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 AA1AE38398F; Sat, 12 Sep 2026 18:19:07 +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=1789237148; cv=none; b=dCDyDeEg6lLwuKRV4duQDKJ++LNTfvAoRomAgY1S2S28BK5N1LBozr+HIJ7N+xQJwz4S0oRRRQW+ttEHcaztZOjre7Si8a71oQKUuATSiQbn8g38aoATyjUKOz513Q9kYLbG60xJfvKOrFPfZPxsZ6fGMSYrX0Kfd9dQQ0ru8eY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789237148; c=relaxed/simple; bh=Y9pWfQOH1mB4P2FAkNT6tvSzsVPrhzFi4K+mQoWpl6o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=IYyRROvkDLCEbnjvfZABVSqjEPxow8Su/oNTsVDI6qIjhOz8O9+qu7BofJu9cwP71LENCkVv8PCBrMYJ78FQky6k7oEV39nvLpH3s/u/3foWTZrxWl5pVsGYGKEuUj2A1GNH2qRR3rSxAfx21YscMWW1SM/3jYMuJ7xRbr/Yd5c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=e8RhhTZ1; 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="e8RhhTZ1" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4B5D91F000FF; Sat, 12 Sep 2026 18:19:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789237147; bh=qtNjrHvoxGb9heBd70BDfQ0uFWuhHJw/c0b4dbGhKYA=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=e8RhhTZ1FG+vri4hc72FLO7dIrChD/KABPQ23hpyaAijISEEmIpgV5p/wukkxMYJ6 oCdw+LeoVIRbp0gcWNQZZ0FCN6snfeX6T0DHqCQ/VQTJTHW1DMT7q7vRB4gAJB4fob rWAfBBgOWWgKu5r/j9Ou6ayWWPRMS16/nPASZ9GM= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Junzhe Yu , Mikulas Patocka Subject: [PATCH 5.15 199/935] dm-stats: fix a crash if allocation of per-cpu data fails Date: Sat, 12 Sep 2026 08:53:49 +0200 Message-ID: <20260912065531.379732209@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260912065526.833703348@linuxfoundation.org> References: <20260912065526.833703348@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 5.15-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);