From: Pedro Fonseca <pfonseca@mpi-sws.org>
To: bo.li.liu@oracle.com
Cc: linux-btrfs@vger.kernel.org
Subject: Re: Null pointer dereference bug in btrfs_find_all_root
Date: Tue, 29 Oct 2013 04:38:39 +0100 [thread overview]
Message-ID: <526F2DBF.4090404@mpi-sws.org> (raw)
In-Reply-To: <20131029020554.GA32338@localhost.localdomain>
On 10/29/13 3:05 AM, Liu Bo wrote:
> Hi,
>
> On Mon, Oct 28, 2013 at 05:02:11PM +0100, Pedro Fonseca wrote:
>> Hi,
>>
>> I've encountered a few NULL pointer dereference bugs while running a
>> custom test case on btrfs (kernel 3.11.1), inside a QEMU based VM.
>>
>> Btrfs was statically compiled and the btrfs filesystem was mounted
>> on one or two loop devices. All cases occurred during execution of a
>> "filesystem balance" operation and while another file system
>> operation was concurrently executed. In one case the other operation
>> was a "mknod" and in another it was a "filesystem show" operation.
> I'm wonderring that if there is anything like 'aborted transaction' in
> the dmesg log besides this NULL pointer dereference?
>
> -liubo
No, I didn't find any references to aborted transactions. But I did get
a message about "relocation of block groups" and a few other messages
caused by resizing operations.
These are all the filesystem messages I got before the actual bug report:
[ 111.836409] loop: module loaded
[ 112.939586] device fsid acb9f83e-75d7-4177-9f7b-4b7c8e0f53d9 devid 1
transid 7 /dev/loop0
[ 122.328339] btrfs: new size for /dev/loop0 is 311427072
[ 122.396188] btrfs: new size for /dev/loop0 is 301989888
[ 122.646333] btrfs: new size for /dev/loop0 is 299892736
[ 127.788383] btrfs: new size for /dev/loop0 is 305135616
[ 127.830656] btrfs: relocating block group 20971520 flags 1
>> In all cases the NULL pointer dereference occurred in the
>> "btrfs_find_all_roots" function and all cases produced a bug report
>> similar to the one bellow:
>>
>>> [ 138.573390] BUG: unable to handle kernel NULL pointer
>>> dereference at (null)
>>> [ 138.573390] IP: [<c12feeb3>] ulist_next+0x4/0x26
>>> [ 138.573390] *pde = 00000000
>>> [ 138.573390] Oops: 0000 [#1] SMP
>>> [ 138.573390] Modules linked in: loop rtc_cmos pcspkr tpm_tis
>>> freq_table mperf i2c_piix4
>>> [ 138.573390] CPU: 0 PID: 2794 Comm: btrfs-endio-wri Not tainted
>>> 3.11.1 #2
>>> [ 138.573390] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
>>> [ 138.573390] task: c5dea6b0 ti: c5e12000 task.ti: c5e12000
>>> [ 138.573390] EIP: 0060:[<c12feeb3>] EFLAGS: 00000246 CPU: 0
>>> [ 138.573390] EIP is at ulist_next+0x4/0x26
>>> [ 138.573390] EAX: 00000000 EBX: 00000000 ECX: d9c29e38 EDX: c5e13da4
>>> [ 138.573390] ESI: 00000000 EDI: c5e13e00 EBP: c5e13d94 ESP: c5e13d90
>>> [ 138.573390] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
>>> [ 138.573390] CR0: 8005003b CR2: 00000000 CR3: 059d8000 CR4: 00000690
>>> [ 138.573390] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
>>> [ 138.573390] DR6: 00000000 DR7: 00000000
>>> [ 138.573390] Stack:
>>> [ 138.573390] 00000000 c5e13db4 c12fe7b8 de4d1000 d9cead48
>>> 00000001 010dd000 deeab810
>>> [ 138.573390] 00000001 c5e13e10 c12fe8cf 00af2000 00000000
>>> 00000000 00000003 c5e13e00
>>> [ 138.573390] deeabe00 00000000 00000003 deeab800 de4d1000
>>> d9cead48 de4d14b8 de4d14b8
>>> [ 138.573390] Call Trace:
>>> [ 138.573390] [<c12fe7b8>] btrfs_find_all_roots+0x88/0xa6
>>> [ 138.573390] [<c12fe8cf>] iterate_extent_inodes+0xf9/0x1b2
>>> [ 138.573390] [<c12feba9>] iterate_inodes_from_logical+0x88/0x97
>>> [ 138.573390] [<c12b8880>] ? record_extent_backrefs+0x8b/0x8b
>>> [ 138.573390] [<c12b8845>] record_extent_backrefs+0x50/0x8b
>>> [ 138.573390] [<c12b8880>] ? record_extent_backrefs+0x8b/0x8b
>>> [ 138.573390] [<c12c1f8e>] btrfs_finish_ordered_io+0x77e/0x876
>>> [ 138.573390] [<c12c2091>] finish_ordered_fn+0xb/0xd
