live & REG_LIVE_DONE, env,
- "type %s var_off %lld off %d",
- reg_type_str(env, parent->type),
- parent->var_off.value, parent->off))
- return -EFAULT;
- /* The first condition is more likely to be true than the
- * second, checked it first.
- */
- if ((parent->live & REG_LIVE_READ) == flag ||
- parent->live & REG_LIVE_READ64)
- /* The parentage chain never changes and
- * this parent was already marked as LIVE_READ.
- * There is no need to keep walking the chain again and
- * keep re-marking all parents as LIVE_READ.
- * This case happens when the same register is read
- * multiple times without writes into it in-between.
- * Also, if parent has the stronger REG_LIVE_READ64 set,
- * then no need to set the weak REG_LIVE_READ32.
- */
- break;
- /* ... then we depend on parent's value */
- parent->live |= flag;
- /* REG_LIVE_READ64 overrides REG_LIVE_READ32. */
- if (flag == REG_LIVE_READ64)
- parent->live &= ~REG_LIVE_READ32;
- state = parent;
- parent = state->parent;
- writes = true;
- cnt++;
- }
-
- if (env->longest_mark_read_walk < cnt)
- env->longest_mark_read_walk = cnt;
- return 0;
-}
-
static int mark_stack_slot_obj_read(struct bpf_verifier_env *env, struct bpf_reg_state *reg,
int spi, int nr_slots)
{
- struct bpf_func_state *state = func(env, reg);
int err, i;
for (i = 0; i < nr_slots; i++) {
- struct bpf_reg_state *st = &state->stack[spi - i].spilled_ptr;
-
- err = mark_reg_read(env, st, st->parent, REG_LIVE_READ64);
+ err = bpf_mark_stack_read(env, reg->frameno, env->insn_idx, BIT(spi - i));
if (err)
return err;
-
mark_stack_slot_scratched(env, spi - i);
}
return 0;
@@ -3663,7 +3591,7 @@ static int mark_irq_flag_read(struct bpf_verifier_env *env, struct bpf_reg_state
* code only. It returns TRUE if the source or destination register operates
* on 64-bit, otherwise return FALSE.
*/
-static bool is_reg64(struct bpf_verifier_env *env, struct bpf_insn *insn,
+static bool is_reg64(struct bpf_insn *insn,
u32 regno, struct bpf_reg_state *reg, enum reg_arg_type t)
{
u8 code, class, op;
@@ -3774,14 +3702,14 @@ static int insn_def_regno(const struct bpf_insn *insn)
}
/* Return TRUE if INSN has defined any 32-bit value explicitly. */
-static bool insn_has_def32(struct bpf_verifier_env *env, struct bpf_insn *insn)
+static bool insn_has_def32(struct bpf_insn *insn)
{
int dst_reg = insn_def_regno(insn);
if (dst_reg == -1)
return false;
- return !is_reg64(env, insn, dst_reg, NULL, DST_OP);
+ return !is_reg64(insn, dst_reg, NULL, DST_OP);
}
static void mark_insn_zext(struct bpf_verifier_env *env,
@@ -3812,7 +3740,7 @@ static int __check_reg_arg(struct bpf_verifier_env *env, struct bpf_reg_state *r
mark_reg_scratched(env, regno);
reg = &regs[regno];
- rw64 = is_reg64(env, insn, regno, reg, t);
+ rw64 = is_reg64(insn, regno, reg, t);
if (t == SRC_OP) {
/* check whether register used as source operand can be read */
if (reg->type == NOT_INIT) {
@@ -3826,15 +3754,13 @@ static int __check_reg_arg(struct bpf_verifier_env *env, struct bpf_reg_state *r
if (rw64)
mark_insn_zext(env, reg);
- return mark_reg_read(env, reg, reg->parent,
- rw64 ? REG_LIVE_READ64 : REG_LIVE_READ32);
+ return 0;
} else {
/* check whether register used as dest operand can be written to */
if (regno == BPF_REG_FP) {
verbose(env, "frame pointer is read only\n");
return -EACCES;
}
