From mboxrd@z Thu Jan 1 00:00:00 1970 From: Waiman Long Subject: [PATCH v4 1/2] bdi, blk-cgroup: Fix potential UAF of blkcg Date: Wed, 14 Dec 2022 22:31:31 -0500 Message-ID: <20221215033132.230023-2-longman@redhat.com> References: <20221215033132.230023-1-longman@redhat.com> Mime-Version: 1.0 Content-Transfer-Encoding: base64 Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1671075113; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=JQg3oq06Uw+1wG32ld/l34XBIlmOl7KcZS/r8y8eH90=; b=BNOOOfQqNCwnIVq5uI1Gv6r+0NBA2km1aEquWDKmN4DNp7r+/v11I1OPj3bGw6cdDIQEpU 1TOr/FBSkY210y0yAYAfKtD9T9M8YrAaZcti41LBW9f7Z3YgU9izwICJ/C602IYdW44erP SBAdBBFAT/9pC3hP+W6Oj3Snax2UcRc= In-Reply-To: <20221215033132.230023-1-longman-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> List-ID: Content-Type: text/plain; charset="macroman" To: Jens Axboe , Tejun Heo , Josef Bacik , Zefan Li , Johannes Weiner , Andrew Morton Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, =?UTF-8?q?Michal=20Koutn=C3=BD?= , "Dennis Zhou (Facebook)" , Waiman Long , Yi Zhang Q29tbWl0IDU5YjU3NzE3ZmZmOCAoImJsa2NnOiBkZWxheSBibGtnIGRlc3RydWN0aW9uIHVudGls IGFmdGVyCndyaXRlYmFjayBoYXMgZmluaXNoZWQiKSBkZWxheWVkIGNhbGwgdG8gYmxrY2dfZGVz dHJveV9ibGtncygpIHRvCmNnd2JfcmVsZWFzZV93b3JrZm4oKS4gSG93ZXZlciwgaXQgaXMgZG9u ZSBhZnRlciBhIGNzc19wdXQoKSBvZiBibGtjZwp3aGljaCBtYXkgYmUgdGhlIGZpbmFsIHB1dCB0 aGF0IGNhdXNlcyB0aGUgYmxrY2cgdG8gYmUgZnJlZWQgYXMgUkNVCnJlYWQgbG9jayBpc24ndCBo ZWxkLgoKQW5vdGhlciBwbGFjZSB3aGVyZSBibGtjZ19kZXN0cm95X2Jsa2dzKCkgY2FuIGJlIGNh bGxlZCBpbmRpcmVjdGx5IHZpYQpibGtjZ191bnBpbl9vbmxpbmUoKSBpcyBmcm9tIHRoZSBvZmZs aW5lX2NzcygpIGZ1bmN0aW9uIGNhbGxlZCBmcm9tCmNzc19raWxsZWRfd29ya19mbigpLiBPdmVy IHRoZXJlLCB0aGUgcG90ZW50aWFsbHkgZmluYWwgY3NzX3B1dCgpIGNhbGwKaXMgaXNzdWVkIGFm