diff mbox series

[v1] f2fs: fix NULL pointer dereference in f2fs_submit_page_write()

Message ID 20240116141138.1245-1-qwjhust@gmail.com
State New
Headers
Series [v1] f2fs: fix NULL pointer dereference in f2fs_submit_page_write() |

Commit Message

Wenjie Qi Jan. 16, 2024, 2:11 p.m. UTC 
  BUG: kernel NULL pointer dereference, address: 0000000000000014
RIP: 0010:f2fs_submit_page_write+0x6cf/0x780 [f2fs]
Call Trace:
<TASK>
? show_regs+0x6e/0x80
? __die+0x29/0x70
? page_fault_oops+0x154/0x4a0
? prb_read_valid+0x20/0x30
? __irq_work_queue_local+0x39/0xd0
? irq_work_queue+0x36/0x70
? do_user_addr_fault+0x314/0x6c0
? exc_page_fault+0x7d/0x190
? asm_exc_page_fault+0x2b/0x30
? f2fs_submit_page_write+0x6cf/0x780 [f2fs]
? f2fs_submit_page_write+0x736/0x780 [f2fs]
do_write_page+0x50/0x170 [f2fs]
f2fs_outplace_write_data+0x61/0xb0 [f2fs]
f2fs_do_write_data_page+0x3f8/0x660 [f2fs]
f2fs_write_single_data_page+0x5bb/0x7a0 [f2fs]
f2fs_write_cache_pages+0x3da/0xbe0 [f2fs]
..
It is possible that other threads have added this fio to io->bio
and submitted the io->bio before entering f2fs_submit_page_write().
At this point io->bio = NULL.
If is_end_zone_blkaddr(sbi, fio->new_blkaddr) of this fio is true,
then an NULL pointer dereference error occurs at bio_get(io->bio).
The original code for determining zone end was after "out:",
which would have missed some fio who is zone end. I've moved
 this code before "skip:" to make sure it's done for each fio.

Signed-off-by: Wenjie Qi <qwjhust@gmail.com>
---
 fs/f2fs/data.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

Comments

Daeho Jeong Jan. 16, 2024, 9:58 p.m. UTC | #1 
On Tue, Jan 16, 2024 at 6:13 AM Wenjie Qi <qwjhust@gmail.com> wrote:
>
> BUG: kernel NULL pointer dereference, address: 0000000000000014
> RIP: 0010:f2fs_submit_page_write+0x6cf/0x780 [f2fs]
> Call Trace:
> <TASK>
> ? show_regs+0x6e/0x80
> ? __die+0x29/0x70
> ? page_fault_oops+0x154/0x4a0
> ? prb_read_valid+0x20/0x30
> ? __irq_work_queue_local+0x39/0xd0
> ? irq_work_queue+0x36/0x70
> ? do_user_addr_fault+0x314/0x6c0
> ? exc_page_fault+0x7d/0x190
> ? asm_exc_page_fault+0x2b/0x30
> ? f2fs_submit_page_write+0x6cf/0x780 [f2fs]
> ? f2fs_submit_page_write+0x736/0x780 [f2fs]
> do_write_page+0x50/0x170 [f2fs]
> f2fs_outplace_write_data+0x61/0xb0 [f2fs]
> f2fs_do_write_data_page+0x3f8/0x660 [f2fs]
> f2fs_write_single_data_page+0x5bb/0x7a0 [f2fs]
> f2fs_write_cache_pages+0x3da/0xbe0 [f2fs]
> ...
> It is possible that other threads have added this fio to io->bio
> and submitted the io->bio before entering f2fs_submit_page_write().
> At this point io->bio = NULL.
> If is_end_zone_blkaddr(sbi, fio->new_blkaddr) of this fio is true,
> then an NULL pointer dereference error occurs at bio_get(io->bio).
> The original code for determining zone end was after "out:",
> which would have missed some fio who is zone end. I've moved
>  this code before "skip:" to make sure it's done for each fio.
>
> Signed-off-by: Wenjie Qi <qwjhust@gmail.com>
> ---
>  fs/f2fs/data.c | 8 ++++----
>  1 file changed, 4 insertions(+), 4 deletions(-)
>
> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> index dce8defdf4c7..4f445906db8b 100644
> --- a/fs/f2fs/data.c
> +++ b/fs/f2fs/data.c
> @@ -1080,10 +1080,6 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio)
>         io->last_block_in_bio = fio->new_blkaddr;
>
>         trace_f2fs_submit_page_write(fio->page, fio);
> -skip:
> -       if (fio->in_list)
> -               goto next;
> -out:
>  #ifdef CONFIG_BLK_DEV_ZONED
>         if (f2fs_sb_has_blkzoned(sbi) && btype < META &&
>                         is_end_zone_blkaddr(sbi, fio->new_blkaddr)) {
> @@ -1096,6 +1092,10 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio)
>                 __submit_merged_bio(io);
>         }
>  #endif
> +skip:
> +       if (fio->in_list)
> +               goto next;
> +out:

