From patchwork Mon Nov 11 09:28:26 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Thumshirn X-Patchwork-Id: 13870460 Received: from mail-wm1-f48.google.com (mail-wm1-f48.google.com [209.85.128.48]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EE158170A30 for ; Mon, 11 Nov 2024 09:28:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.48 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731317322; cv=none; b=dQnPpOyQTlP8ZxqIgfxdoIB85LoCqUL6DCkJwCMdTn00yD+fugelgiiXq+sMPYtu9FHCB97r0gm1fB8nowimIs4hZaL2BJ2EPTX3kTkikuLmd1Ib9PaL+Wg3cai3/idGb3yJa1UkLA8etLGLD6+Z6X+8NJ/yY5igOdUSM1bW+44= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731317322; c=relaxed/simple; bh=qIZ8JnNnfX+0hPASvGLXboMYi4IMTcKCYJanJCD26Vs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=pXaK0QChsBsEm1mhNlTJC0riZ5wsXaiu/4PiiuI8+mrKxcYW5odqgrv6YwUYdrIIQEqO8hcj93Roy4DE3dqus+bwWC5w4TbrGytfgUmj/y2UaTkl3UX5ipv2uROAx+PERyfXUJOKVuUguOmrK1Hg/hd1V1p7u6eeR7njP5szL9U= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=kernel.org; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=209.85.128.48 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=kernel.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-wm1-f48.google.com with SMTP id 5b1f17b1804b1-43193678216so40890795e9.0 for ; Mon, 11 Nov 2024 01:28:40 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1731317319; x=1731922119; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=JAWjAXPnqX68CPoYkseo6GXN9CxCZSjHhMHUI8Lr1v8=; b=pNTP6MVnaJUYt5dhRwPnhjJtQjxZMss8Kj1wJ/NPwJUTNAywnC6IwcDuduwScmIQp+ +b+0GL5WL3wfV+MMfC+JK9ta5EEHmkZMH00Oyp5UHKKj8k3tX8Elndv13/pLORdRF6KD d0KlGBFLe0wegmFcCRBBVJrh+wtpVEAAODHLw+KnCIZDkNQgZYtvkjqvzmDDfOJUc++H rMRl7mjrsZ61RfqJGZFmVKkK5/bzV5PfZhAxIxeJfar5LInBNCsaBNaZRyUO/cgtcwxI IyWPS2v+1qpYG6TKsgxxha8F7wWhah0gu21T5ftn+xi51+n2MC7A5ne5NYEgXNz55PSx Gqxw== X-Gm-Message-State: AOJu0Yylna6dZZQuGKEYN1wVxVWC4XCeOmt+/CTl6LuNqVDvC2qR1wke 5zacNmclEkyFR64NdjJ+R0yTil9KEugsqUDJDwpNe6yhD7LWMKv9nJXI9w== X-Google-Smtp-Source: AGHT+IEBXHxnUqTWKGrgHVP6tPVewXF2mITAnBVTQJZpDPZyMFgzruB+8NMqethmUd+CISu6ng5gtg== X-Received: by 2002:a05:600c:5124:b0:431:46fe:4cad with SMTP id 5b1f17b1804b1-432b7501d4emr106025695e9.9.1731317318958; Mon, 11 Nov 2024 01:28:38 -0800 (PST) Received: from nuc.fritz.box (p200300f6f71fdb00fa633ffffe02074c.dip0.t-ipconnect.de. [2003:f6:f71f:db00:fa63:3fff:fe02:74c]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-432b05c202asm173711505e9.30.2024.11.11.01.28.38 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 Nov 2024 01:28:38 -0800 (PST) From: Johannes Thumshirn To: linux-btrfs@vger.kernel.org Cc: Damien Le Moal , Johannes Thumshirn , Mark Harmstone , Omar Sandoval , Shinichiro Kawasaki , Damien Le Moal Subject: [PATCH 1/2] btrfs: fix use-after-free in btrfs_encoded_read_endio Date: Mon, 11 Nov 2024 10:28:26 +0100 Message-ID: <88ede763421d4f9847a057bdc944cb9c684e8cae.1731316882.git.jth@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Johannes Thumshirn Shinichiro reported the following use-after free that sometimes is happening in our CI system when running fstests' btrfs/284 on a TCMU runner device: ================================================================== BUG: KASAN: slab-use-after-free in lock_release+0x708/0x780 Read of size 8 at addr ffff888106a83f18 by task kworker/u80:6/219 CPU: 8 UID: 0 PID: 219 Comm: kworker/u80:6 Not tainted 6.12.0-rc6-kts+ #15 Hardware name: Supermicro Super Server/X11SPi-TF, BIOS 3.3 02/21/2020 Workqueue: btrfs-endio btrfs_end_bio_work [btrfs] Call Trace: dump_stack_lvl+0x6e/0xa0 ? lock_release+0x708/0x780 