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 1B9BE2FAE for ; Mon, 14 Nov 2022 18:30:06 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 5FF7DC433D6; Mon, 14 Nov 2022 18:30:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1668450606; bh=KjLeGyUJTbZpSiKhaAFgRkOpgkH4ndx+JjCuYdxHGcY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bY29PN+CyQgg6/VdgLjSq/jugOiRFtHQw+Xxc1h2PxY+BLAsSfEJ7e2CBv4KzGmfy 9/aoiEiu5ZSpriSJuR0gSVUmS+zYRvGafuYYtqMPEQDS2NhqQ1kwYdncApO+p92FTX stqy0WYhQYHGIR+bGkXrE3FUPMGugEp+sWfx013Sj93aJjNN7z2YCazcoSLdPWMwYs QdyULgUxl+x46SDTihwnGa4I8eGqJGE7esekjFcM5kv73P444WCvBH9nP8vA/qDCO7 rNn+jHctDyZHC5FSnsfooLElEb7u553FDcpbSBpBYlKV87QumPpjh6nmUZjpp5/d6T jXDfBuLGLo+CQ== From: SeongJae Park To: SeongJae Park , Andrew Morton Cc: damon@lists.linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: [PATCH mm-unstable 2/2] mm/damon/sysfs-schemes: skip schemes regions clearing if the scheme directory has removed Date: Mon, 14 Nov 2022 18:29:54 +0000 Message-Id: <20221114182954.4745-3-sj@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20221114182954.4745-1-sj@kernel.org> References: <20221114182954.4745-1-sj@kernel.org> Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit A DAMON sysfs interface user can start DAMON with a scheme, remove the sysfs directory for the scheme, and then ask clearing of the scheme's tried regions. Because the schemes tried regions clearing logic doesn't aware of the situation, it results in an invalid memory access. Fix the bug by checking if the scheme sysfs directory exists. Fixes: bb9641eb3a3e ("mm/damon/sysfs-schemes: implement DAMOS-tried regions clear command") # mm-unstable Signed-off-by: SeongJae Park --- mm/damon/sysfs-schemes.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/mm/damon/sysfs-schemes.c b/mm/damon/sysfs-schemes.c index 4df3c99983e8..e6baf55d617d 100644 --- a/mm/damon/sysfs-schemes.c +++ b/mm/damon/sysfs-schemes.c @@ -1260,6 +1260,10 @@ int damon_sysfs_schemes_clear_regions( damon_for_each_scheme(scheme, ctx) { struct damon_sysfs_scheme *sysfs_scheme; + /* user could removed the scheme sysfs dir */ + if (schemes_idx >= sysfs_schemes->nr) + break; + sysfs_scheme = sysfs_schemes->schemes_arr[schemes_idx++]; damon_sysfs_scheme_regions_rm_dirs( sysfs_scheme->tried_regions); -- 2.25.1