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 A057C1DFFB; Fri, 29 May 2026 00:12:22 +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=1780013543; cv=none; b=Z2y4AyqTWt7UtgNAo+smzI5UffQNtP2izq35ed+mGpSy1JoC/9o29MDUika6YVggxQm20D37YFWASxYes8OgbzCxsx5a6YhCWDO4f/RE0jaRh04kbKxpEwzIUkPleW3tBQnCXL9Jkmoi4zgJoxUur56u/nmXl+5H/MYZu8RAk6c= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780013543; c=relaxed/simple; bh=ms73O5CGb5I26p6B8UM9XQQuu7rKG89arC7xlwXKkk0=; h=Date:To:From:Subject:Message-Id; b=KmZuVaOrqdJBpPGGOQczQTy1mR3QtftNZv73ym3dQFLxdudqzhxgWkT/DtC6HP1NtjhpC3Dy9gtxy19lAD3LnoeEC3Mz7/bVWkUAjCBrrRxh1Uv8BOd9fF7jsXNInvNuJTILUWe3J2DIqQZLju/aNs/M/tRkt56uCmpznjqvnb8= 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=oyerUa6Z; 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="oyerUa6Z" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 362D11F000E9; Fri, 29 May 2026 00:12:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1780013542; bh=DjcRoblmu8Rixu/kzN6ldqxcxN9vAxh23jP0z+URLUo=; h=Date:To:From:Subject; b=oyerUa6ZWjAPHh5esDiQY0PsMDrxKbdYWjNIOwyIbansr6ESc3Fa9r5ZKQVOZ+/QV q4nIgCgQlFTzWBYJrJJtGVbbTJ2xgjOD6wZ/+VC0sVYcXvxc7YCpyaotL01eX5VUDc 5VXxwbug2OuexcEaajNHnNE2/hs27pASFr3VBmPo= Date: Thu, 28 May 2026 17:12:21 -0700 To: mm-commits@vger.kernel.org,stable@vger.kernel.org,sj@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-damon-reclaim-handle-ctx-allocation-failure.patch added to mm-hotfixes-unstable branch Message-Id: <20260529001222.362D11F000E9@smtp.kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/damon/reclaim: handle ctx allocation failure has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-damon-reclaim-handle-ctx-allocation-failure.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-damon-reclaim-handle-ctx-allocation-failure.patch This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm 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: SeongJae Park Subject: mm/damon/reclaim: handle ctx allocation failure Date: Thu, 28 May 2026 17:01:02 -0700 Patch series "mm/damon/{reclaim,lru_sort}: handle ctx allocation failures". DAMON_RECLAIM and DAMON_LRU_SORT could dereference NULL pointers if their damon_ctx object allocations fail. The bugs are expected to happen infrequently because the allocations are arguably too small to fail on common setups. But theoretically they are possible and the consequences are bad. Fix those. The issues were discovered [1] by Sashiko. This patch (of 2): DAMON_RECLAIM allocates the damon_ctx object for its kdamond in its init function. damon_reclaim_enabled_store() wrongly assumes the allocation will always succeed once tried. If the damon_ctx allocation was failed, therefore, code execution reaches to damon_commit_ctx() while 'ctx' is NULL. As a result, it dereferences the NULL 'ctx' pointer. Avoid the NULL dereference by returning -ENOMEM if 'ctx' is NULL. Link: https://lore.kernel.org/20260529000104.7006-2-sj@kernel.org Link: https://lore.kernel.org/20260419014800.877-1-sj@kernel.org [1] Fixes: 3f7a914ab9a5 ("mm/damon/reclaim: use damon_initialized()") Signed-off-by: SeongJae Park Cc: # 6.18.x Signed-off-by: Andrew Morton --- mm/damon/reclaim.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/mm/damon/reclaim.c~mm-damon-reclaim-handle-ctx-allocation-failure +++ a/mm/damon/reclaim.c @@ -339,6 +339,10 @@ static int damon_reclaim_enabled_store(c if (!damon_initialized()) return 0; + /* damon_modules_new_paddr_ctx_target() in the init function failed. */ + if (!ctx) + return -ENOMEM; + return damon_reclaim_turn(enabled); } _ Patches currently in -mm which might be from sj@kernel.org are mm-damon-ops-common-call-folio_test_lru-after-folio_get.patch mm-damon-reclaim-handle-ctx-allocation-failure.patch mm-damonn-lru_sort-handle-ctx-allocation-failure.patch mm-damon-core-make-charge_addr_from-aware-of-end-address-exclusivity.patch mm-damon-core-handle-min_region_sz-remaining-quota-as-empty.patch mm-damon-core-merge-regions-after-applying-damos-schemes.patch mm-damon-core-introduce-failed-region-quota-charge-ratio.patch mm-damon-sysfs-schemes-implement-fail_charge_numdenom-files.patch docs-mm-damon-design-document-fail_charge_numdenom.patch docs-admin-guide-mm-damon-usage-document-fail_charge_numdenom-files.patch