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 168B3418359 for ; Thu, 3 Sep 2026 20:44:59 +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=1788468308; cv=none; b=CyvKXFoD74qV3SVX2nuRkT6vRFrYIfRL+CUaZLhCfIfzUqa39F7X3VAGT6rIJ/ST3ulxcwgWJs4t+i3ATIXwL0aQCP4PgIXYxkEyKhh1EuGV/cNS9VkepwA1qm1rmisPQ+SphpCwEqP+h4T7lvb+y9vQhfSZjgsTh4kZVZzV39Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788468308; c=relaxed/simple; bh=LWvbc9G1X3FOZUEiDw0BThl0UZ3XhEVsSH7qfI8MA2Y=; h=Date:To:From:Subject:Message-Id; b=fMCKlUy1OM5VYOlaX+3ukjnXiY45GyUrbQGUDmzZRVT8BWQORa7FjkNFrxghKNwp73kNxl5rkikxPBLH3r9Hqi/oCSFGzgdrRIGwkciVzzHkXUxxINb8kJB3PkVDn2vac4GTBH+5a8d9DsXOJnjhC/G/G8QaQC+1dEVz2h7IIEc= 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=TkrdK2FS; 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="TkrdK2FS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 56C061F000E9; Thu, 3 Sep 2026 20:44:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1788468295; bh=VEABHH8CiiZzWj4NM8h/1QSMxVUUcBbU6Enn4Cn5hhE=; h=Date:To:From:Subject; b=TkrdK2FS5BDLSuOj8IoTAC9Q3Efi7Bf+Dg2StxnhsKLiMrdYcyWbeA0fVGSi/JPHB s1RMVK2gIjNLmsxexcdCeLwKV9yi2kyUfL1+xoqs90mTI9o5WkYWK7HrITKPgpuBBW A7jkmlwL0/9bmBc28u2zTgE9tMzzmVWtBkUUC/R8= Date: Thu, 03 Sep 2026 13:44:54 -0700 To: mm-commits@vger.kernel.org,sj@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-damon-core-handle-null-ctx-parameter-in-damon_call.patch added to mm-new branch Message-Id: <20260903204455.56C061F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/damon/core: handle NULL ctx parameter in damon_call() has been added to the -mm mm-new branch. Its filename is mm-damon-core-handle-null-ctx-parameter-in-damon_call.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-damon-core-handle-null-ctx-parameter-in-damon_call.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: SJ Park Subject: mm/damon/core: handle NULL ctx parameter in damon_call() Date: Wed, 2 Sep 2026 18:03:30 -0700 Patch series "mm/damon: allow NULL or unstarted damon_ctx parameter for damon_call()". Callers of damon_call() should validate the damon_ctx object parameter. If it is NULL or never damon_start()-ed object, damon_call() could dereference the NULL pointer or indefinitely hang. Ensuring all callers doing the validation correctly has turned out to be difficult. Handle the corner cases inside the core layer and remove callers' validations. Patches 1 and 2 respectively allow passing NULL and not yet damon_start()-ed ctx parameter to damon_call(). Patches 3 and 4 remove the callers side validations in DMON_RECLAIM and DASMON_LRU_SORT, respectively. This patch (of 4): When NULL damon_ctx pointer parameter is passed, damon_call() could do NULL dereference. The caller is responsible to avoid that. It is easy to forget, and there are many damon_call() callers. Meanwhile, damon_call() is never meant to be performance critical. It uses mutex and completion. Add the NULL pointer check inside damon_call() so that callers can pass the parameter without NULL checks. Link: https://lore.kernel.org/20260903010334.93622-1-sj@kernel.org Link: https://lore.kernel.org/20260903010334.93622-2-sj@kernel.org Signed-off-by: SJ Park Signed-off-by: Andrew Morton --- mm/damon/core.c | 2 ++ 1 file changed, 2 insertions(+) --- a/mm/damon/core.c~mm-damon-core-handle-null-ctx-parameter-in-damon_call +++ a/mm/damon/core.c @@ -2216,6 +2216,8 @@ int damon_kdamond_pid(struct damon_ctx * */ int damon_call(struct damon_ctx *ctx, struct damon_call_control *control) { + if (!ctx) + return -EINVAL; if (!control->repeat) init_completion(&control->completion); control->canceled = false; _ Patches currently in -mm which might be from sj@kernel.org are mm-damon-core-skip-applying-scheme-if-region-split-for-quota-fails.patch mm-damon-paddr-respect-folio-end-for-damos_stat.patch mm-damon-paddr-respect-folio-end-for-damos-actions-except-stat.patch mm-damon-vaddr-respect-folio-end-for-damos_stat.patch mm-damon-vaddr-respect-folio-end-for-damos_migrate_hotcold.patch mm-damon-core-handle-extreme-memory-state-in-damon_get_node_mem_bp.patch mm-damon-core-handle-extreme-memory-state-in-get_node_memcg_used_bp.patch mm-damon-core-handle-extreme-memory-state-in-get_in_active_mem_bp.patch mm-damon-core-introduce-damon_filter_type_pgidle_unset.patch mm-damon-paddr-support-pgidle_unset-probe-filter-type.patch mm-damon-sysfs-support-pgidle_unset-probe-filter-type.patch docs-mm-damon-design-document-pgidle_unset-probe-filter-type.patch mm-damon-core-introduce-damon_prep-struct.patch mm-damon-core-commit-preps.patch mm-damon-core-introduce-damon_operations-prep_probes.patch mm-damon-paddr-support-damon_prep.patch mm-damon-sysfs-implement-preps-directory.patch mm-damon-sysfs-implement-preps-nr_preps-file.patch mm-damon-sysfs-create-directories-for-nr_preps-writes.patch mm-damon-sysfs-implement-prep_action-file.patch mm-damon-sysfs-pass-preps-to-damon-core.patch selftests-damon-sysfssh-test-probe-prep-sysfs-files.patch docs-mm-damon-design-document-probe-preps.patch docs-admin-guide-mm-damon-usage-document-probe-preps-sysfs-files.patch docs-abi-damon-document-probe-prep-sysfs-files.patch mm-damon-tests-core-kunit-test-committing-psi-goal-to-psi-goal.patch mm-damon-core-handle-uninitialized-damos_quota_goal-last_psi_total.patch mm-damon-core-copy-nid-for-eligible_mem_bp-damos-quota-goal-commit.patch mm-damon-sysfs-set-next-refresh-jiffies-per-sysfs-context.patch mm-damon-tests-core-kunit-test-damon_commit_filter.patch mm-damon-tests-core-kunit-add-damon_commit_probes-test.patch selftests-damon-_damon_sysfs-implement-damonprobes.patch selftests-damon-drgn_dump_damon_status-dump-probes.patch selftests-damon-sysfspy-extend-commit-assertion-function-for-probes.patch selftests-damon-sysfspy-test-damon-probes.patch mm-damon-core-use-damon_nr_samples_per_aggr-for-max-merge-threshold.patch mm-damon-core-remove-debug-messages.patch mm-damon-core-remove-debug-messages-fix.patch mm-damon-vaddr-remove-a-debug-message.patch mm-damon-core-validate-number-of-probes-in-valid_probe_params.patch mm-damon-sysfs-remove-probes-number-validation.patch mm-damon-tests-core-kunit-extend-set_regions-test-for-error-case.patch mm-damon-tests-core-kunit-test-=0-size-damon_set_regions-inputs.patch mm-damon-tests-core-kunit-test-overlapping-ranges-for-set_regions.patch mm-damon-tests-core-kunit-test-damon_nr_samples_per_aggr.patch selftests-damon-sysfssh-test-hugepage_mem_bp-quota-goal.patch docs-mm-damon-maintainer-profile-update-ai-review-for-sashiko-replies.patch docs-abi-damon-recommend-subsystem-doc-instead-of-admin-guide.patch mm-damon-core-error-damos_commit_quota_goal-for-zero-target_value.patch revert-mm-damon-lru_sort-error-out-for-10000-active_mem_bp.patch revert-samples-damon-mtier-error-out-for-zero-quota-goal-target-values.patch mm-damon-core-handle-null-ctx-parameter-in-damon_call.patch mm-damon-core-set-ctx-call_controls_obsolete-in-damon_new_ctx.patch mm-damon-reclaim-remove-unnecessary-damon_call-param-validation.patch mm-damon-lru_sort-remove-unnecessary-damon_call-param-validation.patch