dGVyIG9mZmxpbmVfY3NzKCkuCgpCeSBhZGRpbmcgYSBjc3NfdHJ5Z2V0KCkgaW50byBibGtjZ19k ZXN0cm95X2Jsa2dzKCkgYW5kIHdhcm5pbmcgaXRzCmZhaWx1cmUsIHRoZSBmb2xsb3dpbmcgc3Rh Y2sgdHJhY2Ugd2FzIHByb2R1Y2VkIGluIGEgdGVzdCBzeXN0ZW0gb24KYm9vdHVwLgoKWyAgIDM0 LjI1NDI0MF0gUklQOiAwMDEwOmJsa2NnX2Rlc3Ryb3lfYmxrZ3MrMHgxNmEvMHgxYTAKICAgICAg OgpbICAgMzQuMzM5OTQzXSBDYWxsIFRyYWNlOgpbICAgMzQuMzQ0NTEwXSAgYmxrY2dfdW5waW5f b25saW5lKzB4MzgvMHg2MApbICAgMzQuMzQ4NTIzXSAgY2d3Yl9yZWxlYXNlX3dvcmtmbisweDZh LzB4MjAwClsgICAzNC4zNTI3MDhdICBwcm9jZXNzX29uZV93b3JrKzB4MWU1LzB4M2IwClsgICAz NC4zNjA3NThdICB3b3JrZXJfdGhyZWFkKzB4NTAvMHgzYTAKWyAgIDM0LjM2ODQ0N10gIGt0aHJl YWQrMHhkOS8weDEwMApbICAgMzQuMzc2Mzg2XSAgcmV0X2Zyb21fZm9yaysweDIyLzB4MzAKClRo aXMgY29uZmlybXMgdGhhdCBhIHBvdGVudGlhbCBVQUYgc2l0dWF0aW9uIGNhbiByZWFsbHkgaGFw cGVuIGluCmNnd2JfcmVsZWFzZV93b3JrZm4oKS4KCkZpeCB0aGF0IGJ5IGRlbGF5aW5nIHRoZSBj c3NfcHV0KCkgdW50aWwgYWZ0ZXIgdGhlIGJsa2NnX3VucGluX29ubGluZSgpCmNhbGwuIEFsc28g dXNlIHBlcmNwdV9yZWZfaXNfemVybygpIGluIGJsa2NnX2Rlc3Ryb3lfYmxrZ3MoKSBhbmQgaXNz dWUKYSB3YXJuaW5nIGlmIHJlZmVyZW5jZSBjb3VudCBpcyB6ZXJvLgoKVGhlIHJlcHJvZHVjaW5n IHN5c3RlbSBjYW4gbm8gbG9uZ2VyIHByb2R1Y2UgYSB3YXJuaW5nIHdpdGggdGhpcyBwYXRjaC4K QWxsIHRoZSBydW5uYWJsZSBibG9jay8wKiB0ZXN0cyBpbmNsdWRpbmcgYmxvY2svMDI3IHdlcmUg cnVuIHN1Y2Nlc3NmdWxseQp3aXRob3V0IGZhaWx1cmUuCgpGaXhlczogNTliNTc3MTdmZmY4ICgi YmxrY2c6IGRlbGF5IGJsa2cgZGVzdHJ1Y3Rpb24gdW50aWwgYWZ0ZXIgd3JpdGViYWNrIGhhcyBm aW5pc2hlZCIpClN1Z2dlc3RlZC1ieTogTWljaGFsIEtvdXRuw70gPG1rb3V0bnktSUJpOVJHL2I2 N2tAcHVibGljLmdtYW5lLm9yZz4KUmVwb3J0ZWQtYnk6IFlpIFpoYW5nIDx5aS56aGFuZy1IK3dY YUh4ZjdhTFFUMGRaUitBbGZBQHB1YmxpYy5nbWFuZS5vcmc+ClNpZ25lZC1vZmYtYnk6IFdhaW1h biBMb25nIDxsb25nbWFuLUgrd1hhSHhmN2FMUVQwZFpSK0FsZkFAcHVibGljLmdtYW5lLm9yZz4K QWNrZWQtYnk6ICBUZWp1biBIZW8gPHRqLURnRWpUK0FpMnlnZG5tK3lST2ZFMEFAcHVibGljLmdt YW5lLm9yZz4KLS0tCiBibG9jay9ibGstY2dyb3VwLmMgfCA3ICsrKysrKysKIG1tL2JhY2tpbmct