docs-abi-damon-document-fail_charge_numdenom.patch mm-damon-tests-core-kunit-test-fail_charge_numdenom-committing.patch selftests-damon-_damon_sysfs-support-failed-region-quota-charge-ratio.patch selftests-damon-drgn_dump_damon_status-support-failed-region-quota-charge-ratio.patch selftests-damon-sysfspy-test-failed-region-quota-charge-ratio.patch docs-mm-damon-maintainer-profile-add-ai-review-usage-guideline.patch mm-damon-core-introduce-damon_ctx-paused.patch mm-damon-sysfs-add-pause-file-under-context-dir.patch docs-mm-damon-design-update-for-context-pause-resume-feature.patch docs-admin-guide-mm-damon-usage-update-for-pause-file.patch docs-abi-damon-update-for-pause-sysfs-file.patch mm-damon-tests-core-kunit-test-pause-commitment.patch selftests-damon-_damon_sysfs-support-pause-file-staging.patch selftests-damon-drgn_dump_damon_status-dump-pause.patch selftests-damon-sysfspy-check-pause-on-assert_ctx_committed.patch selftests-damon-sysfspy-pause-damon-before-dumping-status.patch mm-damon-introduce-damon_set_region_system_rams_default.patch mm-damon-reclaim-cover-all-system-rams.patch mm-damon-lru_sort-cover-all-system-rams.patch mm-damon-core-remove-damon_set_region_biggest_system_ram_default.patch mm-damon-stat-use-damon_set_region_system_rams_default.patch docs-admin-guide-mm-damon-reclaim-update-for-entire-memory-monitoring.patch docs-admin-guide-mm-damon-lru_sort-update-for-entire-memory-monitoring.patch docs-admin-guide-mm-damon-usage-mark-scheme-filters-sysfs-dir-as-deprecated.patch docs-abi-damon-mark-schemes-s-filters-deprecated.patch mm-damon-reclaim-add-autotune_monitoring_intervals-parameter.patch docs-admin-guide-mm-damon-reclaim-update-for-autotune_monitoring_intervals.patch mm-damon-stat-add-a-parameter-for-reading-kdamond-pid.patch docs-admin-guide-mm-damon-stat-document-kdamond_pid-parameter.patch mm-damon-core-introduce-struct-damon_probe.patch mm-damon-core-embed-damon_probe-objects-in-damon_ctx.patch mm-damon-core-introduce-damon_filter.patch mm-damon-core-commit-probes.patch mm-damon-core-introduce-damon_region-probe_hits.patch mm-damon-core-introduce-damon_ops-apply_probes.patch mm-damon-core-do-data-attributes-monitoring.patch mm-damon-paddr-support-data-attributes-monitoring.patch mm-damon-sysfs-implement-probes-dir.patch mm-damon-sysfs-implement-probe-dir.patch mm-damon-sysfs-implement-filters-directory.patch mm-damon-sysfs-implement-filter-dir.patch mm-damon-sysfs-implement-filter-dir-files.patch mm-damon-sysfs-setup-probes-on-damon-core-api-parameters.patch mm-damon-sysfs-schemes-implement-tried_regions-r-probes.patch mm-damon-sysfs-schemes-implement-probe-dir.patch mm-damon-sysfs-schemes-implement-probe-hits-file.patch mm-damon-trace-probe_hits.patch selftests-damon-sysfssh-test-probes-dir.patch docs-mm-damon-design-document-data-attributes-monitoring.patch docs-admin-guide-mm-damon-usage-document-data-attributes-monitoring.patch mm-damon-core-introduce-damon_filter_type_memcg.patch mm-damon-paddr-support-damon_filter_type_memcg.patch mm-damon-sysfs-add-filters-f-path-file.patch mm-damon-sysfs-schemes-move-memcg_path_to_id-to-sysfs-common.patch mm-damon-sysfs-setup-damon_filter-memcg_id-from-path.patch docs-mm-damon-design-update-for-memcg-damon-filter.patch docs-admin-guide-mm-damon-usage-update-for-memcg-damon-filter.patch mm-damon-core-safely-handle-no-region-case-in-damon_set_regions.patch mm-damon-core-do-not-use-region-out-of-a-loop-in-damon_set_regions.patch samples-damon-mtier-replace-damon_add_region-with-damon_set_regions.patch mm-damon-tests-vaddr-kunit-replace-damon_add_region-with-damon_set_regions.patch mm-damon-core-hide-damon_add_region.patch mm-damon-core-hide-damon_insert_region.patch mm-damon-core-hide-damon_destroy_region.patch mm-damon-core-add-kdamond_call-debug_sanity-check.patch mm-damon-core-remove-damon_verify_nr_regions.patch mm-damon-tests-core-kunit-add-damon_set_regions-test-cases.patch selftests-damon-sysfspy-stop-kdamonds-before-failing.patch selftests-damon-sysfssh-test-monitoring-intervals-goal-dir.patch selftests-damon-sysfssh-test-addr_unit-file-existence.patch selftests-damon-sysfssh-test-pause-file-existence.patch mm-damon-core-trace-esz-at-first-setup.patch