- reg->live |= REG_LIVE_WRITTEN;
reg->subreg_def = rw64 ? DEF_NOT_SUBREG : env->insn_idx + 1;
if (t == DST_OP)
mark_reg_unknown(env, regs, regno);
@@ -4195,7 +4121,7 @@ static void fmt_reg_mask(char *buf, ssize_t buf_sz, u32 reg_mask)
}
}
/* format stack slots bitmask, e.g., "-8,-24,-40" for 0x15 mask */
-static void fmt_stack_mask(char *buf, ssize_t buf_sz, u64 stack_mask)
+void bpf_fmt_stack_mask(char *buf, ssize_t buf_sz, u64 stack_mask)
{
DECLARE_BITMAP(mask, 64);
bool first = true;
@@ -4250,8 +4176,6 @@ static void bt_sync_linked_regs(struct backtrack_state *bt, struct bpf_jmp_histo
}
}
-static bool calls_callback(struct bpf_verifier_env *env, int insn_idx);
-
/* For given verifier state backtrack_insn() is called from the last insn to
* the first insn. Its purpose is to compute a bitmask of registers and
* stack slots that needs precision in the parent verifier state.
@@ -4278,7 +4202,7 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx,
fmt_reg_mask(env->tmp_str_buf, TMP_STR_BUF_LEN, bt_reg_mask(bt));
verbose(env, "mark_precise: frame%d: regs=%s ",
bt->frame, env->tmp_str_buf);
- fmt_stack_mask(env->tmp_str_buf, TMP_STR_BUF_LEN, bt_stack_mask(bt));
+ bpf_fmt_stack_mask(env->tmp_str_buf, TMP_STR_BUF_LEN, bt_stack_mask(bt));
verbose(env, "stack=%s before ", env->tmp_str_buf);
verbose(env, "%d: ", idx);
verbose_insn(env, insn);
@@ -4479,7 +4403,7 @@ static int backtrack_insn(struct bpf_verifier_env *env, int idx, int subseq_idx,
* backtracking, as these registers are set by the function
* invoking callback.
*/
- if (subseq_idx >= 0 && calls_callback(env, subseq_idx))
+ if (subseq_idx >= 0 && bpf_calls_callback(env, subseq_idx))
for (i = BPF_REG_1; i <= BPF_REG_5; i++)
bt_clear_reg(bt, i);
if (bt_reg_mask(bt) & BPF_REGMASK_ARGS) {
@@ -4918,7 +4842,7 @@ static int __mark_chain_precision(struct bpf_verifier_env *env,
bt_frame_reg_mask(bt, fr));
verbose(env, "mark_precise: frame%d: parent state regs=%s ",
fr, env->tmp_str_buf);
- fmt_stack_mask(env->tmp_str_buf, TMP_STR_BUF_LEN,
+ bpf_fmt_stack_mask(env->tmp_str_buf, TMP_STR_BUF_LEN,
bt_frame_stack_mask(bt, fr));
verbose(env, "stack=%s: ", env->tmp_str_buf);
print_verifier_state(env, st, fr, true);
@@ -5041,12 +4965,7 @@ static void assign_scalar_id_before_mov(struct bpf_verifier_env *env,
/* Copy src state preserving dst->parent and dst->live fields */
static void copy_register_state(struct bpf_reg_state *dst, const struct bpf_reg_state *src)
{
- struct bpf_reg_state *parent = dst->parent;
- enum bpf_reg_liveness live = dst->live;
-
*dst = *src;
- dst->parent = parent;
- dst->live = live;
}
static void save_register_state(struct bpf_verifier_env *env,
@@ -5057,8 +4976,6 @@ static void save_register_state(struct bpf_verifier_env *env,
int i;
copy_register_state(&state->stack[spi].spilled_ptr, reg);
- if (size == BPF_REG_SIZE)
- state->stack[spi].spilled_ptr.live |= REG_LIVE_WRITTEN;
for (i = BPF_REG_SIZE; i > BPF_REG_SIZE - size; i--)
state->stack[spi].slot_type[i - 1] = STACK_SPILL;
@@ -5152,6 +5069,18 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
if (err)
return err;
+ if (!(off % BPF_REG_SIZE) && size == BPF_REG_SIZE) {
+ /* only mark the slot as written if all 8 bytes were written
+ * otherwise read propagation may incorrectly stop too soon
+ * when stack slots are partially written.
