md: fix kmemleak of rdev->serial

Message ID 20240208085556.2412922-1-linan666@huaweicloud.com
State New
Headers
Series md: fix kmemleak of rdev->serial |

Commit Message

Li Nan Feb. 8, 2024, 8:55 a.m. UTC
  From: Li Nan <linan122@huawei.com>

If kobject_add() is fail in bind_rdev_to_array(), 'rdev->serial' will be
alloc not be freed, and kmemleak occurs.

unreferenced object 0xffff88815a350000 (size 49152):
  comm "mdadm", pid 789, jiffies 4294716910
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace (crc f773277a):
    [<0000000058b0a453>] kmemleak_alloc+0x61/0xe0
    [<00000000366adf14>] __kmalloc_large_node+0x15e/0x270
    [<000000002e82961b>] __kmalloc_node.cold+0x11/0x7f
    [<00000000f206d60a>] kvmalloc_node+0x74/0x150
    [<0000000034bf3363>] rdev_init_serial+0x67/0x170
    [<0000000010e08fe9>] mddev_create_serial_pool+0x62/0x220
    [<00000000c3837bf0>] bind_rdev_to_array+0x2af/0x630
    [<0000000073c28560>] md_add_new_disk+0x400/0x9f0
    [<00000000770e30ff>] md_ioctl+0x15bf/0x1c10
    [<000000006cfab718>] blkdev_ioctl+0x191/0x3f0
    [<0000000085086a11>] vfs_ioctl+0x22/0x60
    [<0000000018b656fe>] __x64_sys_ioctl+0xba/0xe0
    [<00000000e54e675e>] do_syscall_64+0x71/0x150
    [<000000008b0ad622>] entry_SYSCALL_64_after_hwframe+0x6c/0x74

Fixes: 963c555e75b0 ("md: introduce mddev_create/destroy_wb_pool for the change of member device")
Signed-off-by: Li Nan <linan122@huawei.com>
---
 drivers/md/md.c | 1 +
 1 file changed, 1 insertion(+)
  

Comments

Song Liu Feb. 12, 2024, 11:23 p.m. UTC | #1
On Thu, Feb 8, 2024 at 1:00 AM <linan666@huaweicloud.com> wrote:
>
> From: Li Nan <linan122@huawei.com>
>
> If kobject_add() is fail in bind_rdev_to_array(), 'rdev->serial' will be
> alloc not be freed, and kmemleak occurs.
>
> unreferenced object 0xffff88815a350000 (size 49152):
>   comm "mdadm", pid 789, jiffies 4294716910
>   hex dump (first 32 bytes):
>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>     00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
>   backtrace (crc f773277a):
>     [<0000000058b0a453>] kmemleak_alloc+0x61/0xe0
>     [<00000000366adf14>] __kmalloc_large_node+0x15e/0x270
>     [<000000002e82961b>] __kmalloc_node.cold+0x11/0x7f
>     [<00000000f206d60a>] kvmalloc_node+0x74/0x150
>     [<0000000034bf3363>] rdev_init_serial+0x67/0x170
>     [<0000000010e08fe9>] mddev_create_serial_pool+0x62/0x220
>     [<00000000c3837bf0>] bind_rdev_to_array+0x2af/0x630
>     [<0000000073c28560>] md_add_new_disk+0x400/0x9f0
>     [<00000000770e30ff>] md_ioctl+0x15bf/0x1c10
>     [<000000006cfab718>] blkdev_ioctl+0x191/0x3f0
>     [<0000000085086a11>] vfs_ioctl+0x22/0x60
>     [<0000000018b656fe>] __x64_sys_ioctl+0xba/0xe0
>     [<00000000e54e675e>] do_syscall_64+0x71/0x150
>     [<000000008b0ad622>] entry_SYSCALL_64_after_hwframe+0x6c/0x74
>
> Fixes: 963c555e75b0 ("md: introduce mddev_create/destroy_wb_pool for the change of member device")
> Signed-off-by: Li Nan <linan122@huawei.com>

LGTM. Applied to md-6.9.

Thanks,
Song
  

Patch

diff --git a/drivers/md/md.c b/drivers/md/md.c
index e05858653a41..350f5b22ba6f 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2536,6 +2536,7 @@  static int bind_rdev_to_array(struct md_rdev *rdev, struct mddev *mddev)
  fail:
 	pr_warn("md: failed to register dev-%s for %s\n",
 		b, mdname(mddev));
+	mddev_destroy_serial_pool(mddev, rdev);
 	return err;
 }