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Message-ID: <c5bf15c0-932c-5466-3663-92ecebab4760@kernel.org>
Date:   Mon, 22 May 2023 20:44:50 +0800
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Subject: Re: A null-ptr-deref bug in f2fs_write_end_io
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To:     butt3rflyh4ck <butterflyhuangxx@gmail.com>
Cc:     linux-f2fs-devel@lists.sourceforge.net,
        LKML <linux-kernel@vger.kernel.org>,
        Jaegeuk Kim <jaegeuk@kernel.org>
References: <CAFcO6XMJC=u5aASRNCqfVi7tJwDJBYGCw5i13M-R8zXdB9-8Ew@mail.gmail.com>
 <986151e4-66ef-b76d-f66d-318017f34b5d@kernel.org>
 <CAFcO6XNEZVpyPNNuU9X0wub-hrWcfwWX1bP1MT3ggddfgPvmTg@mail.gmail.com>
From:   Chao Yu <chao@kernel.org>
In-Reply-To: <CAFcO6XNEZVpyPNNuU9X0wub-hrWcfwWX1bP1MT3ggddfgPvmTg@mail.gmail.com>
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On 2023/5/22 11:58, butt3rflyh4ck wrote:
> OK, the attachment is a reproducer.

Thank you!

I've figured out a patch, could you please have a try w/ this patch?

https://lore.kernel.org/linux-f2fs-devel/20230522124203.3838360-1-chao@kernel.org/