>>> [ 138.573390] [<c12db161>] worker_loop+0x111/0x3ec
>>> [ 138.573390] [<c104a2c4>] ? default_wake_function+0xb/0xd
>>> [ 138.573390] [<c1040c43>] kthread+0x90/0x95
>>> [ 138.573390] [<c12db050>] ? btrfs_queue_worker+0x1c8/0x1c8
>>> [ 138.573390] [<c176c277>] ret_from_kernel_thread+0x1b/0x28
>>> [ 138.573390] [<c1040bb3>] ? kthread_freezable_should_stop+0x4f/0x4f
>>> [ 138.573390] Code: 5b 5e 5f 5d c3 90 90 90 55 8d 50 10 89 e5 c7
>>> 00 00 00 00 00 89 50 08 c7 40 04 10 00 00 00 c7 40 0c 00 00 00 00
>>> 5d c3 55 89 e5 53 <8b> 08 85 c9 74 15 8b 1a 85 db 78 0f 39 cb 73
>>> 0b 6b cb 1c 43 03
>>> [ 138.573390] EIP: [<c12feeb3>] ulist_next+0x4/0x26 SS:ESP 0068:c5e13d90
>>> [ 138.573390] CR2: 0000000000000000
>>> [ 138.573390] ---[ end trace 626899e11111abbe ]---
>>> [ 138.573390] BUG: unable to handle kernel NULL pointer
>>> dereference at (null)
>>> [ 138.573390] IP: [<c12feeb3>] ulist_next+0x4/0x26
>>> [ 138.573390] *pde = 00000000
>>> [ 138.573390] Oops: 0000 [#2] SMP
>>> [ 138.573390] Modules linked in: loop rtc_cmos pcspkr tpm_tis
>>> freq_table mperf i2c_piix4
>>> [ 138.573390] CPU: 1 PID: 2793 Comm: btrfs-endio-wri Tainted: G
>>> D 3.11.1 #2
>>> [ 138.573390] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007
>>> [ 138.573390] task: c59cc190 ti: dedc8000 task.ti: dedc8000
>>> [ 138.573390] EIP: 0060:[<c12feeb3>] EFLAGS: 00000246 CPU: 1
>>> [ 138.573390] EIP is at ulist_next+0x4/0x26
>>> [ 138.573390] EAX: 00000000 EBX: 00000000 ECX: d9c296c8 EDX: dedc9da4
>>> [ 138.573390] ESI: 00000000 EDI: dedc9e00 EBP: dedc9d94 ESP: dedc9d90
>>> [ 138.573390] DS: 007b ES: 007b FS: 00d8 GS: 0000 SS: 0068
>>> [ 138.573390] CR0: 8005003b CR2: 00000000 CR3: 03ebe000 CR4: 00000690
>>> [ 138.573390] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
>>> [ 138.573390] DR6: 00000000 DR7: 00000000
>>> [ 138.573390] Stack:
>>> [ 138.573390] 00000000 dedc9db4 c12fe7b8 de4d1000 d9ceaf50
>>> 00000001 00dea000 de4c6410
>>> [ 138.573390] 00000001 dedc9e10 c12fe8cf 00af2000 00000000
>>> 00000000 00000005 dedc9e00
>>> [ 138.573390] de4c6c00 00000000 00000005 de4c6400 de4d1000
>>> d9ceaf50 de4d14b8 c5e13de8
>>> [ 138.573390] Call Trace:
>>> [ 138.573390] [<c12fe7b8>] btrfs_find_all_roots+0x88/0xa6
>>> [ 138.573390] [<c12fe8cf>] iterate_extent_inodes+0xf9/0x1b2
>>> [ 138.573390] [<c12feba9>] iterate_inodes_from_logical+0x88/0x97
>>> [ 138.573390] [<c12b8880>] ? record_extent_backrefs+0x8b/0x8b
>>> [ 138.573390] [<c12b8845>] record_extent_backrefs+0x50/0x8b
>>> [ 138.573390] [<c12b8880>] ? record_extent_backrefs+0x8b/0x8b
>>> [ 138.573390] [<c12c1f8e>] btrfs_finish_ordered_io+0x77e/0x876
>>> [ 138.573390] [<c12c2091>] finish_ordered_fn+0xb/0xd
>>> [ 138.573390] [<c12db161>] worker_loop+0x111/0x3ec
>>> [ 138.573390] [<c104a2c4>] ? default_wake_function+0xb/0xd
>>> [ 138.573390] [<c1040c43>] kthread+0x90/0x95
>>> [ 138.573390] [<c12db050>] ? btrfs_queue_worker+0x1c8/0x1c8
>>> [ 138.573390] [<c176c277>] ret_from_kernel_thread+0x1b/0x28
>>> [ 138.573390] [<c1040bb3>] ? kthread_freezable_should_stop+0x4f/0x4f
>>> [ 138.573390] Code: 5b 5e 5f 5d c3 90 90 90 55 8d 50 10 89 e5 c7
>>> 00 00 00 00 00 89 50 08 c7 40 04 10 00 00 00 c7 40 0c 00 00 00 00
>>> 5d c3 55 89 e5 53 <8b> 08 85 c9 74 15 8b 1a 85 db 78 0f 39 cb 73
>>> 0b 6b cb 1c 43 03
>>> [ 138.573390] EIP: [<c12feeb3>] ulist_next+0x4/0x26 SS:ESP 0068:dedc9d90
>>> [ 138.573390] CR2: 0000000000000000
>>> [ 138.573390] ---[ end trace 626899e11111abbf ]---
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next prev parent reply other threads:[~2013-10-29 3:38 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-10-28 16:02 Null pointer dereference bug in btrfs_find_all_root Pedro Fonseca
2013-10-29 2:05 ` Liu Bo
2013-10-29 3:38 ` Pedro Fonseca [this message]
2013-10-29 6:17 ` Liu Bo
2013-10-29 13:40 ` Pedro Fonseca
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