How about moving only the "out" label instead of the whole block from
"skip" to "out"?

>         if (is_sbi_flag_set(sbi, SBI_IS_SHUTDOWN) ||
>                                 !f2fs_is_checkpoint_ready(sbi))
>                 __submit_merged_bio(io);
> --
> 2.34.1
>
>
>
> _______________________________________________
> Linux-f2fs-devel mailing list
> Linux-f2fs-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
Wenjie Qi Jan. 17, 2024, 1:39 a.m. UTC | #2 
Hello Daeho,
I don't think moving just the "out" label will work.
If a fio is zone end and in_list = 1, that fio is missed without being judged.

On Wed, Jan 17, 2024 at 5:58 AM Daeho Jeong <daeho43@gmail.com> wrote:
>
> On Tue, Jan 16, 2024 at 6:13 AM Wenjie Qi <qwjhust@gmail.com> wrote:
> >
> > BUG: kernel NULL pointer dereference, address: 0000000000000014
> > RIP: 0010:f2fs_submit_page_write+0x6cf/0x780 [f2fs]
> > Call Trace:
> > <TASK>
> > ? show_regs+0x6e/0x80
> > ? __die+0x29/0x70
> > ? page_fault_oops+0x154/0x4a0
> > ? prb_read_valid+0x20/0x30
> > ? __irq_work_queue_local+0x39/0xd0
> > ? irq_work_queue+0x36/0x70
> > ? do_user_addr_fault+0x314/0x6c0
> > ? exc_page_fault+0x7d/0x190
> > ? asm_exc_page_fault+0x2b/0x30
> > ? f2fs_submit_page_write+0x6cf/0x780 [f2fs]
> > ? f2fs_submit_page_write+0x736/0x780 [f2fs]
> > do_write_page+0x50/0x170 [f2fs]
> > f2fs_outplace_write_data+0x61/0xb0 [f2fs]
> > f2fs_do_write_data_page+0x3f8/0x660 [f2fs]
> > f2fs_write_single_data_page+0x5bb/0x7a0 [f2fs]
> > f2fs_write_cache_pages+0x3da/0xbe0 [f2fs]
> > ...
> > It is possible that other threads have added this fio to io->bio
> > and submitted the io->bio before entering f2fs_submit_page_write().
> > At this point io->bio = NULL.
> > If is_end_zone_blkaddr(sbi, fio->new_blkaddr) of this fio is true,
> > then an NULL pointer dereference error occurs at bio_get(io->bio).
> > The original code for determining zone end was after "out:",
> > which would have missed some fio who is zone end. I've moved
> >  this code before "skip:" to make sure it's done for each fio.
> >
> > Signed-off-by: Wenjie Qi <qwjhust@gmail.com>
> > ---
> >  fs/f2fs/data.c | 8 ++++----
> >  1 file changed, 4 insertions(+), 4 deletions(-)
> >
> > diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> > index dce8defdf4c7..4f445906db8b 100644
> > --- a/fs/f2fs/data.c
> > +++ b/fs/f2fs/data.c
> > @@ -1080,10 +1080,6 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio)
> >         io->last_block_in_bio = fio->new_blkaddr;
> >
> >         trace_f2fs_submit_page_write(fio->page, fio);
> > -skip:
> > -       if (fio->in_list)
> > -               goto next;
> > -out:
> >  #ifdef CONFIG_BLK_DEV_ZONED
> >         if (f2fs_sb_has_blkzoned(sbi) && btype < META &&
> >                         is_end_zone_blkaddr(sbi, fio->new_blkaddr)) {
> > @@ -1096,6 +1092,10 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio)
> >                 __submit_merged_bio(io);
> >         }
> >  #endif
> > +skip:
> > +       if (fio->in_list)
> > +               goto next;
> > +out:
>
> How about moving only the "out" label instead of the whole block from
> "skip" to "out"?
>
> >         if (is_sbi_flag_set(sbi, SBI_IS_SHUTDOWN) ||
> >                                 !f2fs_is_checkpoint_ready(sbi))
> >                 __submit_merged_bio(io);
> > --
> > 2.34.1
> >
> >
> >
> > _______________________________________________
> > Linux-f2fs-devel mailing list
> > Linux-f2fs-devel@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
Yongpeng Yang Jan. 17, 2024, 10:17 a.m. UTC | #3 
Hello Wenjie,
This patch does not prevent the simultaneous truth of 
list_empty(&io->io_list), fio->in_list, and is_end_zone_blkaddr(sbi, 
fio->new_blkaddr). NULL pointer dereference error still exists in 
“bio_get(io->bio)”. Is that correct?

