Merge branch 'stricter register ID checking in regsafe()'

Eduard Zingerman says:

====================

This patch-set consists of a series of bug fixes for register ID
tracking in verifier.c:states_equal()/regsafe() functions:
 - for registers of type PTR_TO_MAP_{KEY,VALUE}, PTR_TO_PACKET[_META]
   the regsafe() should call check_ids() even if registers are
   byte-to-byte equal;
 - states_equal() must maintain idmap that covers all function frames
   in the state because functions like mark_ptr_or_null_regs() operate
   on all registers in the state;
 - regsafe() must compare spin lock ids for PTR_TO_MAP_VALUE registers.

The last point covers issue reported by Kumar Kartikeya Dwivedi in [1],
I borrowed the test commit from there.
Note, that there is also an issue with register id tracking for
scalars described here [2], it would be addressed separately.

[1] https://lore.kernel.org/bpf/20221111202719.982118-1-memxor@gmail.com/
[2] https://lore.kernel.org/bpf/20221128163442.280187-2-eddyz87@gmail.com/

Eduard Zingerman (6):
  bpf: regsafe() must not skip check_ids()
  selftests/bpf: test cases for regsafe() bug skipping check_id()
  bpf: states_equal() must build idmap for all function frames
  selftests/bpf: verify states_equal() maintains idmap across all frames
  bpf: use check_ids() for active_lock comparison
  selftests/bpf: test case for relaxed prunning of active_lock.id
====================

Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 2 insertions, 2 deletions

diff --git a/include/linux/bpf_verifier.h b/include/linux/bpf_verifier.h
index df0cb825e0e3..53d175cbaa02 100644
--- a/include/linux/bpf_verifier.h
+++ b/include/linux/bpf_verifier.h
@@ -273,9 +273,9 @@ struct bpf_id_pair {
 	u32 cur;
 };
 
-/* Maximum number of register states that can exist at once */
-#define BPF_ID_MAP_SIZE (MAX_BPF_REG + MAX_BPF_STACK / BPF_REG_SIZE)
 #define MAX_CALL_FRAMES 8
+/* Maximum number of register states that can exist at once */
+#define BPF_ID_MAP_SIZE ((MAX_BPF_REG + MAX_BPF_STACK / BPF_REG_SIZE) * MAX_CALL_FRAMES)
 struct bpf_verifier_state {
 	/* call stack tracking */
 	struct bpf_func_state *frame[MAX_CALL_FRAMES];