bpf: mark a NULL kfunc argument precisegrafted

check_kfunc_arg() allows bpf_register_is_null() for nullable arguments
w/o marking the underlying scalar register precise. Hence a checkpoint
created on such a path would prune against arbitrary scalar value.

Fixes: 3bda08b63670 ("bpf: Allow NULL buffers in bpf_dynptr_slice(_rw)")
Signed-off-by: Eduard Zingerman <eddyz87@gmail.com>
Link: https://lore.kernel.org/r/20260904-register-is-null-precise-fixes-v1-5-0f5a360ff15d@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

1 files changed, 43 insertions, 0 deletions

diff --git a/Documentation/admin-guide/device-mapper/index.rst b/Documentation/admin-guide/device-mapper/index.rst
new file mode 100644
index 000000000..73c1f2002
--- /dev/null
+++ b/Documentation/admin-guide/device-mapper/index.rst
@@ -0,0 +1,43 @@
+=============
+Device Mapper
+=============
+
+.. toctree::
+    :maxdepth: 1
+
+    cache-policies
+    cache
+    delay
+    dm-clone
+    dm-crypt
+    dm-dust
+    dm-ebs
+    dm-flakey
+    dm-ima
+    dm-init
+    dm-inlinecrypt
+    dm-integrity
+    dm-io
+    dm-log
+    dm-pcache
+    dm-queue-length
+    dm-raid
+    dm-service-time
+    dm-uevent
+    dm-zoned
+    era
+    kcopyd
+    linear
+    log-writes
+    persistent-data
+    snapshot
+    statistics
+    striped
+    switch
+    thin-provisioning
+    unstriped
+    vdo-design
+    vdo
+    verity
+    writecache
+    zero