Merge tag 'locking-urgent-2023-11-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

torvalds · torvalds · commit 1d0dbc3d16e8 · 2023-11-26T08:30:11.000-08:00
Pull locking fix from Ingo Molnar:
 "Fix lockdep block chain corruption resulting in KASAN warnings"

* tag 'locking-urgent-2023-11-26' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  lockdep: Fix block chain corruption
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
@@ -3497,7 +3497,8 @@ static int alloc_chain_hlocks(int req)
 		size = chain_block_size(curr);
 		if (likely(size >= req)) {
 			del_chain_block(0, size, chain_block_next(curr));
-			add_chain_block(curr + req, size - req);
+			if (size > req)
+				add_chain_block(curr + req, size - req);
 			return curr;
 		}
 	}

Original file line number	Diff line number	Diff line change
`@@ -3497,7 +3497,8 @@ static int alloc_chain_hlocks(int req)`
`3497`	`3497`	`size = chain_block_size(curr);`
`3498`	`3498`	`if (likely(size >= req)) {`
`3499`	`3499`	`del_chain_block(0, size, chain_block_next(curr));`
`3500`		`- add_chain_block(curr + req, size - req);`
	`3500`	`+ if (size > req)`
	`3501`	`+ add_chain_block(curr + req, size - req);`
`3501`	`3502`	`return curr;`
`3502`	`3503`	`}`
`3503`	`3504`	`}`