+ * This heuristic means that read propagation will be
+ * conservative, since it will add reg_live_read marks
+ * to stack slots all the way to first state when programs
+ * writes+reads less than 8 bytes
+ */
+ bpf_mark_stack_write(env, state->frameno, BIT(spi));
+ }
+
check_fastcall_stack_contract(env, state, insn_idx, off);
mark_stack_slot_scratched(env, spi);
if (reg && !(off % BPF_REG_SIZE) && reg->type == SCALAR_VALUE && env->bpf_capable) {
@@ -5195,17 +5124,6 @@ static int check_stack_write_fixed_off(struct bpf_verifier_env *env,
for (i = 0; i < BPF_REG_SIZE; i++)
scrub_spilled_slot(&state->stack[spi].slot_type[i]);
- /* only mark the slot as written if all 8 bytes were written
- * otherwise read propagation may incorrectly stop too soon
- * when stack slots are partially written.
- * This heuristic means that read propagation will be
- * conservative, since it will add reg_live_read marks
- * to stack slots all the way to first state when programs
- * writes+reads less than 8 bytes
- */
- if (size == BPF_REG_SIZE)
- state->stack[spi].spilled_ptr.live |= REG_LIVE_WRITTEN;
-
/* when we zero initialize stack slots mark them as such */
if ((reg && register_is_null(reg)) ||
(!reg && is_bpf_st_mem(insn) && insn->imm == 0)) {
@@ -5398,7 +5316,6 @@ static void mark_reg_stack_read(struct bpf_verifier_env *env,
/* have read misc data from the stack */
mark_reg_unknown(env, state->regs, dst_regno);
}
- state->regs[dst_regno].live |= REG_LIVE_WRITTEN;
}
/* Read the stack at 'off' and put the results into the register indicated by
@@ -5421,12 +5338,16 @@ static int check_stack_read_fixed_off(struct bpf_verifier_env *env,
struct bpf_reg_state *reg;
u8 *stype, type;
int insn_flags = insn_stack_access_flags(reg_state->frameno, spi);
+ int err;
stype = reg_state->stack[spi].slot_type;
reg = &reg_state->stack[spi].spilled_ptr;
mark_stack_slot_scratched(env, spi);
check_fastcall_stack_contract(env, state, env->insn_idx, off);
+ err = bpf_mark_stack_read(env, reg_state->frameno, env->insn_idx, BIT(spi));
+ if (err)
+ return err;
if (is_spilled_reg(&reg_state->stack[spi])) {
u8 spill_size = 1;
@@ -5441,7 +5362,6 @@ static int check_stack_read_fixed_off(struct bpf_verifier_env *env,
return -EACCES;
}
- mark_reg_read(env, reg, reg->parent, REG_LIVE_READ64);
if (dst_regno < 0)
return 0;
@@ -5495,7 +5415,6 @@ static int check_stack_read_fixed_off(struct bpf_verifier_env *env,
insn_flags = 0; /* not restoring original register state */
}
}
- state->regs[dst_regno].live |= REG_LIVE_WRITTEN;
} else if (dst_regno >= 0) {
/* restore register state from stack */
copy_register_state(&state->regs[dst_regno], reg);
@@ -5503,7 +5422,6 @@ static int check_stack_read_fixed_off(struct bpf_verifier_env *env,
* has its liveness marks cleared by is_state_visited()
* which resets stack/reg liveness for state transitions
*/
