From: Yu Kuai yukuai3@huawei.com
mainline inclusion from mainline-v6.2-rc1 commit 077a4033541fc96fb0a955985aab7d1f353da831 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I6B4N7 CVE: NA
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After creating a dm device, then user can reload such dm with itself, and dead loop will be triggered because dm keep looking up to itself.
Test procedures:
1) dmsetup create test --table "xxx sda", assume dm-0 is created 2) dmsetup suspend test 3) dmsetup reload test --table "xxx dm-0" 4) dmsetup resume test
Test result:
BUG: TASK stack guard page was hit at 00000000736a261f (stack is 000000008d12c88d..00000000c8dd82d5) stack guard page: 0000 [#1] PREEMPT SMP CPU: 29 PID: 946 Comm: systemd-udevd Not tainted 6.1.0-rc3-next-20221101-00006-g17640ca3b0ee #1295 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190727_073836-buildvm-ppc64le-16.ppc.fedoraproject.org-3.fc31 04/01/2014 RIP: 0010:dm_prepare_ioctl+0xf/0x1e0 Code: da 48 83 05 4a 7c 99 0b 01 41 89 c4 eb cd e8 b8 1f 40 00 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 57 48 83 05 a1 5a 99 0b 01 <41> 56 49 89 d6 41 55 4c 8d af 90 02 00 00 9 RSP: 0018:ffffc90002090000 EFLAGS: 00010206 RAX: ffff8881049d6800 RBX: ffff88817e589000 RCX: 0000000000000000 RDX: ffffc90002090010 RSI: ffffc9000209001c RDI: ffff88817e589000 RBP: 00000000484a101d R08: 0000000000000000 R09: 0000000000000007 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000005331 R13: 0000000000005331 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fddf9609200(0000) GS:ffff889fbfd40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffc9000208fff8 CR3: 0000000179043000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> dm_blk_ioctl+0x50/0x1c0 ? dm_prepare_ioctl+0xe0/0x1e0 dm_blk_ioctl+0x88/0x1c0 dm_blk_ioctl+0x88/0x1c0 ......(a lot of same lines) dm_blk_ioctl+0x88/0x1c0 dm_blk_ioctl+0x88/0x1c0 blkdev_ioctl+0x184/0x3e0 __x64_sys_ioctl+0xa3/0x110 do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7fddf7306577 Code: b3 66 90 48 8b 05 11 89 2c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d e1 88 8 RSP: 002b:00007ffd0b2ec318 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00005634ef478320 RCX: 00007fddf7306577 RDX: 0000000000000000 RSI: 0000000000005331 RDI: 0000000000000007 RBP: 0000000000000007 R08: 00005634ef4843e0 R09: 0000000000000080 R10: 00007fddf75cfb38 R11: 0000000000000246 R12: 00000000030d4000 R13: 0000000000000000 R14: 0000000000000000 R15: 00005634ef48b800 </TASK> Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:dm_prepare_ioctl+0xf/0x1e0 Code: da 48 83 05 4a 7c 99 0b 01 41 89 c4 eb cd e8 b8 1f 40 00 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 41 57 48 83 05 a1 5a 99 0b 01 <41> 56 49 89 d6 41 55 4c 8d af 90 02 00 00 9 RSP: 0018:ffffc90002090000 EFLAGS: 00010206 RAX: ffff8881049d6800 RBX: ffff88817e589000 RCX: 0000000000000000 RDX: ffffc90002090010 RSI: ffffc9000209001c RDI: ffff88817e589000 RBP: 00000000484a101d R08: 0000000000000000 R09: 0000000000000007 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000005331 R13: 0000000000005331 R14: 0000000000000000 R15: 0000000000000000 FS: 00007fddf9609200(0000) GS:ffff889fbfd40000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffc9000208fff8 CR3: 0000000179043000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Kernel panic - not syncing: Fatal exception in interrupt Kernel Offset: disabled ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]---
Fix the problem by forbidding a disk to create link to itself.
Signed-off-by: Yu Kuai yukuai3@huawei.com Reviewed-by: Christoph Hellwig hch@lst.de Link: https://lore.kernel.org/r/20221115141054.1051801-11-yukuai1@huaweicloud.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Li Lingfeng lilingfeng3@huawei.com Reviewed-by: Yang Erkun yangerkun@huawei.com Reviewed-by: Zhang Yi yi.zhang@huawei.com Signed-off-by: Yongqiang Liu liuyongqiang13@huawei.com --- fs/block_dev.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/fs/block_dev.c b/fs/block_dev.c index 2680092c022d..6ba91b97753f 100644 --- a/fs/block_dev.c +++ b/fs/block_dev.c @@ -1305,6 +1305,8 @@ int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) struct bd_holder_disk *holder; int ret = 0;
+ if (bdev->bd_disk == disk) + return -EINVAL; /* * bdev could be deleted beneath us which would implicitly destroy * the holder directory. Hold on to it.