print_report+0x174/0x505 ? lock_release+0x708/0x780 ? __virt_addr_valid+0x224/0x410 ? lock_release+0x708/0x780 kasan_report+0xda/0x1b0 ? lock_release+0x708/0x780 ? __wake_up+0x44/0x60 lock_release+0x708/0x780 ? __pfx_lock_release+0x10/0x10 ? __pfx_do_raw_spin_lock+0x10/0x10 ? lock_is_held_type+0x9a/0x110 _raw_spin_unlock_irqrestore+0x1f/0x60 __wake_up+0x44/0x60 btrfs_encoded_read_endio+0x14b/0x190 [btrfs] btrfs_check_read_bio+0x8d9/0x1360 [btrfs] ? lock_release+0x1b0/0x780 ? trace_lock_acquire+0x12f/0x1a0 ? __pfx_btrfs_check_read_bio+0x10/0x10 [btrfs] ? process_one_work+0x7e3/0x1460 ? lock_acquire+0x31/0xc0 ? process_one_work+0x7e3/0x1460 process_one_work+0x85c/0x1460 ? __pfx_process_one_work+0x10/0x10 ? assign_work+0x16c/0x240 worker_thread+0x5e6/0xfc0 ? __pfx_worker_thread+0x10/0x10 kthread+0x2c3/0x3a0 ? __pfx_kthread+0x10/0x10 ret_from_fork+0x31/0x70 ? __pfx_kthread+0x10/0x10 ret_from_fork_asm+0x1a/0x30 Allocated by task 3661: kasan_save_stack+0x30/0x50 kasan_save_track+0x14/0x30 __kasan_kmalloc+0xaa/0xb0 btrfs_encoded_read_regular_fill_pages+0x16c/0x6d0 [btrfs] send_extent_data+0xf0f/0x24a0 [btrfs] process_extent+0x48a/0x1830 [btrfs] changed_cb+0x178b/0x2ea0 [btrfs] btrfs_ioctl_send+0x3bf9/0x5c20 [btrfs] _btrfs_ioctl_send+0x117/0x330 [btrfs] btrfs_ioctl+0x184a/0x60a0 [btrfs] __x64_sys_ioctl+0x12e/0x1a0 do_syscall_64+0x95/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e Freed by task 3661: kasan_save_stack+0x30/0x50 kasan_save_track+0x14/0x30 kasan_save_free_info+0x3b/0x70 __kasan_slab_free+0x4f/0x70 kfree+0x143/0x490 btrfs_encoded_read_regular_fill_pages+0x531/0x6d0 [btrfs] send_extent_data+0xf0f/0x24a0 [btrfs] process_extent+0x48a/0x1830 [btrfs] changed_cb+0x178b/0x2ea0 [btrfs] btrfs_ioctl_send+0x3bf9/0x5c20 [btrfs] _btrfs_ioctl_send+0x117/0x330 [btrfs] btrfs_ioctl+0x184a/0x60a0 [btrfs] __x64_sys_ioctl+0x12e/0x1a0 do_syscall_64+0x95/0x180 entry_SYSCALL_64_after_hwframe+0x76/0x7e The buggy address belongs to the object at ffff888106a83f00 which belongs to the cache kmalloc-rnd-07-96 of size 96 The buggy address is located 24 bytes inside of freed 96-byte region [ffff888106a83f00, ffff888106a83f60) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888106a83800 pfn:0x106a83 flags: 0x17ffffc0000000(node=0|zone=2|lastcpupid=0x1fffff) page_type: f5(slab) raw: 0017ffffc0000000 ffff888100053680 ffffea0004917200 0000000000000004 raw: ffff888106a83800 0000000080200019 00000001f5000000 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff888106a83e00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888106a83e80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc >ffff888106a83f00: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff888106a83f80: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff888106a84000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== Further analyzing the trace and the crash dump's vmcore file shows that the wake_up() call in btrfs_encoded_read_endio() is calling wake_up() on the wait_queue that is in the private data passed to the end_io handler. Commit 4ff47df40447 ("btrfs: move priv off stack in btrfs_encoded_read_regular_fill_pages()") moved 'struct btrfs_encoded_read_private' off the stack. Before that commit one can see a corruption of the private data when analyzing the vmcore after a crash: *(struct btrfs_encoded_read_private *)0xffff88815626eec8 = { .wait = (wait_queue_head_t){ .lock = (spinlock_t){ .rlock = (struct raw_spinlock){ .raw_lock = (arch_spinlock_t){ .val = (atomic_t){ .counter = (int)-2005885696, }, .locked = (u8)0, .pending = (u8)157, .locked_pending = (u16)40192, .tail = (u16)34928, }, .magic = (unsigned int)536325682, .owner_cpu = (unsigned int)29, .owner = (void *)__SCT__tp_func_btrfs_transaction_commit+0x0 = 0x0, .dep_map = (struct lockdep_map){ .key = (struct lock_class_key *)0xffff8881575a3b6c, .class_cache = (struct lock_class *[2]){ 0xffff8882a71985c0, 0xffffea00066f5d40 }, .name = (const char *)0xffff88815626f100 = "", .wait_type_outer = (u8)37, .wait_type_inner = (u8)178, .lock_type = (u8)154, }, }, .