From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 22373CCA492 for ; Wed, 8 Jun 2022 00:38:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235361AbiFHAim (ORCPT ); Tue, 7 Jun 2022 20:38:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:50650 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1385401AbiFGWVg (ORCPT ); Tue, 7 Jun 2022 18:21:36 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F2855267168; Tue, 7 Jun 2022 12:21:26 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 797DD609FA; Tue, 7 Jun 2022 19:21:26 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7FF1AC385A5; Tue, 7 Jun 2022 19:21:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1654629685; bh=9DMQ6JgSqIf8HKJKCjCTfDvP43n2npVk0dYewib4UoM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tghiLop6c8U2C0wkH/ba4INnI0cvi2WKOz4lCgArqKqjaQpTjpoSjzaqHOnXnlivM 65aTXDfCBaf93iz1439BrPyjsOSODoFZG3FNb3v68u48fBKe84ByjjWSua/Mqv21/b yM0Lrr6C4SgGzex0nycd+RyNcxGDtP9eeVFOLyCM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Andreas Gruenbacher , Alexander Aring , David Teigland Subject: [PATCH 5.18 763/879] dlm: fix plock invalid read Date: Tue, 7 Jun 2022 19:04:41 +0200 Message-Id: <20220607165025.011233989@linuxfoundation.org> X-Mailer: git-send-email 2.36.1 In-Reply-To: <20220607165002.659942637@linuxfoundation.org> References: <20220607165002.659942637@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Alexander Aring commit 42252d0d2aa9b94d168241710a761588b3959019 upstream. This patch fixes an invalid read showed by KASAN. A unlock will allocate a "struct plock_op" and a followed send_op() will append it to a global send_list data structure. In some cases a followed dev_read() moves it to recv_list and dev_write() will cast it to "struct plock_xop" and access fields which are only available in those structures. At this point an invalid read happens by accessing those fields. To fix this issue the "callback" field is moved to "struct plock_op" to indicate that a cast to "plock_xop" is allowed and does the additional "plock_xop" handling if set. Example of the KASAN output which showed the invalid read: [ 2064.296453] ================================================================== [ 2064.304852] BUG: KASAN: slab-out-of-bounds in dev_write+0x52b/0x5a0 [dlm] [ 2064.306491] Read of size 8 at addr ffff88800ef227d8 by task dlm_controld/7484 [ 2064.308168] [ 2064.308575] CPU: 0 PID: 7484 Comm: dlm_controld Kdump: loaded Not tainted 5.14.0+ #9 [ 2064.310292] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2011 [ 2064.311618] Call Trace: [ 2064.312218] dump_stack_lvl+0x56/0x7b [ 2064.313150] print_address_description.constprop.8+0x21/0x150 [ 2064.314578] ? dev_write+0x52b/0x5a0 [dlm] [ 2064.315610] ? dev_write+0x52b/0x5a0 [dlm] [ 2064.316595] kasan_report.cold.14+0x7f/0x11b [ 2064.317674] ? dev_write+0x52b/0x5a0 [dlm] [ 2064.318687] dev_write+0x52b/0x5a0 [dlm] [ 2064.319629] ? dev_read+0x4a0/0x4a0 [dlm] [ 2064.320713] ? bpf_lsm_kernfs_init_security+0x10/0x10 [ 2064.321926] vfs_write+0x17e/0x930 [ 2064.322769] ? __fget_light+0x1aa/0x220 [ 2064.323753] ksys_write+0xf1/0x1c0 [ 2064.324548] ? __ia32_sys_read+0xb0/0xb0 [ 2064.325464] do_syscall_64+0x3a/0x80 [ 2064.326387] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 2064.327606] RIP: 0033:0x7f807e4ba96f [ 2064.328470] Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 39 87 f8 ff 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 7c 87 f8 ff 48 [ 2064.332902] RSP: 002b:00007ffd50cfe6e0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 [ 2064.334658] RAX: ffffffffffffffda RBX: 000055cc3886eb30 RCX: 00007f807e4ba96f [ 2064.336275] RDX: 0000000000000040 RSI: 00007ffd50cfe7e0 RDI: 0000000000000010 [ 2064.337980] RBP: 00007ffd50cfe7e0 R08: 0000000000000000 R09: 0000000000000001 [ 2064.339560] R10: 000055cc3886eb30 R11: 0000000000000293 R12: 000055cc3886eb80 [ 2064.341237] R13: 000055cc3886eb00 R14: 000055cc3886f590 R15: 0000000000000001 [ 2064.342857] [ 2064.343226] Allocated by task 12438: [ 2064.344057] kasan_save_stack+0x1c/0x40 [ 2064.345079] __kasan_kmalloc+0x84/0xa0 [ 2064.345933] kmem_cache_alloc_trace+0x13b/0x220 [ 2064.346953] dlm_posix_unlock+0xec/0x720 [dlm] [ 2064.348811] do_lock_file_wait.part.32+0xca/0x1d0 [ 2064.351070] fcntl_setlk+0x281/0xbc0 [ 2064.352879] do_fcntl+0x5e4/0xfe0 [ 2064.354657] __x64_sys_fcntl+0x11f/0x170 [ 2064.356550] do_syscall_64+0x3a/0x80 [ 2064.358259] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 2064.360745] [ 2064.361511] Last potentially related work creation: [ 2064.363957] kasan_save_stack+0x1c/0x40 [ 2064.365811] __kasan_record_aux_stack+0xaf/0xc0 [ 2064.368100] call_rcu+0x11b/0xf70 [ 2064.369785] dlm_process_incoming_buffer+0x47d/0xfd0 [dlm] [ 2064.372404] receive_from_sock+0x290/0x770 [dlm] [ 2064.374607] process_recv_sockets+0x32/0x40 [dlm] [ 2064.377290] process_one_work+0x9a8/0x16e0 [ 2064.379357] worker_thread+0x87/0xbf0 [ 2064.381188] kthread+0x3ac/0x490 [ 2064.383460] ret_from_fork+0x22/0x30 [ 2064.385588] [ 2064.386518] Second to last potentially related work creation: [ 2064.389219] kasan_save_stack+0x1c/0x40 [ 2064.391043] __kasan_record_aux_stack+0xaf/0xc0 [ 2064.393303] call_rcu+0x11b/0xf70 [ 2064.394885] dlm_process_incoming_buffer+0x47d/0xfd0 [dlm] [ 2064.397694] receive_from_sock+0x290/0x770 [dlm] [ 2064.399932] process_recv_sockets+0x32/0x40 [dlm] [ 2064.402180] process_one_work+0x9a8/0x16e0 [ 2064.404388] worker_thread+0x87/0xbf0 [ 2064.406124] kthread+0x3ac/0x490 [ 2064.408021] ret_from_fork+0x22/0x30 [ 2064.409834] [ 2064.410599] The buggy address belongs to the object at ffff88800ef22780 [ 2064.410599] which belongs to the cache kmalloc-96 of size 96 [ 2064.416495] The buggy address is located 88 bytes inside of [ 2064.416495] 96-byte region [ffff88800ef22780, ffff88800ef227e0) [ 2064.422045] The buggy address belongs to the page: [ 2064.424635] page:00000000b6bef8bc refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0xef22 [ 2064.428970] flags: 0xfffffc0000200(slab|node=0|zone=1|lastcpupid=0x1fffff) [ 2064.432515] raw: 000fffffc0000200 ffffea0000d68b80 0000001400000014 ffff888001041780 [ 2064.436110] raw: 0000000000000000 0000000080200020 00000001ffffffff 0000000000000000 [ 2064.439813] page dumped because: kasan: bad access detected [ 2064.442548] [ 2064.443310] Memory state around the buggy address: [ 2064.445988] ffff88800ef22680: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 2064.449444] ffff88800ef22700: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 2064.452941] >ffff88800ef22780: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc [ 2064.456383] ^ [ 2064.459386] ffff88800ef22800: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc [ 2064.462788] ffff88800ef22880: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc [ 2064.466239] ================================================================== reproducer in python: import argparse import struct import fcntl import os parser = argparse.ArgumentParser() parser.add_argument('-f', '--file', help='file to use fcntl, must be on dlm lock filesystem e.g. gfs2') args = parser.parse_args() f = open(args.file, 'wb+') lockdata = struct.pack('hhllhh', fcntl.F_WRLCK,0,0,0,0,0) fcntl.fcntl(f, fcntl.F_SETLK, lockdata) lockdata = struct.pack('hhllhh', fcntl.F_UNLCK,0,0,0,0,0) fcntl.fcntl(f, fcntl.F_SETLK, lockdata) Fixes: 586759f03e2e ("gfs2: nfs lock support for gfs2") Cc: stable@vger.kernel.org Signed-off-by: Andreas Gruenbacher Signed-off-by: Alexander Aring Signed-off-by: David Teigland Signed-off-by: Greg Kroah-Hartman --- fs/dlm/plock.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) --- a/fs/dlm/plock.c +++ b/fs/dlm/plock.c @@ -23,11 +23,11 @@ struct plock_op { struct list_head list; int done; struct dlm_plock_info info; + int (*callback)(struct file_lock *fl, int result); }; struct plock_xop { struct plock_op xop; - int (*callback)(struct file_lock *fl, int result); void *fl; void *file; struct file_lock flc; @@ -129,19 +129,18 @@ int dlm_posix_lock(dlm_lockspace_t *lock /* fl_owner is lockd which doesn't distinguish processes on the nfs client */ op->info.owner = (__u64) fl->fl_pid; - xop->callback = fl->fl_lmops->lm_grant; + op->callback = fl->fl_lmops->lm_grant; locks_init_lock(&xop->flc); locks_copy_lock(&xop->flc, fl); xop->fl = fl; xop->file = file; } else { op->info.owner = (__u64)(long) fl->fl_owner; - xop->callback = NULL; } send_op(op); - if (xop->callback == NULL) { + if (!op->callback) { rv = wait_event_interruptible(recv_wq, (op->done != 0)); if (rv == -ERESTARTSYS) { log_debug(ls, "dlm_posix_lock: wait killed %llx", @@ -203,7 +202,7 @@ static int dlm_plock_callback(struct plo file = xop->file; flc = &xop->flc; fl = xop->fl; - notify = xop->callback; + notify = op->callback; if (op->info.rv) { notify(fl, op->info.rv); @@ -436,10 +435,9 @@ static ssize_t dev_write(struct file *fi if (op->info.fsid == info.fsid && op->info.number == info.number && op->info.owner == info.owner) { - struct plock_xop *xop = (struct plock_xop *)op; list_del_init(&op->list); memcpy(&op->info, &info, sizeof(info)); - if (xop->callback) + if (op->callback) do_callback = 1; else op->done = 1;