From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 446D220DD51 for ; Sun, 5 Jul 2026 02:11:44 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783217505; cv=none; b=cWuf3rYuVicKk16SycY8Hr7BWHhFKtlzVFLV1+lo3o5I12LhVIKnwufmOiIc4SbCYyM0SiP3y3xaxgmGQvWUQdw1Zgeta78h3JOGtS4yooezx4roAGWX5CbFW+2ADXHFLoO+dkoAJaPqlIyJexp/+afzCxSJ1uhZ9dIHNE0YSeI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783217505; c=relaxed/simple; bh=cQWrC3T+lQ/g3YKFhzgNqaqOPnX4TJbKFfZpRhAL7Yg=; h=Date:To:From:Subject:Message-Id; b=DhxiBHGI/YVwgGo3zqzfEfzKslcUCv7qUXkbtL0QuSJmZ6orXa+R6wFUHGNiQ2hMwzLnXp1OGFPTNAGG+fq+Q4slmk3nd9jj9osczRWW/ha7zhxQAdHcWO4R41e3pvvrt9+NvKvU72RMP10f80ZLeyXmiiICNEWp3CfnnZVyz6M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=FFT7xoqI; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="FFT7xoqI" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1861D1F000E9; Sun, 5 Jul 2026 02:11:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1783217504; bh=JbEWqylWemFjeFErwjpyVu5f5Yelk9FdbjDHUV1/PhI=; h=Date:To:From:Subject; b=FFT7xoqIJEGiNuSUPTQDXJ+fArnzp/qq0POu7OV92RE6eJuXeL3Ja7HL0unGTU+z6 C9REA1FYdPFHx7Ih1PPfx/TJBZY3S+Pq25/b/e33bskbMUF5OeIJq8Sjzpm92L91Eb r2ofuOA+9rhcPs/SADetI4w83UzsBvKOfO6uX4mo= Date: Sat, 04 Jul 2026 19:11:43 -0700 To: mm-commits@vger.kernel.org,kent.overstreet@linux.dev,catalin.marinas@arm.com,bigeasy@linutronix.de,arnd@arndb.de,leitao@debian.org,akpm@linux-foundation.org From: Andrew Morton Subject: + radix-tree-fix-kmemleak-false-positives-on-tree-head-reassignment.patch added to mm-new branch Message-Id: <20260705021144.1861D1F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: radix-tree: fix kmemleak false positives on tree head reassignment has been added to the -mm mm-new branch. Its filename is radix-tree-fix-kmemleak-false-positives-on-tree-head-reassignment.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/radix-tree-fix-kmemleak-false-positives-on-tree-head-reassignment.patch This patch will later appear in the mm-new branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Note, mm-new is a provisional staging ground for work-in-progress patches, and acceptance into mm-new is a notification for others take notice and to finish up reviews. Please do not hesitate to respond to review feedback and post updated versions to replace or incrementally fixup patches in mm-new. The mm-new branch of mm.git is not included in linux-next If a few days of testing in mm-new is successful, the patch will me moved into mm.git's mm-unstable branch, which is included in linux-next Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Breno Leitao Subject: radix-tree: fix kmemleak false positives on tree head reassignment Date: Fri, 03 Jul 2026 08:22:03 -0700 Kmemleak periodically reports transient false positives for radix tree nodes allocated through the IDR, for example: unreferenced object 0xffff0004d6ac4200 (size 576): comm "tcpeventd", pid 6412 backtrace (crc 335d668a): kmem_cache_alloc_noprof radix_tree_node_alloc radix_tree_extend idr_get_free idr_alloc_cyclic map_create __sys_bpf radix_tree_extend() (grow) and radix_tree_shrink() (shrink) repoint root->xa_head to a new node. If a kmemleak scan has already walked past root->xa_head, the new head is not reachable from any scanned pointer until the following scan, so kmemleak reports it as leaked even though it is live. This is the same race fixed for the XArray API in commit a1a029bcea59 ("XArray: fix kmemleak false positive in xas_shrink()"). The IDR uses the radix tree API directly and hits it on both the grow and the shrink path, so mark the new head as a transient leak in both. Add a matching kmemleak_transient_leak() stub to the radix tree test harness so the userspace lib/radix-tree.c build keeps building. Link: https://lore.kernel.org/20260703-radix-tree-v2-1-38bb6efb5f6e@debian.org Signed-off-by: Breno Leitao Cc: Arnd Bergmann Cc: Catalin Marinas Cc: Kent Overstreet Cc: Sebastian Andrzej Siewior Signed-off-by: Andrew Morton --- lib/radix-tree.c | 7 ++++++- tools/testing/shared/linux/kmemleak.h | 1 + 2 files changed, 7 insertions(+), 1 deletion(-) --- a/lib/radix-tree.c~radix-tree-fix-kmemleak-false-positives-on-tree-head-reassignment +++ a/lib/radix-tree.c @@ -455,6 +455,8 @@ static int radix_tree_extend(struct radi node->slots[0] = (void __rcu *)entry; entry = node_to_entry(node); rcu_assign_pointer(root->xa_head, entry); + /* new head may be missed by an in-progress kmemleak scan */ + kmemleak_transient_leak(node); shift += RADIX_TREE_MAP_SHIFT; } while (shift <= maxshift); out: @@ -495,8 +497,11 @@ static inline bool radix_tree_shrink(str if (!node->shift && is_idr(root)) break; - if (radix_tree_is_internal_node(child)) + if (radix_tree_is_internal_node(child)) { entry_to_node(child)->parent = NULL; + /* new head may be missed by an in-progress kmemleak scan */ + kmemleak_transient_leak(entry_to_node(child)); + } /* * We don't need rcu_assign_pointer(), since we are simply --- a/tools/testing/shared/linux/kmemleak.h~radix-tree-fix-kmemleak-false-positives-on-tree-head-reassignment +++ a/tools/testing/shared/linux/kmemleak.h @@ -1 +1,2 @@ static inline void kmemleak_update_trace(const void *ptr) { } +static inline void kmemleak_transient_leak(const void *ptr) { } _ Patches currently in -mm which might be from leitao@debian.org are mm-kmemleak-fix-checksum-computation-for-per-cpu-objects.patch mm-kmemleak-avoid-soft-lockup-when-scanning-task-stacks.patch mm-kmemleak-stop-the-task-stack-scan-early-when-interrupted.patch mm-kmemleak-stop-the-per-cpu-and-struct-page-scans-early-too.patch mm-memory-failure-drop-dead-error_states-entry-for-reserved-pages.patch mm-memory-failure-surface-unhandlable-kernel-pages-as-enotrecoverable.patch mm-memory-failure-report-mf_msg_kernel-for-unrecoverable-kernel-pages.patch mm-memory-failure-add-panic-option-for-unrecoverable-pages.patch documentation-document-panic_on_unrecoverable_memory_failure-sysctl.patch selftests-mm-add-hwpoison-panic-destructive-test.patch mm-kmemleak-skip-the-remaining-scan-phases-when-interrupted.patch radix-tree-fix-kmemleak-false-positives-on-tree-head-reassignment.patch