__padding = (u8 [24]){ 0, 157, 112, 136, 50, 174, 247, 31, 29 }, .dep_map = (struct lockdep_map){ .key = (struct lock_class_key *)0xffff8881575a3b6c, .class_cache = (struct lock_class *[2]){ 0xffff8882a71985c0, 0xffffea00066f5d40 }, .name = (const char *)0xffff88815626f100 = "", .wait_type_outer = (u8)37, .wait_type_inner = (u8)178, .lock_type = (u8)154, }, }, .head = (struct list_head){ .next = (struct list_head *)0x112cca, .prev = (struct list_head *)0x47, }, }, .pending = (atomic_t){ .counter = (int)-1491499288, }, .status = (blk_status_t)130, } Move the call to bio_put() before the atomic_test operation and also change atomic_dec_return() to atomic_dec_and_test() to fix the corruption, as atomic_dec_return() is defined as two instructions on x86_64, whereas atomic_dec_and_test() is defineda s a single atomic operation. Reported-by: Shinichiro Kawasaki Suggested-by: Damien Le Moal Fixes: 1881fba89bd5 ("btrfs: add BTRFS_IOC_ENCODED_READ ioctl") Signed-off-by: Johannes Thumshirn Reviewed-by: Mark Harmstone --- fs/btrfs/inode.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 22b8e2764619..cb8b23a3e56b 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -9089,7 +9089,8 @@ static void btrfs_encoded_read_endio(struct btrfs_bio *bbio) */ WRITE_ONCE(priv->status, bbio->bio.bi_status); } - if (atomic_dec_return(&priv->pending) == 0) { + bio_put(&bbio->bio); + if (atomic_dec_and_test(&priv->pending)) { int err = blk_status_to_errno(READ_ONCE(priv->status)); if (priv->uring_ctx) { @@ -9099,7 +9100,6 @@ static void btrfs_encoded_read_endio(struct btrfs_bio *bbio) wake_up(&priv->wait); } } - bio_put(&bbio->bio); } int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode, From patchwork Mon Nov 11 09:28:27 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Johannes Thumshirn X-Patchwork-Id: 13870461 Received: from mail-wm1-f54.google.com (mail-wm1-f54.google.com [209.85.128.54]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A2C151553AB for ; Mon, 11 Nov 2024 09:28:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.54 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731317323; cv=none; b=l2j9fF6IYY1NDOgeFjc8yjd7uZfTl76zrB+YZFmEQQSGY/K1fmoeJyskQIY73Nc49oEFhbD24Nr2suOaPYvSB2relPD1ag86XAt8dicoj22bEkxf+ORKlu7wXe/cgwJP5piABH5NfgTf8FKrnZezlZhLhpAXwvSP6sR3pMioIZ0= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731317323; c=relaxed/simple; bh=c2x7qal3yovR0rUMs48xNVcE8vGoUHygiOqg/EdAugk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Rk9cQoUG52UOHJAdj77mqOQ1NDDZpNNrwJsuODLk4Fp66mCkbzNQAZLAHQmuCQJm+beNmMSySefxY8SPpfuWwpI8C/bIHvducemb8J0tvAiYWAJ6R4GNe8LANtjwWBBHvxf+5qewkKFVyMn6t44Rgb+gGzG65UTuzFpwoKVtQGg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=kernel.org; spf=pass smtp.mailfrom=gmail.com; arc=none smtp.client-ip=209.85.128.54 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=kernel.