ZGV2LmMgICB8IDggKysrKysrLS0KIDIgZmlsZXMgY2hhbmdlZCwgMTMgaW5zZXJ0aW9ucygrKSwg MiBkZWxldGlvbnMoLSkKCmRpZmYgLS1naXQgYS9ibG9jay9ibGstY2dyb3VwLmMgYi9ibG9jay9i bGstY2dyb3VwLmMKaW5kZXggMWJiOTM5ZDNiNzkzLi5jYTI4MzA2YWExYjEgMTAwNjQ0Ci0tLSBh L2Jsb2NrL2Jsay1jZ3JvdXAuYworKysgYi9ibG9jay9ibGstY2dyb3VwLmMKQEAgLTEwODQsNiAr MTA4NCwxMyBAQCBzdHJ1Y3QgbGlzdF9oZWFkICpibGtjZ19nZXRfY2d3Yl9saXN0KHN0cnVjdCBj Z3JvdXBfc3Vic3lzX3N0YXRlICpjc3MpCiAgKi8KIHN0YXRpYyB2b2lkIGJsa2NnX2Rlc3Ryb3lf YmxrZ3Moc3RydWN0IGJsa2NnICpibGtjZykKIHsKKwkvKgorCSAqIGJsa2NnX2Rlc3Ryb3lfYmxr Z3MoKSBzaG91bGRuJ3QgYmUgY2FsbGVkIHdpdGggYWxsIHRoZSBibGtjZworCSAqIHJlZmVyZW5j ZXMgZ29uZS4KKwkgKi8KKwlpZiAoV0FSTl9PTl9PTkNFKHBlcmNwdV9yZWZfaXNfemVybygmYmxr Y2ctPmNzcy5yZWZjbnQpKSkKKwkJcmV0dXJuOworCiAJbWlnaHRfc2xlZXAoKTsKIAogCXNwaW5f bG9ja19pcnEoJmJsa2NnLT5sb2NrKTsKZGlmZiAtLWdpdCBhL21tL2JhY2tpbmctZGV2LmMgYi9t bS9iYWNraW5nLWRldi5jCmluZGV4IGMzMDQxOWE1ZTExOS4uMzZmNzViMDcyMzI1IDEwMDY0NAot LS0gYS9tbS9iYWNraW5nLWRldi5jCisrKyBiL21tL2JhY2tpbmctZGV2LmMKQEAgLTM5MCwxMSAr MzkwLDE1IEBAIHN0YXRpYyB2b2lkIGNnd2JfcmVsZWFzZV93b3JrZm4oc3RydWN0IHdvcmtfc3Ry dWN0ICp3b3JrKQogCXdiX3NodXRkb3duKHdiKTsKIAogCWNzc19wdXQod2ItPm1lbWNnX2Nzcyk7 Ci0JY3NzX3B1dCh3Yi0+YmxrY2dfY3NzKTsKIAltdXRleF91bmxvY2soJndiLT5iZGktPmNnd2Jf cmVsZWFzZV9tdXRleCk7CiAKLQkvKiB0cmlnZ2VycyBibGtnIGRlc3RydWN0aW9uIGlmIG5vIG9u bGluZSB1c2VycyBsZWZ0ICovCisJLyoKKwkgKiBUcmlnZ2VycyBibGtnIGRlc3RydWN0aW9uIGlm IG5vIG9ubGluZSB1c2VycyBsZWZ0CisJICogVGhlIGZpbmFsIGJsa2NnIGNzc19wdXQoKSBoYXMg dG8gYmUgZG9uZSBhZnRlciBibGtjZ191bnBpbl9vbmxpbmUoKQorCSAqIHRvIGF2b2lkIHVzZS1h ZnRlci1mcmVlLgorCSAqLwogCWJsa2NnX3VucGluX29ubGluZSh3Yi0+YmxrY2dfY3NzKTsKKwlj c3NfcHV0KHdiLT5ibGtjZ19jc3MpOwogCiAJZnByb3BfbG9jYWxfZGVzdHJveV9wZXJjcHUoJndi LT5tZW1jZ19jb21wbGV0aW9ucyk7CiAKLS0gCjIuMzEuMQoK