On 1/17/2024 9:39 AM, Wenjie Qi wrote:
> Hello Daeho,
> I don't think moving just the "out" label will work.
> If a fio is zone end and in_list = 1, that fio is missed without being judged.
> 
> On Wed, Jan 17, 2024 at 5:58 AM Daeho Jeong <daeho43@gmail.com> wrote:
>>
>> On Tue, Jan 16, 2024 at 6:13 AM Wenjie Qi <qwjhust@gmail.com> wrote:
>>>
>>> BUG: kernel NULL pointer dereference, address: 0000000000000014
>>> RIP: 0010:f2fs_submit_page_write+0x6cf/0x780 [f2fs]
>>> Call Trace:
>>> <TASK>
>>> ? show_regs+0x6e/0x80
>>> ? __die+0x29/0x70
>>> ? page_fault_oops+0x154/0x4a0
>>> ? prb_read_valid+0x20/0x30
>>> ? __irq_work_queue_local+0x39/0xd0
>>> ? irq_work_queue+0x36/0x70
>>> ? do_user_addr_fault+0x314/0x6c0
>>> ? exc_page_fault+0x7d/0x190
>>> ? asm_exc_page_fault+0x2b/0x30
>>> ? f2fs_submit_page_write+0x6cf/0x780 [f2fs]
>>> ? f2fs_submit_page_write+0x736/0x780 [f2fs]
>>> do_write_page+0x50/0x170 [f2fs]
>>> f2fs_outplace_write_data+0x61/0xb0 [f2fs]
>>> f2fs_do_write_data_page+0x3f8/0x660 [f2fs]
>>> f2fs_write_single_data_page+0x5bb/0x7a0 [f2fs]
>>> f2fs_write_cache_pages+0x3da/0xbe0 [f2fs]
>>> ...
>>> It is possible that other threads have added this fio to io->bio
>>> and submitted the io->bio before entering f2fs_submit_page_write().
>>> At this point io->bio = NULL.
>>> If is_end_zone_blkaddr(sbi, fio->new_blkaddr) of this fio is true,
>>> then an NULL pointer dereference error occurs at bio_get(io->bio).
>>> The original code for determining zone end was after "out:",
>>> which would have missed some fio who is zone end. I've moved
>>>   this code before "skip:" to make sure it's done for each fio.
>>>
>>> Signed-off-by: Wenjie Qi <qwjhust@gmail.com>
>>> ---
>>>   fs/f2fs/data.c | 8 ++++----
>>>   1 file changed, 4 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
>>> index dce8defdf4c7..4f445906db8b 100644
>>> --- a/fs/f2fs/data.c
>>> +++ b/fs/f2fs/data.c
>>> @@ -1080,10 +1080,6 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio)
>>>          io->last_block_in_bio = fio->new_blkaddr;
>>>
>>>          trace_f2fs_submit_page_write(fio->page, fio);
>>> -skip:
>>> -       if (fio->in_list)
>>> -               goto next;
>>> -out:
>>>   #ifdef CONFIG_BLK_DEV_ZONED
>>>          if (f2fs_sb_has_blkzoned(sbi) && btype < META &&
>>>                          is_end_zone_blkaddr(sbi, fio->new_blkaddr)) {
>>> @@ -1096,6 +1092,10 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio)
>>>                  __submit_merged_bio(io);
>>>          }
>>>   #endif
>>> +skip:
>>> +       if (fio->in_list)
>>> +               goto next;
>>> +out:
>>
>> How about moving only the "out" label instead of the whole block from
>> "skip" to "out"?
>>
>>>          if (is_sbi_flag_set(sbi, SBI_IS_SHUTDOWN) ||
>>>                                  !f2fs_is_checkpoint_ready(sbi))
>>>                  __submit_merged_bio(io);
>>> --
>>> 2.34.1
>>>
>>>
>>>
>>> _______________________________________________
>>> Linux-f2fs-devel mailing list
>>> Linux-f2fs-devel@lists.sourceforge.net
>>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> 
> 
> _______________________________________________
> Linux-f2fs-devel mailing list
> Linux-f2fs-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
Wenjie Qi Jan. 17, 2024, 11:27 a.m. UTC | #4 
Hello Yongpeng,
I don't think that's correct.
If list_empty(&io->io_list) and fio->in_list are true, it will jump to
the "out" label. This does not enter the judgment process.
In addition,  __bio_alloc() will ensure that io->bio ! = NULL.

