From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
stable@vger.kernel.org, Xianting Tian <xianting_tian@126.com>,
Theodore Tso <tytso@mit.edu>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.9 43/78] fs: prevent BUG_ON in submit_bh_wbc()
Date: Tue, 1 Sep 2020 17:10:19 +0200 [thread overview]
Message-ID: <20200901150926.916489149@linuxfoundation.org> (raw)
In-Reply-To: <20200901150924.680106554@linuxfoundation.org>
From: Xianting Tian <xianting_tian@126.com>
[ Upstream commit 377254b2cd2252c7c3151b113cbdf93a7736c2e9 ]
If a device is hot-removed --- for example, when a physical device is
unplugged from pcie slot or a nbd device's network is shutdown ---
this can result in a BUG_ON() crash in submit_bh_wbc(). This is
because the when the block device dies, the buffer heads will have
their Buffer_Mapped flag get cleared, leading to the crash in
submit_bh_wbc.
We had attempted to work around this problem in commit a17712c8
("ext4: check superblock mapped prior to committing"). Unfortunately,
it's still possible to hit the BUG_ON(!buffer_mapped(bh)) if the
device dies between when the work-around check in ext4_commit_super()
and when submit_bh_wbh() is finally called:
Code path:
ext4_commit_super
judge if 'buffer_mapped(sbh)' is false, return <== commit a17712c8
lock_buffer(sbh)
...
unlock_buffer(sbh)
__sync_dirty_buffer(sbh,...
lock_buffer(sbh)
judge if 'buffer_mapped(sbh))' is false, return <== added by this patch
submit_bh(...,sbh)
submit_bh_wbc(...,sbh,...)
[100722.966497] kernel BUG at fs/buffer.c:3095! <== BUG_ON(!buffer_mapped(bh))' in submit_bh_wbc()
[100722.966503] invalid opcode: 0000 [#1] SMP
[100722.966566] task: ffff8817e15a9e40 task.stack: ffffc90024744000
[100722.966574] RIP: 0010:submit_bh_wbc+0x180/0x190
[100722.966575] RSP: 0018:ffffc90024747a90 EFLAGS: 00010246
[100722.966576] RAX: 0000000000620005 RBX: ffff8818a80603a8 RCX: 0000000000000000
[100722.966576] RDX: ffff8818a80603a8 RSI: 0000000000020800 RDI: 0000000000000001
[100722.966577] RBP: ffffc90024747ac0 R08: 0000000000000000 R09: ffff88207f94170d
[100722.966578] R10: 00000000000437c8 R11: 0000000000000001 R12: 0000000000020800
[100722.966578] R13: 0000000000000001 R14: 000000000bf9a438 R15: ffff88195f333000
[100722.966580] FS: 00007fa2eee27700(0000) GS:ffff88203d840000(0000) knlGS:0000000000000000
[100722.966580] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[100722.966581] CR2: 0000000000f0b008 CR3: 000000201a622003 CR4: 00000000007606e0
[100722.966582] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[100722.966583] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[100722.966583] PKRU: 55555554
[100722.966583] Call Trace:
[100722.966588] __sync_dirty_buffer+0x6e/0xd0
[100722.966614] ext4_commit_super+0x1d8/0x290 [ext4]
[100722.966626] __ext4_std_error+0x78/0x100 [ext4]
[100722.966635] ? __ext4_journal_get_write_access+0xca/0x120 [ext4]
[100722.966646] ext4_reserve_inode_write+0x58/0xb0 [ext4]
[100722.966655] ? ext4_dirty_inode+0x48/0x70 [ext4]
[100722.966663] ext4_mark_inode_dirty+0x53/0x1e0 [ext4]
[100722.966671] ? __ext4_journal_start_sb+0x6d/0xf0 [ext4]
[100722.966679] ext4_dirty_inode+0x48/0x70 [ext4]
[100722.966682] __mark_inode_dirty+0x17f/0x350
[100722.966686] generic_update_time+0x87/0xd0
[100722.966687] touch_atime+0xa9/0xd0
[100722.966690] generic_file_read_iter+0xa09/0xcd0
[100722.966694] ? page_cache_tree_insert+0xb0/0xb0
[100722.966704] ext4_file_read_iter+0x4a/0x100 [ext4]
[100722.966707] ? __inode_security_revalidate+0x4f/0x60
[100722.966709] __vfs_read+0xec/0x160
[100722.966711] vfs_read+0x8c/0x130
[100722.966712] SyS_pread64+0x87/0xb0
[100722.966716] do_syscall_64+0x67/0x1b0
[100722.966719] entry_SYSCALL64_slow_path+0x25/0x25
To address this, add the check of 'buffer_mapped(bh)' to
__sync_dirty_buffer(). This also has the benefit of fixing this for
other file systems.