- state->regs[dst_regno].live |= REG_LIVE_WRITTEN;
} else if (__is_pointer_value(env->allow_ptr_leaks, reg)) {
/* If dst_regno==-1, the caller is asking us whether
* it is acceptable to use this value as a SCALAR_VALUE
@@ -5515,7 +5433,6 @@ static int check_stack_read_fixed_off(struct bpf_verifier_env *env,
off);
return -EACCES;
}
- mark_reg_read(env, reg, reg->parent, REG_LIVE_READ64);
} else {
for (i = 0; i < size; i++) {
type = stype[(slot - i) % BPF_REG_SIZE];
@@ -5529,7 +5446,6 @@ static int check_stack_read_fixed_off(struct bpf_verifier_env *env,
off, i, size);
return -EACCES;
}
- mark_reg_read(env, reg, reg->parent, REG_LIVE_READ64);
if (dst_regno >= 0)
mark_reg_stack_read(env, reg_state, off, off + size, dst_regno);
insn_flags = 0; /* we are not restoring spilled register */
@@ -8157,10 +8073,10 @@ mark:
/* reading any byte out of 8-byte 'spill_slot' will cause
* the whole slot to be marked as 'read'
*/
- mark_reg_read(env, &state->stack[spi].spilled_ptr,
- state->stack[spi].spilled_ptr.parent,
- REG_LIVE_READ64);
- /* We do not set REG_LIVE_WRITTEN for stack slot, as we can not
+ err = bpf_mark_stack_read(env, reg->frameno, env->insn_idx, BIT(spi));
+ if (err)
+ return err;
+ /* We do not call bpf_mark_stack_write(), as we can not
* be sure that whether stack slot is written to or not. Hence,
* we must still conservatively propagate reads upwards even if
* helper may write to the entire memory range.
@@ -8515,34 +8431,62 @@ static int process_spin_lock(struct bpf_verifier_env *env, int regno, int flags)
return 0;
}
-static int process_timer_func(struct bpf_verifier_env *env, int regno,
- struct bpf_call_arg_meta *meta)
+/* Check if @regno is a pointer to a specific field in a map value */
+static int check_map_field_pointer(struct bpf_verifier_env *env, u32 regno,
+ enum btf_field_type field_type)
{
struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
bool is_const = tnum_is_const(reg->var_off);
struct bpf_map *map = reg->map_ptr;
u64 val = reg->var_off.value;
+ const char *struct_name = btf_field_type_name(field_type);
+ int field_off = -1;
if (!is_const) {
verbose(env,
- "R%d doesn't have constant offset. bpf_timer has to be at the constant offset\n",
- regno);
+ "R%d doesn't have constant offset. %s has to be at the constant offset\n",
+ regno, struct_name);
return -EINVAL;
}
if (!map->btf) {
- verbose(env, "map '%s' has to have BTF in order to use bpf_timer\n",
- map->name);
+ verbose(env, "map '%s' has to have BTF in order to use %s\n", map->name,
+ struct_name);
return -EINVAL;
}
- if (!btf_record_has_field(map->record, BPF_TIMER)) {
- verbose(env, "map '%s' has no valid bpf_timer\n", map->name);
+ if (!btf_record_has_field(map->record, field_type)) {
+ verbose(env, "map '%s' has no valid %s\n", map->name, struct_name);
+ return -EINVAL;
+ }
+ switch (field_type) {
+ case BPF_TIMER:
+ field_off = map->record->timer_off;
+ break;
+ case BPF_TASK_WORK:
+ field_off = map->record->task_work_off;
+ break;
+ default:
+ verifier_bug(env, "unsupported BTF field type: %s\n", struct_name);
return -EINVAL;
}
- if (map->record->timer_off != val + reg->off) {
- verbose(env, "off %lld doesn't point to 'struct bpf_timer' that is at %d\n",
- val + reg->off, map->record->timer_off);
+ if (field_off != val + reg->off) {
+ verbose(env, "off %lld doesn't point to 'struct %s' that is at %d\n",
+ val + reg->off, struct_name, field_off);
return -EINVAL;
}
+ return 0;
+}
+
+static int process_timer_func(struct bpf_verifier_env *env, int regno,
+ struct bpf_call_arg_meta *meta)
+{
+ struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
+ struct bpf_map *map = reg->map_ptr;
+ int err;
+
+ err = check_map_field_pointer(env, regno, BPF_TIMER);
+ if (err)
+ return err;
+
if (meta->map_ptr) {
verifier_bug(env, "Two map pointers in a timer helper");
return -EFAULT;
@@ -8573,6 +8517,26 @@ static int process_wq_func(struct bpf_verifier_env *env, int regno,
return 0;
}
+static int process_task_work_func(struct bpf_verifier_env *env, int regno,
+ struct bpf_kfunc_call_arg_meta *meta)
+{
+ struct bpf_reg_state *regs = cur_regs(env), *reg = &regs[regno];
+ struct bpf_map *map = reg->map_ptr;
+ int err;
+
+ err = check_map_field_pointer(env, regno, BPF_TASK_WORK);
+ if (err)
+ return err;
+
+ if (meta->map.ptr) {
+ verifier_bug(env, "Two map pointers in a bpf_task_work helper");
+ return -EFAULT;
+ }
+ meta->map.uid = reg->map_uid;
+ meta->map.ptr = map;
+ return 0;
+}
+
static int process_kptr_func(struct bpf_verifier_env *env, int regno,
struct bpf_call_arg_meta *meta)
{
@@ -10402,6 +10366,8 @@ typedef int (*set_callee_state_fn)(struct bpf_verifier_env *env,
struct bpf_func_state *callee,
int insn_idx);
+static bool is_task_work_add_kfunc(u32 func_id);
+
static int set_callee_state(struct bpf_verifier_env *env,
struct bpf_func_state *caller,
struct bpf_func_state *callee, int insn_idx);
@@ -10620,7 +10586,8 @@ static int push_callback_call(struct bpf_verifier_env *env, struct bpf_insn *ins
env->subprog_info[subprog].is_async_cb = true;
async_cb = push_async_cb(env, env->subprog_info[subprog].start,
insn_idx, subprog,
- is_bpf_wq_set_callback_impl_kfunc(insn->imm));
+ is_bpf_wq_set_callback_impl_kfunc(insn->imm) ||
+ is_task_work_add_kfunc(insn->imm));
if (!async_cb)
return -EFAULT;
callee = async_cb->frame[0];
@@ -10721,6 +10688,8 @@ static int check_func_call(struct bpf_verifier_env *env, struct bpf_insn *insn,
/* and go analyze first insn of the callee */
*insn_idx = env->subprog_info[subprog].start - 1;
+ bpf_reset_live_stack_callchain(env);
+
if (env->log.level & BPF_LOG_LEVEL) {
verbose(env, "caller:\n");
print_verifier_state(env, state, caller->frameno, true);
@@ -10846,7 +10815,7 @@ static int set_timer_callback_state(struct bpf_verifier_env *env,