On Wed, Jan 17, 2024 at 6:17 PM Yongpeng Yang <yangyongpeng1@oppo.com> wrote:
>
> Hello Wenjie,
> This patch does not prevent the simultaneous truth of
> list_empty(&io->io_list), fio->in_list, and is_end_zone_blkaddr(sbi,
> fio->new_blkaddr). NULL pointer dereference error still exists in
> “bio_get(io->bio)”. Is that correct?
>
> On 1/17/2024 9:39 AM, Wenjie Qi wrote:
> > Hello Daeho,
> > I don't think moving just the "out" label will work.
> > If a fio is zone end and in_list = 1, that fio is missed without being judged.
> >
> > On Wed, Jan 17, 2024 at 5:58 AM Daeho Jeong <daeho43@gmail.com> wrote:
> >>
> >> On Tue, Jan 16, 2024 at 6:13 AM Wenjie Qi <qwjhust@gmail.com> wrote:
> >>>
> >>> BUG: kernel NULL pointer dereference, address: 0000000000000014
> >>> RIP: 0010:f2fs_submit_page_write+0x6cf/0x780 [f2fs]
> >>> Call Trace:
> >>> <TASK>
> >>> ? show_regs+0x6e/0x80
> >>> ? __die+0x29/0x70
> >>> ? page_fault_oops+0x154/0x4a0
> >>> ? prb_read_valid+0x20/0x30
> >>> ? __irq_work_queue_local+0x39/0xd0
> >>> ? irq_work_queue+0x36/0x70
> >>> ? do_user_addr_fault+0x314/0x6c0
> >>> ? exc_page_fault+0x7d/0x190
> >>> ? asm_exc_page_fault+0x2b/0x30
> >>> ? f2fs_submit_page_write+0x6cf/0x780 [f2fs]
> >>> ? f2fs_submit_page_write+0x736/0x780 [f2fs]
> >>> do_write_page+0x50/0x170 [f2fs]
> >>> f2fs_outplace_write_data+0x61/0xb0 [f2fs]
> >>> f2fs_do_write_data_page+0x3f8/0x660 [f2fs]
> >>> f2fs_write_single_data_page+0x5bb/0x7a0 [f2fs]
> >>> f2fs_write_cache_pages+0x3da/0xbe0 [f2fs]
> >>> ...
> >>> It is possible that other threads have added this fio to io->bio
> >>> and submitted the io->bio before entering f2fs_submit_page_write().
> >>> At this point io->bio = NULL.
> >>> If is_end_zone_blkaddr(sbi, fio->new_blkaddr) of this fio is true,
> >>> then an NULL pointer dereference error occurs at bio_get(io->bio).
> >>> The original code for determining zone end was after "out:",
> >>> which would have missed some fio who is zone end. I've moved
> >>>   this code before "skip:" to make sure it's done for each fio.
> >>>
> >>> Signed-off-by: Wenjie Qi <qwjhust@gmail.com>
> >>> ---
> >>>   fs/f2fs/data.c | 8 ++++----
> >>>   1 file changed, 4 insertions(+), 4 deletions(-)
> >>>
> >>> diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
> >>> index dce8defdf4c7..4f445906db8b 100644
> >>> --- a/fs/f2fs/data.c
> >>> +++ b/fs/f2fs/data.c
> >>> @@ -1080,10 +1080,6 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio)
> >>>          io->last_block_in_bio = fio->new_blkaddr;
> >>>
> >>>          trace_f2fs_submit_page_write(fio->page, fio);
> >>> -skip:
> >>> -       if (fio->in_list)
> >>> -               goto next;
> >>> -out:
> >>>   #ifdef CONFIG_BLK_DEV_ZONED
> >>>          if (f2fs_sb_has_blkzoned(sbi) && btype < META &&
> >>>                          is_end_zone_blkaddr(sbi, fio->new_blkaddr)) {
> >>> @@ -1096,6 +1092,10 @@ void f2fs_submit_page_write(struct f2fs_io_info *fio)
> >>>                  __submit_merged_bio(io);
> >>>          }
> >>>   #endif
> >>> +skip:
> >>> +       if (fio->in_list)
> >>> +               goto next;
> >>> +out:
> >>
> >> How about moving only the "out" label instead of the whole block from
> >> "skip" to "out"?
> >>
> >>>          if (is_sbi_flag_set(sbi, SBI_IS_SHUTDOWN) ||
> >>>                                  !f2fs_is_checkpoint_ready(sbi))
> >>>                  __submit_merged_bio(io);
> >>> --
> >>> 2.34.1
> >>>
> >>>
> >>>
> >>> _______________________________________________
> >>> Linux-f2fs-devel mailing list
> >>> Linux-f2fs-devel@lists.sourceforge.net
> >>> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
> >
> >
> > _______________________________________________
> > Linux-f2fs-devel mailing list
> > Linux-f2fs-devel@lists.sourceforge.net
> > https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
Chao Yu Jan. 29, 2024, 10:27 a.m. UTC | #5 
On 2024/1/16 22:11, Wenjie Qi wrote:
> BUG: kernel NULL pointer dereference, address: 0000000000000014
> RIP: 0010:f2fs_submit_page_write+0x6cf/0x780 [f2fs]
> Call Trace:
> <TASK>
> ? show_regs+0x6e/0x80
> ? __die+0x29/0x70
> ? page_fault_oops+0x154/0x4a0
> ? prb_read_valid+0x20/0x30
> ? __irq_work_queue_local+0x39/0xd0
> ? irq_work_queue+0x36/0x70
> ? do_user_addr_fault+0x314/0x6c0
> ? exc_page_fault+0x7d/0x190
> ? asm_exc_page_fault+0x2b/0x30
> ? f2fs_submit_page_write+0x6cf/0x780 [f2fs]
> ? f2fs_submit_page_write+0x736/0x780 [f2fs]
> do_write_page+0x50/0x170 [f2fs]
> f2fs_outplace_write_data+0x61/0xb0 [f2fs]
> f2fs_do_write_data_page+0x3f8/0x660 [f2fs]
> f2fs_write_single_data_page+0x5bb/0x7a0 [f2fs]
> f2fs_write_cache_pages+0x3da/0xbe0 [f2fs]
> ...
> It is possible that other threads have added this fio to io->bio
> and submitted the io->bio before entering f2fs_submit_page_write().
> At this point io->bio = NULL.
> If is_end_zone_blkaddr(sbi, fio->new_blkaddr) of this fio is true,
> then an NULL pointer dereference error occurs at bio_get(io->bio).
> The original code for determining zone end was after "out:",
> which would have missed some fio who is zone end. I've moved
>   this code before "skip:" to make sure it's done for each fio.
> 
> Signed-off-by: Wenjie Qi <qwjhust@gmail.com>

