Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions).
As found with Coccinelle[1], add __counted_by for struct afs_permits. [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci Cc: David Howells <dhowe...@redhat.com> Cc: Marc Dionne <marc.dio...@auristor.com> Cc: linux-...@lists.infradead.org Signed-off-by: Kees Cook <keesc...@chromium.org> --- fs/afs/internal.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/afs/internal.h b/fs/afs/internal.h index 07433a5349ca..469a717467a4 100644 --- a/fs/afs/internal.h +++ b/fs/afs/internal.h @@ -705,7 +705,7 @@ struct afs_permits { refcount_t usage; unsigned short nr_permits; /* Number of records */ bool invalidated; /* Invalidated due to key change */ - struct afs_permit permits[]; /* List of permits sorted by key pointer */ + struct afs_permit permits[] __counted_by(nr_permits); /* List of permits sorted by key pointer */ }; /* -- 2.34.1