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-wm1-f54.google.com with SMTP id 5b1f17b1804b1-43167ff0f91so37604775e9.1 for ; Mon, 11 Nov 2024 01:28:41 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1731317320; x=1731922120; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=3PfmCXdSTFO6/rEm+dGC66+lP9B/rpowz2PMIhLnd8k=; b=Ahr97kUeI1afIYP/0Bsaqft6+qsUxrIl1+rGjpGvm/8TOWiQ47g4E+b1fbVCIe6+Ni p1HGMz32HDTBQNoq8kf5hi4+K5fuGldrmSE/xNDP3Ria8hNCwI9BHQgFhFczGV1GLLjA TdnSfoGTtS9ztzwxjFKCiH4y/EP4WdEm7rfbYv4XmhX1KEtEzxLmYmcEPq+NuWbM52bx qr5Py8WHJKabiD++g/tVwlojxyttnUDEzWaxKCZYfN4GjXuMkJ2uSCholO40wCdP5ia7 UnGtF/zfF2jX36A1OFNfSRssvBdIMd+J8nW5Q6euWbQWFQ5QZ9+gbtiJYPlCbqItRm0R U6Sg== X-Gm-Message-State: AOJu0YzCSlcb0pua6zfpQp/AgsISu+tQ20RugA1ayVyfWFld/LwcWzuF b1jTI0MyQzy+m1a8rrqmhwF0bmOuQpTFlJY3clz0QhGraGPj63NcJV01ag== X-Google-Smtp-Source: AGHT+IGDybBo4x6fTrQTGF9jqDz6RUOiOInjUo0XBd5oeqoCYuwb4IxobEAkiWBrjt0NpBM14362kg== X-Received: by 2002:a05:600c:1392:b0:431:53db:3d29 with SMTP id 5b1f17b1804b1-432b750a281mr106677715e9.18.1731317319788; Mon, 11 Nov 2024 01:28:39 -0800 (PST) Received: from nuc.fritz.box (p200300f6f71fdb00fa633ffffe02074c.dip0.t-ipconnect.de. [2003:f6:f71f:db00:fa63:3fff:fe02:74c]) by smtp.gmail.com with ESMTPSA id 5b1f17b1804b1-432b05c202asm173711505e9.30.2024.11.11.01.28.39 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 11 Nov 2024 01:28:39 -0800 (PST) From: Johannes Thumshirn To: linux-btrfs@vger.kernel.org Cc: Damien Le Moal , Johannes Thumshirn , Mark Harmstone , Omar Sandoval , Damien Le Moal Subject: [PATCH 2/2] btrfs: simplify waiting for encoded read endios Date: Mon, 11 Nov 2024 10:28:27 +0100 Message-ID: <22c7231a2ce9c0c7c187dff159be1c868d783765.1731316882.git.jth@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-btrfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 From: Johannes Thumshirn Simplifiy the I/O completion path for encoded reads by using a completion instead of a wait_queue. Furthermore skip taking an extra reference that is instantly dropped anyways. Suggested-by: Damien Le Moal Signed-off-by: Johannes Thumshirn --- fs/btrfs/inode.c | 12 +++++------- 1 file changed, 5 insertions(+), 7 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index cb8b23a3e56b..916c9d7ca112 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -9068,7 +9068,7 @@ static ssize_t btrfs_encoded_read_inline( } struct btrfs_encoded_read_private { - wait_queue_head_t wait; + struct completion done; void *uring_ctx; atomic_t pending; blk_status_t status; @@ -9097,7 +9097,7 @@ static void btrfs_encoded_read_endio(struct btrfs_bio *bbio) btrfs_uring_read_extent_endio(priv->uring_ctx, err); kfree(priv); } else { - wake_up(&priv->wait); + complete(&priv->done); } } } @@ -9116,7 +9116,7 @@ int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode, if (!priv) return -ENOMEM; - init_waitqueue_head(&priv->wait); + init_completion(&priv->done); atomic_set(&priv->pending, 1); priv->status = 0; priv->uring_ctx = uring_ctx; @@ -9145,11 +9145,10 @@ int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode, disk_io_size -= bytes; } while (disk_io_size); - atomic_inc(&priv->pending); btrfs_submit_bbio(bbio, 0); if (uring_ctx) { - if (atomic_dec_return(&priv->pending) == 0) { + if (atomic_read(&priv->pending) == 0) { ret = blk_status_to_errno(READ_ONCE(priv->status)); btrfs_uring_read_extent_endio(uring_ctx, ret); kfree(priv); @@ -9158,8 +9157,7 @@ int btrfs_encoded_read_regular_fill_pages(struct btrfs_inode *inode, return -EIOCBQUEUED; } else { - if (atomic_dec_return(&priv->pending) != 0) - io_wait_event(priv->wait, !atomic_read(&priv->pending)); + wait_for_completion(&priv->done); /* See btrfs_encoded_read_endio() for ordering. */ ret = blk_status_to_errno(READ_ONCE(priv->status)); kfree(priv);