__mark_reg_not_init(env, &callee->regs[BPF_REG_4]);
__mark_reg_not_init(env, &callee->regs[BPF_REG_5]);
callee->in_async_callback_fn = true;
- callee->callback_ret_range = retval_range(0, 1);
+ callee->callback_ret_range = retval_range(0, 0);
return 0;
}
@@ -10933,6 +10902,36 @@ static int set_rbtree_add_callback_state(struct bpf_verifier_env *env,
return 0;
}
+static int set_task_work_schedule_callback_state(struct bpf_verifier_env *env,
+ struct bpf_func_state *caller,
+ struct bpf_func_state *callee,
+ int insn_idx)
+{
+ struct bpf_map *map_ptr = caller->regs[BPF_REG_3].map_ptr;
+
+ /*
+ * callback_fn(struct bpf_map *map, void *key, void *value);
+ */
+ callee->regs[BPF_REG_1].type = CONST_PTR_TO_MAP;
+ __mark_reg_known_zero(&callee->regs[BPF_REG_1]);
+ callee->regs[BPF_REG_1].map_ptr = map_ptr;
+
+ callee->regs[BPF_REG_2].type = PTR_TO_MAP_KEY;
+ __mark_reg_known_zero(&callee->regs[BPF_REG_2]);
+ callee->regs[BPF_REG_2].map_ptr = map_ptr;
+
+ callee->regs[BPF_REG_3].type = PTR_TO_MAP_VALUE;
+ __mark_reg_known_zero(&callee->regs[BPF_REG_3]);
+ callee->regs[BPF_REG_3].map_ptr = map_ptr;
+
+ /* unused */
+ __mark_reg_not_init(env, &callee->regs[BPF_REG_4]);
+ __mark_reg_not_init(env, &callee->regs[BPF_REG_5]);
+ callee->in_async_callback_fn = true;
+ callee->callback_ret_range = retval_range(S32_MIN, S32_MAX);
+ return 0;
+}
+
static bool is_rbtree_lock_required_kfunc(u32 btf_id);
/* Are we currently verifying the callback for a rbtree helper that must
@@ -10996,8 +10995,7 @@ static int prepare_func_exit(struct bpf_verifier_env *env, int *insn_idx)
}
/* we are going to rely on register's precise value */
- err = mark_reg_read(env, r0, r0->parent, REG_LIVE_READ64);
- err = err ?: mark_chain_precision(env, BPF_REG_0);
+ err = mark_chain_precision(env, BPF_REG_0);
if (err)
return err;
@@ -11007,7 +11005,7 @@ static int prepare_func_exit(struct bpf_verifier_env *env, int *insn_idx)
"At callback return", "R0");
return -EINVAL;
}
- if (!calls_callback(env, callee->callsite)) {
+ if (!bpf_calls_callback(env, callee->callsite)) {
verifier_bug(env, "in callback at %d, callsite %d !calls_callback",
*insn_idx, callee->callsite);
return -EFAULT;
@@ -11645,7 +11643,8 @@ static int check_helper_call(struct bpf_verifier_env *env, struct bpf_insn *insn
if (dynptr_type == BPF_DYNPTR_TYPE_INVALID)
return -EFAULT;
- if (dynptr_type == BPF_DYNPTR_TYPE_SKB)
+ if (dynptr_type == BPF_DYNPTR_TYPE_SKB ||
+ dynptr_type == BPF_DYNPTR_TYPE_SKB_META)
/* this will trigger clear_all_pkt_pointers(), which will
* invalidate all dynptr slices associated with the skb
*/
@@ -11900,17 +11899,11 @@ static void __mark_btf_func_reg_size(struct bpf_verifier_env *env, struct bpf_re
if (regno == BPF_REG_0) {
/* Function return value */
- reg->live |= REG_LIVE_WRITTEN;
reg->subreg_def = reg_size == sizeof(u64) ?