With this addition, we can drop the workaround in ext4_commit_supper().
[ Commit description rewritten by tytso. ]
Signed-off-by: Xianting Tian <xianting_tian@126.com>
Link: https://lore.kernel.org/r/1596211825-8750-1-git-send-email-xianting_tian@126.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
fs/buffer.c | 9 +++++++++
fs/ext4/super.c | 7 -------
2 files changed, 9 insertions(+), 7 deletions(-)
diff --git a/fs/buffer.c b/fs/buffer.c
index a89be9741d125..52f1a60417d1d 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -3203,6 +3203,15 @@ int __sync_dirty_buffer(struct buffer_head *bh, int op_flags)
WARN_ON(atomic_read(&bh->b_count) < 1);
lock_buffer(bh);
if (test_clear_buffer_dirty(bh)) {
+ /*
+ * The bh should be mapped, but it might not be if the
+ * device was hot-removed. Not much we can do but fail the I/O.
+ */
+ if (!buffer_mapped(bh)) {
+ unlock_buffer(bh);
+ return -EIO;
+ }
+
get_bh(bh);
bh->b_end_io = end_buffer_write_sync;
ret = submit_bh(REQ_OP_WRITE, op_flags, bh);
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 370e4273042c5..472fa29c6f604 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -4680,13 +4680,6 @@ static int ext4_commit_super(struct super_block *sb, int sync)
if (!sbh || block_device_ejected(sb))
return error;
- /*
- * The superblock bh should be mapped, but it might not be if the
- * device was hot-removed. Not much we can do but fail the I/O.
- */
- if (!buffer_mapped(sbh))
- return error;
-
/*
* If the file system is mounted read-only, don't update the
* superblock write time. This avoids updating the superblock
--
2.25.1
next prev parent reply other threads:[~2020-09-01 15:16 UTC|newest]
Thread overview: 82+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-01 15:09 [PATCH 4.9 00/78] 4.9.235-rc1 review Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 01/78] bonding: fix a potential double-unregister Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 02/78] bonding: show saner speed for broadcast mode Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 03/78] net: Fix potential wrong skb->protocol in skb_vlan_untag() Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 04/78] tipc: fix uninit skb->data in tipc_nl_compat_dumpit() Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 05/78] ipvlan: fix device features Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 06/78] gre6: Fix reception with IP6_TNL_F_RCV_DSCP_COPY Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 07/78] ALSA: pci: delete repeated words in comments Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 08/78] ASoC: tegra: Fix reference count leaks Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 09/78] arm64: dts: qcom: msm8916: Pull down PDM GPIOs during sleep Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 10/78] media: pci: ttpci: av7110: fix possible buffer overflow caused by bad DMA value in debiirq() Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 11/78] scsi: target: tcmu: Fix crash on ARM during cmd completion Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 12/78] iommu/iova: Dont BUG on invalid PFNs Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 13/78] drm/amdkfd: Fix reference count leaks Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 14/78] drm/radeon: fix multiple reference count leak Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 15/78] drm/amdgpu: fix ref count leak in amdgpu_driver_open_kms Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 16/78] drm/amd/display: fix ref count leak in amdgpu_drm_ioctl Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 17/78] drm/amdgpu: fix ref count leak in amdgpu_display_crtc_set_config Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 18/78] drm/amdgpu/display: fix ref count leak when pm_runtime_get_sync fails Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 19/78] scsi: lpfc: Fix shost refcount mismatch when deleting vport Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 20/78] selftests/powerpc: Purge extra count_pmc() calls of ebb selftests Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 21/78] omapfb: fix multiple reference count leaks due to pm_runtime_get_sync Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 22/78] PCI: Fix pci_create_slot() reference count leak Greg Kroah-Hartman
2020-09-01 15:09 ` [PATCH 4.9 23/78] rtlwifi: rtl8192cu: Prevent leaking urb Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 24/78] mips/vdso: Fix resource leaks in genvdso.c Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 25/78] cec-api: prevent leaking memory through hole in structure Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 26/78] drm/nouveau/drm/noveau: fix reference count leak in nouveau_fbcon_open Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 27/78] drm/nouveau: Fix reference count leak in nouveau_connector_detect Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 28/78] locking/lockdep: Fix overflow in presentation of average lock-time Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 29/78] scsi: iscsi: Do not put host in iscsi_set_flashnode_param() Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 30/78] ceph: fix potential mdsc use-after-free crash Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 31/78] scsi: fcoe: Memory leak fix in fcoe_sysfs_fcf_del() Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 32/78] EDAC/ie31200: Fallback if host bridge device is already initialized Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 33/78] media: davinci: vpif_capture: fix potential