Merge tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Pull bpf fixes from Daniel Borkmann:

 - Fix an out-of-bounds read in bpf_link_show_fdinfo for BPF sockmap
   link file descriptors (Hou Tao)

 - Fix BPF arm64 JIT's address emission with tag-based KASAN enabled
   reserving not enough size (Peter Collingbourne)

 - Fix BPF verifier do_misc_fixups patching for inlining of the
   bpf_get_branch_snapshot BPF helper (Andrii Nakryiko)

 - Fix a BPF verifier bug and reject BPF program write attempts into
   read-only marked BPF maps (Daniel Borkmann)

 - Fix perf_event_detach_bpf_prog error handling by removing an invalid
   check which would skip BPF program release (Jiri Olsa)

 - Fix memory leak when parsing mount options for the BPF filesystem
   (Hou Tao)

* tag 'bpf-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf: Check validity of link->type in bpf_link_show_fdinfo()
  bpf: Add the missing BPF_LINK_TYPE invocation for sockmap
  bpf: fix do_misc_fixups() for bpf_get_branch_snapshot()
  bpf,perf: Fix perf_event_detach_bpf_prog error handling
  selftests/bpf: Add test for passing in uninit mtu_len
  selftests/bpf: Add test for writes to .rodata
  bpf: Remove MEM_UNINIT from skb/xdp MTU helpers
  bpf: Fix overloading of MEM_UNINIT's meaning
  bpf: Add MEM_WRITE attribute
  bpf: Preserve param->string when parsing mount options
  bpf, arm64: Fix address emission with tag-based KASAN enabled

4 files changed, 70 insertions, 1 deletions

diff --git a/tools/include/uapi/linux/bpf.h b/tools/include/uapi/linux/bpf.h
index e8241b320c6d..4a939c90dc2e 100644
--- a/tools/include/uapi/linux/bpf.h
+++ b/tools/include/uapi/linux/bpf.h
@@ -1121,6 +1121,9 @@ enum bpf_attach_type {
 
 #define MAX_BPF_ATTACH_TYPE __MAX_BPF_ATTACH_TYPE
 
+/* Add BPF_LINK_TYPE(type, name) in bpf_types.h to keep bpf_link_type_strs[]
+ * in sync with the definitions below.
+ */
 enum bpf_link_type {
 	BPF_LINK_TYPE_UNSPEC = 0,
 	BPF_LINK_TYPE_RAW_TRACEPOINT = 1,
diff --git a/tools/testing/selftests/bpf/prog_tests/verifier.c b/tools/testing/selftests/bpf/prog_tests/verifier.c
index 5356f26bbb3f..75f7a2ce334b 100644
--- a/tools/testing/selftests/bpf/prog_tests/verifier.c
+++ b/tools/testing/selftests/bpf/prog_tests/verifier.c
@@ -54,6 +54,7 @@
 #include "verifier_masking.skel.h"
 #include "verifier_meta_access.skel.h"
 #include "verifier_movsx.skel.h"
+#include "verifier_mtu.skel.h"
 #include "verifier_netfilter_ctx.skel.h"
 #include "verifier_netfilter_retcode.skel.h"
 #include "verifier_bpf_fastcall.skel.h"
@@ -223,6 +224,24 @@ void test_verifier_xdp_direct_packet_access(void) { RUN(verifier_xdp_direct_pack
 void test_verifier_bits_iter(void) { RUN(verifier_bits_iter); }
 void test_verifier_lsm(void)                  { RUN(verifier_lsm); }
 
+void test_verifier_mtu(void)
+{
+	__u64 caps = 0;
+	int ret;
+
+	/* In case CAP_BPF and CAP_PERFMON is not set */
+	ret = cap_enable_effective(1ULL << CAP_BPF | 1ULL << CAP_NET_ADMIN, &caps);
+	if (!ASSERT_OK(ret, "set_cap_bpf_cap_net_admin"))
+		return;
+	ret = cap_disable_effective(1ULL << CAP_SYS_ADMIN | 1ULL << CAP_PERFMON, NULL);
+	if (!ASSERT_OK(ret, "disable_cap_sys_admin"))
+		goto restore_cap;
+	RUN(verifier_mtu);
+restore_cap:
+	if (caps)
+		cap_enable_effective(caps, NULL);
+}
+
 static int init_test_val_map(struct bpf_object *obj, char *map_name)
 {
 	struct test_val value = {
diff --git a/tools/testing/selftests/bpf/progs/verifier_const.c b/tools/testing/selftests/bpf/progs/verifier_const.c
index 2e533d7eec2f..e118dbb768bf 100644
--- a/tools/testing/selftests/bpf/progs/verifier_const.c
+++ b/tools/testing/selftests/bpf/progs/verifier_const.c
@@ -1,8 +1,9 @@
 // SPDX-License-Identifier: GPL-2.0
 /* Copyright (c) 2024 Isovalent */
 
-#include <linux/bpf.h>
+#include "vmlinux.h"
 #include <bpf/bpf_helpers.h>
+#include <bpf/bpf_tracing.h>
 #include "bpf_misc.h"
 
 const volatile long foo = 42;
@@ -66,4 +67,32 @@ int tcx6(struct __sk_buff *skb)
 	return TCX_PASS;
 }
 
+static inline void write_fixed(volatile void *p, __u32 val)
+{
+	*(volatile __u32 *)p = val;
+}
+
+static inline void write_dyn(void *p, void *val, int len)
+{
+	bpf_copy_from_user(p, len, val);
+}
+
+SEC("tc/ingress")
+__description("rodata/mark: write with unknown reg rejected")
+__failure __msg("write into map forbidden")
+int tcx7(struct __sk_buff *skb)
+{
+	write_fixed((void *)&foo, skb->mark);
+	return TCX_PASS;
+}
+
+SEC("lsm.s/bprm_committed_creds")
+__description("rodata/mark: write with unknown reg rejected")
+__failure __msg("write into map forbidden")
+int BPF_PROG(bprm, struct linux_binprm *bprm)
+{
+	write_dyn((void *)&foo, &bart, bpf_get_prandom_u32() & 3);
+	return 0;
+}
+
 char LICENSE[] SEC("license") = "GPL";
diff --git a/tools/testing/selftests/bpf/progs/verifier_mtu.c b/tools/testing/selftests/bpf/progs/verifier_mtu.c
new file mode 100644
index 000000000000..70c7600a26a0
--- /dev/null
+++ b/tools/testing/selftests/bpf/progs/verifier_mtu.c
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#include "vmlinux.h"
+#include <bpf/bpf_helpers.h>
+#include "bpf_misc.h"
+
+SEC("tc/ingress")
+__description("uninit/mtu: write rejected")
+__failure __msg("invalid indirect read from stack")
+int tc_uninit_mtu(struct __sk_buff *ctx)
+{
+	__u32 mtu;
+
+	bpf_check_mtu(ctx, 0, &mtu, 0, 0);
+	return TCX_PASS;
+}
+
+char LICENSE[] SEC("license") = "GPL";