Thanks,

> 
> Regards.
>   butt3rflyh4ck.
> 
> On Fri, May 19, 2023 at 11:24 PM Chao Yu <chao@kernel.org> wrote:
>>
>> Hi,
>>
>> Thanks for the report, it will be helpful if you can provide a
>> reproducer.
>>
>> On 2023/5/19 15:13, butt3rflyh4ck wrote:
>>> Hi, there is a null-ptr-deref  bug in f2fs_write_end_io in
>>> fs/f2fs/data.c, I reproduce it in the latest kernel too.
>>>
>>> #Quick description
>>> When a thread always calls F2FS_IOC_RESIZE_FS to  resize fs, if resize
>>> fs is failed, f2fs kernel thread would  invoke callback function to
>>> update
>>> f2fs io info, it would call  f2fs_write_end_io and may trigger
>>> null-ptr-deref in NODE_MAPPING.
>>> ```
>>> static inline struct address_space *NODE_MAPPING(struct f2fs_sb_info *sbi)
>>> {
>>> return sbi->node_inode->i_mapping;
>>> }
>>> ```
>>> there is deref in sbi.
>>>
>>> #crash log
>>> ----------------------------------------
>>> general protection fault, probably for non-canonical address
>>> 0xdffffc0000000006: 0000 [#1] PREEMPT SMP KASAN
>>> KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037]
>>> CPU: 0 PID: 17 Comm: ksoftirqd/0 Not tainted 6.4.0-rc1 #18
>>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
>>> RIP: 0010:NODE_MAPPING fs/f2fs/f2fs.h:1972 [inline]
>>> RIP: 0010:f2fs_write_end_io+0x727/0x1050 fs/f2fs/data.c:370
>>> Code: 00 00 48 89 f8 48 c1 e8 03 80 3c 18 00 0f 85 b3 07 00 00 48 8b
>>> 44 24 08 4c 8b a8 60 01 00 00 49 8d 7d 30 48 89 f8 48 c1 e8 03 <80> 3c
>>> 18 00 0f 85 9c 07 00 00 4d 3b 75 30 0f 84 10 04 00 00 e8 10
>>> RSP: 0018:ffffc9000042fc78 EFLAGS: 00010216
>>> RAX: 0000000000000006 RBX: dffffc0000000000 RCX: 0000000000000100
>>> RDX: ffff888013d18000 RSI: ffffffff83a93a4d RDI: 0000000000000030
>>> RBP: ffffea00009e6900 R08: 0000000000000001 R09: 0000000000000000
>>> R10: 0000000000000000 R11: 0000000000000000 R12: ffffea00009e6900
>>> R13: 0000000000000000 R14: ffff88802a3cec48 R15: 0000000000000000
>>> FS:  0000000000000000(0000) GS:ffff88802ca00000(0000) knlGS:0000000000000000
>>> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>> CR2: 0000555faf194000 CR3: 00000000251bd000 CR4: 0000000000750ef0
>>> PKRU: 55555554
>>> Call Trace:
>>>    <TASK>
>>>    bio_endio+0x5af/0x6c0 block/bio.c:1608
>>>    req_bio_endio block/blk-mq.c:761 [inline]
>>>    blk_update_request+0x5cc/0x1690 block/blk-mq.c:906
>>>    blk_mq_end_request+0x59/0x4c0 block/blk-mq.c:1023
>>>    lo_complete_rq+0x1c6/0x280 drivers/block/loop.c:370
>>>    blk_complete_reqs+0xad/0xe0 block/blk-mq.c:1101
>>>    __do_softirq+0x1d4/0x8ef kernel/softirq.c:571
>>>    run_ksoftirqd kernel/softirq.c:939 [inline]
>>>    run_ksoftirqd+0x31/0x60 kernel/softirq.c:931
>>>    smpboot_thread_fn+0x659/0x9e0 kernel/smpboot.c:164
>>>    kthread+0x33e/0x440 kernel/kthread.c:379
>>>    ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
>>>    </TASK>
>>> Modules linked in:
>>> ---[ end trace 0000000000000000 ]---
>>> RIP: 0010:NODE_MAPPING fs/f2fs/f2fs.h:1972 [inline]
>>> RIP: 0010:f2fs_write_end_io+0x727/0x1050 fs/f2fs/data.c:370
>>> Code: 00 00 48 89 f8 48 c1 e8 03 80 3c 18 00 0f 85 b3 07 00 00 48 8b
>>> 44 24 08 4c 8b a8 60 01 00 00 49 8d 7d 30 48 89 f8 48 c1 e8 03 <80> 3c
>>> 18 00 0f 85 9c 07 00 00 4d 3b 75 30 0f 84 10 04 00 00 e8 10
>>> RSP: 0018:ffffc9000042fc78 EFLAGS: 00010216
>>> RAX: 0000000000000006 RBX: dffffc0000000000 RCX: 0000000000000100
>>> RDX: ffff888013d18000 RSI: ffffffff83a93a4d RDI: 0000000000000030
>>> RBP: ffffea00009e6900 R08: 0000000000000001 R09: 0000000000000000
>>> R10: 0000000000000000 R11: 0000000000000000 R12: ffffea00009e6900
>>> R13: 0000000000000000 R14: ffff88802a3cec48 R15: 0000000000000000
>>> FS:  0000000000000000(0000) GS:ffff88802ca00000(0000) knlGS:0000000000000000
>>> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>> CR2: 0000555faf194000 CR3: 00000000251bd000 CR4: 0000000000750ef0
>>> PKRU: 55555554
>>> -----------------------
>>>
>>> # new crash log in latest kernel
>>> ---------------------
>>> [  193.695164][ T8174] loop0: detected capacity change from 0 to 264192
>>> [  193.696467][ T8174] F2FS-fs (loop0): Magic Mismatch,
>>> valid(0xf2f52010) - read(0x0)
>>> [  193.696875][ T8174] F2FS-fs (loop0): Can't find valid F2FS
>>> filesystem in 2th superblock
>>> [  193.698363][ T8174] F2FS-fs (loop0): invalid crc_offset: 0
>>> [  193.700454][ T8174] F2FS-fs (loop0): Disable nat_bits due to
>>> incorrect cp_ver (4542359912962316977, 0)
>>> [  193.716594][ T8174] F2FS-fs (loop0): Try to recover 2th superblock, ret: 0
>>> [  193.717102][ T8174] F2FS-fs (loop0): Mounted with checkpoint