double free Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 34/78] KVM: arm64: Fix symbol dependency in __hyp_call_panic_nvhe Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 35/78] powerpc/spufs: add CONFIG_COREDUMP dependency Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 36/78] USB: sisusbvga: Fix a potential UB casued by left shifting a negative value Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 37/78] efi: provide empty efi_enter_virtual_mode implementation Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 38/78] Revert "ath10k: fix DMA related firmware crashes on multiple devices" Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 39/78] i2c: rcar: in slave mode, clear NACK earlier Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 40/78] usb: gadget: f_tcm: Fix some resource leaks in some error paths Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 41/78] jbd2: make sure jh have b_transaction set in refile/unfile_buffer Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 42/78] jbd2: abort journal if free a async write error metadata buffer Greg Kroah-Hartman
2020-09-01 15:10 ` Greg Kroah-Hartman [this message]
2020-09-01 15:10 ` [PATCH 4.9 44/78] s390/cio: add cond_resched() in the slow_eval_known_fn() loop Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 45/78] scsi: ufs: Fix possible infinite loop in ufshcd_hold Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 46/78] scsi: ufs: Improve interrupt handling for shared interrupts Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 47/78] net: gianfar: Add of_node_put() before goto statement Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 48/78] powerpc/perf: Fix soft lockups due to missed interrupt accounting Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 49/78] HID: i2c-hid: Always sleep 60ms after I2C_HID_PWR_ON commands Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 50/78] btrfs: fix space cache memory leak after transaction abort Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 51/78] fbcon: prevent user font height or width change from causing potential out-of-bounds access Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 52/78] USB: lvtest: return proper error code in probe Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 53/78] vt: defer kfree() of vc_screenbuf in vc_do_resize() Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 54/78] vt_ioctl: change VT_RESIZEX ioctl to check for error return from vc_resize() Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 55/78] serial: samsung: Removes the IRQ not found warning Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 56/78] serial: pl011: Fix oops on -EPROBE_DEFER Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 57/78] serial: pl011: Dont leak amba_ports entry on driver register error Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 58/78] serial: 8250: change lock order in serial8250_do_startup() Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 59/78] writeback: Protect inode->i_io_list with inode->i_lock Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 60/78] writeback: Avoid skipping inode writeback Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 61/78] writeback: Fix sync livelock due to b_dirty_time processing Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 62/78] XEN uses irqdesc::irq_data_common::handler_data to store a per interrupt XEN data pointer which contains XEN specific information Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 63/78] xhci: Do warm-reset when both CAS and XDEV_RESUME are set Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 64/78] PM: sleep: core: Fix the handling of pending runtime resume requests Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 65/78] device property: Fix the secondary firmware node handling in set_primary_fwnode() Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 66/78] USB: yurex: Fix bad gfp argument Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 67/78] usb: uas: Add quirk for PNY Pro Elite Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 68/78] USB: quirks: Add no-lpm quirk for another Raydium touchscreen Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 69/78] USB: Ignore UAS for JMicron JMS567 ATA/ATAPI Bridge Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 70/78] usb: host: ohci-exynos: Fix error handling in exynos_ohci_probe() Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 71/78] overflow.h: Add allocation size calculation helpers Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 72/78] USB: gadget: u_f: add overflow checks to VLA macros Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 73/78] USB: gadget: f_ncm: add bounds checks to ncm_unwrap_ntb() Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 74/78] USB: gadget: u_f: Unbreak offset calculation in VLAs Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 75/78] usb: storage: Add unusual_uas entry for Sony PSZ drives Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 76/78] btrfs: check the right error variable in btrfs_del_dir_entries_in_log Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 77/78] HID: hiddev: Fix slab-out-of-bounds write in hiddev_ioctl_usage() Greg Kroah-Hartman
2020-09-01 15:10 ` [PATCH 4.9 78/78] ALSA: usb-audio: Update documentation comment for MS2109 quirk Greg Kroah-Hartman
2020-09-01 22:25 ` [PATCH 4.9 00/78] 4.9.235-rc1 review Shuah Khan
2020-09-02 7:21 ` Naresh Kamboju
2020-09-02 16:46 ` Guenter Roeck
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