From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 B20761A9F8C for ; Fri, 8 May 2026 19:10:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778267454; cv=none; b=Y8E14Accm22tHhX3YVS9Dc2e1QqtE4Yijr2dwPRLhngkWgBTWHlCKE/iu/+uu95n0ysi4DTJ4QlQ+FS70wETVvu70PGuf5JYwSCmwn52bCAu7tx0ElrubnUlSVsDa2xUMbrSkxgN2Pccl0rbJEFXPbBaz5MNAbqJMhG4SkkxEDI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1778267454; c=relaxed/simple; bh=IxFWhosczW10OUNTEtwlxmZ+VftMaDSQNbEARzKVXbU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Du0N8zEf+9yod0ZumWKEEm8bfjYDBKOocyg7fGgyMLJeAFOrl4S5Kpt0sv/jMO0EOemHNs0IE/0wUCGskeVU9hOQGVwCIqA2YrJiQvtkEpFKO2LDLF84ncjpl7Zfo3kKHf9coX3KFsJcNm5zdOVOzJpejVxubnTHcG0qjQeyimg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GgMI8J9r; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="GgMI8J9r" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9D97BC2BCC7; Fri, 8 May 2026 19:10:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1778267454; bh=IxFWhosczW10OUNTEtwlxmZ+VftMaDSQNbEARzKVXbU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GgMI8J9r0Q3mcH94SzHJrLlJ04iKib1/bWe3D4uSZBfMlaIOpUaMvssEYpEx8t2XE p/F7tZT0iTcE5C7xAraLbPezYQClhxYUgeKT9Vdf6syOqPaeOpHllgQQ6LHFctdcZz EjRrO1LXniBaFIpM52+s6gIwSfPOfFyCoe8Z1W7fVuotItXvbxYoicHiqQznhpC7Dk yetTdiC63/4vFD0UwMr0jhkg9V7c3B99eoZ1ZbIjJiluYCkQ73sLlTdG2MDrDnaFnT 8YOWAEd1+t1UwMg9a459nJopW57s2N5ZhOGmlv3HzUdZB59F8U63SnmaI1D7o0hF0P tOYLWDvW/g/4w== From: Sasha Levin To: stable@vger.kernel.org Cc: "Uladzislau Rezki (Sony)" , Baoquan He , chenyichong , Andrew Morton , Sasha Levin Subject: [PATCH 6.12.y] mm/vmalloc: take vmap_purge_lock in shrinker Date: Fri, 8 May 2026 15:10:50 -0400 Message-ID: <20260508191051.1831166-1-sashal@kernel.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <2026050349-operation-curled-2359@gregkh> References: <2026050349-operation-curled-2359@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: "Uladzislau Rezki (Sony)" [ Upstream commit ec05f51f1e65bce95528543eb73fda56fd201d94 ] decay_va_pool_node() can be invoked concurrently from two paths: __purge_vmap_area_lazy() when pools are being purged, and the shrinker via vmap_node_shrink_scan(). However, decay_va_pool_node() is not safe to run concurrently, and the shrinker path currently lacks serialization, leading to races and possible leaks. Protect decay_va_pool_node() by taking vmap_purge_lock in the shrinker path to ensure serialization with purge users. Link: https://lore.kernel.org/20260413192646.14683-1-urezki@gmail.com Fixes: 7679ba6b36db ("mm: vmalloc: add a shrinker to drain vmap pools") Signed-off-by: Uladzislau Rezki (Sony) Reviewed-by: Baoquan He Cc: chenyichong Cc: Signed-off-by: Andrew Morton [ kept index-based loop instead of for_each_vmap_node() helper ] Signed-off-by: Sasha Levin --- mm/vmalloc.c | 1 + 1 file changed, 1 insertion(+) diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 1d2262fb54185..d4a42980b4d02 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -5204,6 +5204,7 @@ vmap_node_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) { int i; + guard(mutex)(&vmap_purge_lock); for (i = 0; i < nr_vmap_nodes; i++) decay_va_pool_node(&vmap_nodes[i], true); -- 2.53.0