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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: linux-kernel@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	stable@vger.kernel.org,
	syzbot+1e46a0864c1a6e9bd3d8@syzkaller.appspotmail.com,
	"Dae R. Jeong" <dae.r.jeong@kaist.ac.kr>,
	Song Liu <songliubraving@fb.com>
Subject: [PATCH 5.10 40/40] md: fix a warning caused by a race between concurrent md_ioctl()s
Date: Wed, 23 Dec 2020 16:33:41 +0100	[thread overview]
Message-ID: <20201223150517.462984079@linuxfoundation.org> (raw)
In-Reply-To: <20201223150515.553836647@linuxfoundation.org>

From: Dae R. Jeong <dae.r.jeong@kaist.ac.kr>

commit c731b84b51bf7fe83448bea8f56a6d55006b0615 upstream.

Syzkaller reports a warning as belows.
WARNING: CPU: 0 PID: 9647 at drivers/md/md.c:7169
...
Call Trace:
...
RIP: 0010:md_ioctl+0x4017/0x5980 drivers/md/md.c:7169
RSP: 0018:ffff888096027950 EFLAGS: 00010293
RAX: ffff88809322c380 RBX: 0000000000000932 RCX: ffffffff84e266f2
RDX: 0000000000000000 RSI: ffffffff84e299f7 RDI: 0000000000000007
RBP: ffff888096027bc0 R08: ffff88809322c380 R09: ffffed101341a482
R10: ffff888096027940 R11: ffff88809a0d240f R12: 0000000000000932
R13: ffff8880a2c14100 R14: ffff88809a0d2268 R15: ffff88809a0d2408
 __blkdev_driver_ioctl block/ioctl.c:304 [inline]
 blkdev_ioctl+0xece/0x1c10 block/ioctl.c:606
 block_ioctl+0xee/0x130 fs/block_dev.c:1930
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0xd5f/0x1380 fs/ioctl.c:696
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0xfd/0x680 arch/x86/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

This is caused by a race between two concurrenct md_ioctl()s closing
the array.
CPU1 (md_ioctl())                   CPU2 (md_ioctl())
------                              ------
set_bit(MD_CLOSING, &mddev->flags);
did_set_md_closing = true;
                                    WARN_ON_ONCE(test_bit(MD_CLOSING,
                                            &mddev->flags));
if(did_set_md_closing)
    clear_bit(MD_CLOSING, &mddev->flags);

Fix the warning by returning immediately if the MD_CLOSING bit is set
in &mddev->flags which indicates that the array is being closed.

Fixes: 065e519e71b2 ("md: MD_CLOSING needs to be cleared after called md_set_readonly or do_md_stop")
Reported-by: syzbot+1e46a0864c1a6e9bd3d8@syzkaller.appspotmail.com
Cc: stable@vger.kernel.org
Signed-off-by: Dae R. Jeong <dae.r.jeong@kaist.ac.kr>
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/md/md.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -7590,8 +7590,11 @@ static int md_ioctl(struct block_device
 			err = -EBUSY;
 			goto out;
 		}
-		WARN_ON_ONCE(test_bit(MD_CLOSING, &mddev->flags));
-		set_bit(MD_CLOSING, &mddev->flags);
+		if (test_and_set_bit(MD_CLOSING, &mddev->flags)) {
+			mutex_unlock(&mddev->open_mutex);
+			err = -EBUSY;
+			goto out;
+		}
 		did_set_md_closing = true;
 		mutex_unlock(&mddev->open_mutex);
 		sync_blockdev(bdev);



  parent reply	other threads:[~2020-12-23 15:35 UTC|newest]