>>> version = 3e17dab1
>>> [  193.743330][ T8174] F2FS-fs (loop0): For resize: curseg of type 0: 46 ==> 4
>>> [  193.743904][ T8174] F2FS-fs (loop0): For resize: curseg of type 3: 52 ==> 6
>>> [  193.745690][ T8174] F2FS-fs (loop0): For resize: curseg of type 4: 50 ==> 8
>>> [  193.746108][ T8174] F2FS-fs (loop0): For resize: curseg of type 5: 48 ==> 10
>>> [  193.751857][ T8174] F2FS-fs (loop0): resize_fs failed, should run
>>> fsck to repair!
>>> [  193.780283][    C0] general protection fault, probably for
>>> non-canonical address 0xdffffc0000000006: 0000 [#1] PREEMPT SMP KASAN
>>> [  193.781027][    C0] KASAN: null-ptr-deref in range
>>> [0x0000000000000030-0x0000000000000037]
>>> [  193.781572][    C0] CPU: 0 PID: 17 Comm: ksoftirqd/0 Not tainted
>>> 6.4.0-rc2-00163-g2d1bcbc6cd70-dirty #17
>>> [  193.782201][    C0] Hardware name: QEMU Standard PC (i440FX + PIIX,
>>> 1996), BIOS 1.15.0-1 04/01/2014
>>> [  193.782727][    C0] RIP: 0010:f2fs_write_end_io+0x727/0x1050
>>> [  193.783083][    C0] Code: 00 00 48 89 f8 48 c1 e8 03 80 3c 18 00 0f
>>> 85 b3 07 00 00 48 8b 44 24 08 4c 8b a8 60 01 00 00 49 8d 7d 30 48 89
>>> f8 48 c1 e8 03 <80> 3c 18 00 0f 85 9c 07 00 00 4d 3b 75 30 0f 0
>>> [  193.784268][    C0] RSP: 0018:ffffc9000042fc78 EFLAGS: 00010216
>>> [  193.784629][    C0] RAX: 0000000000000006 RBX: dffffc0000000000
>>> RCX: 0000000000000100
>>> [  193.785109][    C0] RDX: ffff888013d18000 RSI: ffffffff83a9588d
>>> RDI: 0000000000000030
>>> [  193.785576][    C0] RBP: ffffea000143e740 R08: 0000000000000001
>>> R09: 0000000000000000
>>> [  193.786051][    C0] R10: 0000000000000000 R11: 0000000000000000
>>> R12: ffffea000143e740
>>> [  193.786571][    C0] R13: 0000000000000000 R14: ffff888041423738
>>> R15: 0000000000000000
>>> [  193.787055][    C0] FS:  0000000000000000(0000)
>>> GS:ffff88802ca00000(0000) knlGS:0000000000000000
>>> [  193.787620][    C0] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>> [  193.787997][    C0] CR2: 000056056fd87000 CR3: 000000001b546000
>>> CR4: 00000000000006f0
>>> [  193.788585][    C0] Call Trace:
>>> [  193.788863][    C0]  <TASK>
>>> [  193.789115][    C0]  ? bio_uninit+0x1b7/0x410
>>> [  193.789509][    C0]  ? f2fs_write_end+0xa80/0xa80
>>> [  193.790053][    C0]  bio_endio+0x5af/0x6c0
>>> [  193.790522][    C0]  blk_update_request+0x5cc/0x1690
>>> [  193.791171][    C0]  blk_mq_end_request+0x59/0x4c0
>>> [  193.791695][    C0]  lo_complete_rq+0x1c6/0x280
>>> [  193.792247][    C0]  blk_complete_reqs+0xad/0xe0
>>> [  193.792759][    C0]  __do_softirq+0x1d4/0x8ef
>>> [  193.793312][    C0]  ? __irq_exit_rcu+0x190/0x190
>>> [  193.793805][    C0]  run_ksoftirqd+0x31/0x60
>>> [  193.794183][    C0]  smpboot_thread_fn+0x659/0x9e0
>>> [  193.794576][    C0]  ? sort_range+0x30/0x30
>>> [  193.794900][    C0]  kthread+0x33e/0x440
>>> [  193.795263][    C0]  ? kthread_complete_and_exit+0x40/0x40
>>> [  193.795907][    C0]  ret_from_fork+0x1f/0x30
>>> [  193.796324][    C0]  </TASK>
>>> [  193.796689][    C0] Modules linked in:
>>> [  193.797189][    C0] ---[ end trace 0000000000000000 ]---
>>> [  193.797635][    C0] RIP: 0010:f2fs_write_end_io+0x727/0x1050
>>> [  193.798182][    C0] Code: 00 00 48 89 f8 48 c1 e8 03 80 3c 18 00 0f
>>> 85 b3 07 00 00 48 8b 44 24 08 4c 8b a8 60 01 00 00 49 8d 7d 30 48 89
>>> f8 48 c1 e8 03 <80> 3c 18 00 0f 85 9c 07 00 00 4d 3b 75 30 0f 0
>>> [  193.799559][    C0] RSP: 0018:ffffc9000042fc78 EFLAGS: 00010216
>>> [  193.799945][    C0] RAX: 0000000000000006 RBX: dffffc0000000000
>>> RCX: 0000000000000100
>>> [  193.800329][    C0] RDX: ffff888013d18000 RSI: ffffffff83a9588d
>>> RDI: 0000000000000030
>>> [  193.800666][    C0] RBP: ffffea000143e740 R08: 0000000000000001
>>> R09: 0000000000000000
>>> [  193.801047][    C0] R10: 0000000000000000 R11: 0000000000000000
>>> R12: ffffea000143e740
>>> [  193.801503][    C0] R13: 0000000000000000 R14: ffff888041423738
>>> R15: 0000000000000000
>>> [  193.802069][    C0] FS:  0000000000000000(0000)
>>> GS:ffff88802ca00000(0000) knlGS:0000000000000000
>>> [  193.802804][    C0] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
>>> [  193.803356][    C0] CR2: 000056056fd87000 CR3: 000000001b546000
>>> CR4: 00000000000006f0
>>> [  193.804046][    C0] Kernel panic - not syncing: Fatal exception in interrupt
>>> [  193.804748][    C0] Kernel Offset: disabled
>>> [  193.805086][    C0] Rebooting in 86400 seconds..
>>> ----------------------------
>>>
>>> If needed, I would provide reproduce.
>>>
>>> Regards,
>>>    butt3rflyh4ck.
>>>
>>>
>>>
> 
> 
>