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 D3113356744; Sat, 12 Sep 2026 15:41:41 +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=1789227702; cv=none; b=bbcYpP1WjWfhciGP9v239101YTsf2/SsrMMXjddjVVS+/JAWtuYryvixMeTo5/mYPXNJt8g49KGVUxkllpIdz8p24D25+8VLkZW11TqK+IblRlrK8p1PdHXQbnhCQKwZKrnEH835/q8VL/83TJVc/Y9pfXAjQXQNeUAohQVGhhs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789227702; c=relaxed/simple; bh=TAM6og897sDD8cTPqC4/KWWJUGwQmleIR1HDEn/Rc4Q=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Lc/dR66xjYIydcGdDF84na3rOVHCymowoT6byelpcUayY6Z+dhGmjXXqrNlG6xiOIeSi8FUAchg1m0QM83Fs46L7zP8tz2BEaKnXDl/7e16MoXkvR0Y/BruZOTsVZT2R/SMIqfUFn/etrkKK1BbjnaSuoU/eI3BxK++NIOf8SUM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=EOkdVTA3; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="EOkdVTA3" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 424B01F000FF; Sat, 12 Sep 2026 15:41:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789227701; bh=yvYLcU8uaYc6MQ7GTSJg0YZka+qPIhCrMihNk2JL2XE=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=EOkdVTA3tpdS9xzf044ga8RQ8ror56qyVzZgVzxbYzj9MOmoBYytTbez/mY9woQW3 JyWUH9tMIFzQzYGj2R1izLp2vHEUf0wxCqu3Z8iV2nrZQlQxcTq7TYCZiSRRRO39ml lOcffQQ7BgLK+ay4q+XXU7P6kzj9ebyF5WXavp4k= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Junzhe Yu , Mikulas Patocka Subject: [PATCH 6.1 0233/1191] dm-stats: fix a crash if allocation of per-cpu data fails Date: Sat, 12 Sep 2026 08:49:21 +0200 Message-ID: <20260912065553.444338212@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065548.086904252@linuxfoundation.org> References: <20260912065548.086904252@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.1-stable review patch. If anyone has any objections, please let me know. ------------------ From: Mikulas Patocka commit cc87e26d9cce22061dc21e51e11afef29dbbc36a upstream. If "dm_kvzalloc(percpu_alloc_size, cpu_to_node(cpu))" fails, the code jumps to the "out" label and calls dm_stat_free. dm_stat_free does "for_each_possible_cpu(cpu) { dm_kvfree(s->stat_percpu[cpu][0].histogram, s->histogram_alloc_size);", which crashes with NULL pointer dereference if s->stat_percpu[cpu] is NULL. This commit fixes the bug by testing s->stat_percpu[cpu] for NULL before using it. Reported-by: Junzhe Yu Signed-off-by: Mikulas Patocka Fixes: fd2ed4d25270 ("dm: add statistics support") Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-stats.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/md/dm-stats.c +++ b/drivers/md/dm-stats.c @@ -175,8 +175,10 @@ static void dm_stat_free(struct rcu_head kfree(s->program_id); kfree(s->aux_data); for_each_possible_cpu(cpu) { - dm_kvfree(s->stat_percpu[cpu][0].histogram, s->histogram_alloc_size); - dm_kvfree(s->stat_percpu[cpu], s->percpu_alloc_size); + if (s->stat_percpu[cpu]) { + dm_kvfree(s->stat_percpu[cpu][0].histogram, s->histogram_alloc_size); + dm_kvfree(s->stat_percpu[cpu], s->percpu_alloc_size); + } } dm_kvfree(s->stat_shared[0].tmp.histogram, s->histogram_alloc_size); dm_kvfree(s, s->shared_alloc_size);