Thread overview: 60+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-23 15:33 [PATCH 5.10 00/40] 5.10.3-rc1 review Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 01/40] net: ipconfig: Avoid spurious blank lines in boot log Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 02/40] x86/split-lock: Avoid returning with interrupts enabled Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 03/40] exfat: Avoid allocating upcase table using kcalloc() Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 04/40] soc/tegra: fuse: Fix index bug in get_process_id Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 05/40] usb: mtu3: fix memory corruption in mtu3_debugfs_regset() Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 06/40] USB: serial: option: add interface-number sanity check to flag handling Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 07/40] USB: gadget: f_acm: add support for SuperSpeed Plus Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 08/40] USB: gadget: f_midi: setup SuperSpeed Plus descriptors Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 09/40] usb: gadget: f_fs: Re-use SS descriptors for SuperSpeedPlus Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 10/40] USB: gadget: f_rndis: fix bitrate for SuperSpeed and above Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 11/40] usb: chipidea: ci_hdrc_imx: Pass DISABLE_DEVICE_STREAMING flag to imx6ul Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 12/40] ARM: dts: exynos: fix roles of USB 3.0 ports on Odroid XU Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 13/40] ARM: dts: exynos: fix USB 3.0 VBUS control and over-current pins on Exynos5410 Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 14/40] ARM: dts: exynos: fix USB 3.0 pins supply being turned off on Odroid XU Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 15/40] coresight: tmc-etf: Fix NULL ptr dereference in tmc_enable_etf_sink_perf() Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 16/40] coresight: tmc-etr: Check if page is valid before dma_map_page() Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 17/40] coresight: tmc-etr: Fix barrier packet insertion for perf buffer Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 18/40] coresight: etb10: Fix possible NULL ptr dereference in etb_enable_perf() Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 19/40] coresight: etm4x: Skip setting LPOVERRIDE bit for qcom, skip-power-up Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 20/40] coresight: etm4x: Fix accesses to TRCVMIDCTLR1 Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 21/40] coresight: etm4x: Fix accesses to TRCCIDCTLR1 Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 22/40] coresight: etm4x: Fix accesses to TRCPROCSELR Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 23/40] coresight: etm4x: Handle TRCVIPCSSCTLR accesses Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 24/40] f2fs: fix to seek incorrect data offset in inline data file Greg Kroah-Hartman
2020-12-24  1:11   ` Chao Yu
2020-12-24  7:52     ` Greg Kroah-Hartman
2020-12-24  9:38       ` Chao Yu
2020-12-23 15:33 ` [PATCH 5.10 25/40] f2fs: init dirty_secmap incorrectly Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 26/40] scsi: megaraid_sas: Check user-provided offsets Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 27/40] HID: i2c-hid: add Vero K147 to descriptor override Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 28/40] serial_core: Check for port state when tty is in error state Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 29/40] fscrypt: remove kernel-internal constants from UAPI header Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 30/40] fscrypt: add fscrypt_is_nokey_name() Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 31/40] ubifs: prevent creating duplicate encrypted filenames Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 32/40] ext4: " Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 33/40] f2fs: " Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 34/40] Bluetooth: Fix slab-out-of-bounds read in hci_le_direct_adv_report_evt() Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 35/40] quota: Sanity-check quota file headers on load Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 36/40] fs: quota: fix array-index-out-of-bounds bug by passing correct argument to vfs_cleanup_quota_inode() Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 37/40] media: msi2500: assign SPI bus number dynamically Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 38/40] crypto: af_alg - avoid undefined behavior accessing salg_name Greg Kroah-Hartman
2020-12-23 15:33 ` [PATCH 5.10 39/40] nl80211: validate key indexes for cfg80211_registered_device Greg Kroah-Hartman
2020-12-23 15:33 ` Greg Kroah-Hartman [this message]
2020-12-24  0:56 ` [PATCH 5.10 00/40] 5.10.3-rc1 review Daniel Díaz
2020-12-26 15:07   ` Greg Kroah-Hartman
2020-12-24  9:43 ` Jeffrin Jose T
2020-12-26 15:06   ` Greg Kroah-Hartman
2020-12-27 15:50     ` Jeffrin Jose T
2020-12-27 16:05       ` Greg Kroah-Hartman
2020-12-27 21:33         ` Jeffrin Jose T
2020-12-28  9:50           ` Pavel Machek
2020-12-28 20:41             ` Guenter Roeck
2021-01-03 13:07               ` Jeffrin Jose T
2021-01-04  6:21                 ` Greg Kroah-Hartman
2021-01-06 19:38                   ` Jeffrin Jose T
2021-01-06 19:49                     ` Greg Kroah-Hartman
2021-01-06 23:56                       ` Jeffrin Jose T
2020-12-24 15:26 ` Guenter Roeck
2020-12-26 15:06   ` Greg Kroah-Hartman

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