DEF_NOT_SUBREG : env->insn_idx + 1;
- } else {
+ } else if (reg_size == sizeof(u64)) {
/* Function argument */
- if (reg_size == sizeof(u64)) {
- mark_insn_zext(env, reg);
- mark_reg_read(env, reg, reg->parent, REG_LIVE_READ64);
- } else {
- mark_reg_read(env, reg, reg->parent, REG_LIVE_READ32);
- }
+ mark_insn_zext(env, reg);
}
}
@@ -12063,6 +12056,7 @@ enum {
KF_ARG_RB_NODE_ID,
KF_ARG_WORKQUEUE_ID,
KF_ARG_RES_SPIN_LOCK_ID,
+ KF_ARG_TASK_WORK_ID,
};
BTF_ID_LIST(kf_arg_btf_ids)
@@ -12073,6 +12067,7 @@ BTF_ID(struct, bpf_rb_root)
BTF_ID(struct, bpf_rb_node)
BTF_ID(struct, bpf_wq)
BTF_ID(struct, bpf_res_spin_lock)
+BTF_ID(struct, bpf_task_work)
static bool __is_kfunc_ptr_arg_type(const struct btf *btf,
const struct btf_param *arg, int type)
@@ -12121,6 +12116,11 @@ static bool is_kfunc_arg_wq(const struct btf *btf, const struct btf_param *arg)
return __is_kfunc_ptr_arg_type(btf, arg, KF_ARG_WORKQUEUE_ID);
}
+static bool is_kfunc_arg_task_work(const struct btf *btf, const struct btf_param *arg)
+{
+ return __is_kfunc_ptr_arg_type(btf, arg, KF_ARG_TASK_WORK_ID);
+}
+
static bool is_kfunc_arg_res_spin_lock(const struct btf *btf, const struct btf_param *arg)
{
return __is_kfunc_ptr_arg_type(btf, arg, KF_ARG_RES_SPIN_LOCK_ID);
@@ -12208,6 +12208,7 @@ enum kfunc_ptr_arg_type {
KF_ARG_PTR_TO_WORKQUEUE,
KF_ARG_PTR_TO_IRQ_FLAG,
KF_ARG_PTR_TO_RES_SPIN_LOCK,
+ KF_ARG_PTR_TO_TASK_WORK,
};
enum special_kfunc_type {
@@ -12232,6 +12233,8 @@ enum special_kfunc_type {
KF_bpf_rbtree_right,
KF_bpf_dynptr_from_skb,
KF_bpf_dynptr_from_xdp,
+ KF_bpf_dynptr_from_skb_meta,
+ KF_bpf_xdp_pull_data,
KF_bpf_dynptr_slice,
KF_bpf_dynptr_slice_rdwr,
KF_bpf_dynptr_clone,
@@ -12256,6 +12259,8 @@ enum special_kfunc_type {
KF_bpf_res_spin_lock_irqsave,
KF_bpf_res_spin_unlock_irqrestore,
KF___bpf_trap,
+ KF_bpf_task_work_schedule_signal,
+ KF_bpf_task_work_schedule_resume,
};
BTF_ID_LIST(special_kfunc_list)
@@ -12281,9 +12286,13 @@ BTF_ID(func, bpf_rbtree_right)
#ifdef CONFIG_NET
BTF_ID(func, bpf_dynptr_from_skb)
BTF_ID(func, bpf_dynptr_from_xdp)
+BTF_ID(func, bpf_dynptr_from_skb_meta)
+BTF_ID(func, bpf_xdp_pull_data)
#else
BTF_ID_UNUSED
BTF_ID_UNUSED
+BTF_ID_UNUSED
+BTF_ID_UNUSED
#endif
BTF_ID(func, bpf_dynptr_slice)
BTF_ID(func, bpf_dynptr_slice_rdwr)
@@ -12322,6 +12331,14 @@ BTF_ID(func, bpf_res_spin_unlock)
BTF_ID(func, bpf_res_spin_lock_irqsave)
BTF_ID(func, bpf_res_spin_unlock_irqrestore)
BTF_ID(func, __bpf_trap)
+BTF_ID(func, bpf_task_work_schedule_signal)
+BTF_ID(func, bpf_task_work_schedule_resume)
+
+static bool is_task_work_add_kfunc(u32 func_id)
+{
+ return func_id == special_kfunc_list[KF_bpf_task_work_schedule_signal] ||
+ func_id == special_kfunc_list[KF_bpf_task_work_schedule_resume];
+}
static bool is_kfunc_ret_null(struct bpf_kfunc_call_arg_meta *meta)
{
@@ -12353,6 +12370,11 @@ static bool is_kfunc_bpf_preempt_enable(struct bpf_kfunc_call_arg_meta *meta)
return meta->func_id == special_kfunc_list[KF_bpf_preempt_enable];
}
+static bool is_kfunc_pkt_changing(struct bpf_kfunc_call_arg_meta *meta)
+{
+ return meta-&