Reviewed-by: Chao Yu <chao@kernel.org>

Thanks,
Chao Yu Jan. 29, 2024, 11:16 a.m. UTC | #6 
On 2024/1/29 18:27, Chao Yu wrote:
> On 2024/1/16 22:11, Wenjie Qi wrote:
>> BUG: kernel NULL pointer dereference, address: 0000000000000014
>> RIP: 0010:f2fs_submit_page_write+0x6cf/0x780 [f2fs]
>> Call Trace:
>> <TASK>
>> ? show_regs+0x6e/0x80
>> ? __die+0x29/0x70
>> ? page_fault_oops+0x154/0x4a0
>> ? prb_read_valid+0x20/0x30
>> ? __irq_work_queue_local+0x39/0xd0
>> ? irq_work_queue+0x36/0x70
>> ? do_user_addr_fault+0x314/0x6c0
>> ? exc_page_fault+0x7d/0x190
>> ? asm_exc_page_fault+0x2b/0x30
>> ? f2fs_submit_page_write+0x6cf/0x780 [f2fs]
>> ? f2fs_submit_page_write+0x736/0x780 [f2fs]
>> do_write_page+0x50/0x170 [f2fs]
>> f2fs_outplace_write_data+0x61/0xb0 [f2fs]
>> f2fs_do_write_data_page+0x3f8/0x660 [f2fs]
>> f2fs_write_single_data_page+0x5bb/0x7a0 [f2fs]
>> f2fs_write_cache_pages+0x3da/0xbe0 [f2fs]
>> ...
>> It is possible that other threads have added this fio to io->bio
>> and submitted the io->bio before entering f2fs_submit_page_write().
>> At this point io->bio = NULL.
>> If is_end_zone_blkaddr(sbi, fio->new_blkaddr) of this fio is true,
>> then an NULL pointer dereference error occurs at bio_get(io->bio).
>> The original code for determining zone end was after "out:",
>> which would have missed some fio who is zone end. I've moved
>>   this code before "skip:" to make sure it's done for each fio.
>>

Fixes: e067dc3c6b9c ("f2fs: maintain six open zones for zoned devices")

>> Signed-off-by: Wenjie Qi <qwjhust@gmail.com>
> 
> Reviewed-by: Chao Yu <chao@kernel.org>
> 
> Thanks,
> 
> 
> _______________________________________________
> Linux-f2fs-devel mailing list
> Linux-f2fs-devel@lists.sourceforge.net
> https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
patchwork-bot+f2fs@kernel.org Jan. 29, 2024, 8:29 p.m. UTC | #7 
Hello:

This patch was applied to jaegeuk/f2fs.git (dev)
by Jaegeuk Kim <jaegeuk@kernel.org>:

On Tue, 16 Jan 2024 22:11:38 +0800 you wrote:
> BUG: kernel NULL pointer dereference, address: 0000000000000014
> RIP: 0010:f2fs_submit_page_write+0x6cf/0x780 [f2fs]
> Call Trace:
> <TASK>
> ? show_regs+0x6e/0x80
> ? __die+0x29/0x70
> ? page_fault_oops+0x154/0x4a0
> ? prb_read_valid+0x20/0x30
> ? __irq_work_queue_local+0x39/0xd0
> ? irq_work_queue+0x36/0x70
> ? do_user_addr_fault+0x314/0x6c0
> ? exc_page_fault+0x7d/0x190
> ? asm_exc_page_fault+0x2b/0x30
> ? f2fs_submit_page_write+0x6cf/0x780 [f2fs]
> ? f2fs_submit_page_write+0x736/0x780 [f2fs]
> do_write_page+0x50/0x170 [f2fs]
> f2fs_outplace_write_data+0x61/0xb0 [f2fs]
> f2fs_do_write_data_page+0x3f8/0x660 [f2fs]
> f2fs_write_single_data_page+0x5bb/0x7a0 [f2fs]
> f2fs_write_cache_pages+0x3da/0xbe0 [f2fs]
> ...
> It is possible that other threads have added this fio to io->bio
> and submitted the io->bio before entering f2fs_submit_page_write().
> At this point io->bio = NULL.
> If is_end_zone_blkaddr(sbi, fio->new_blkaddr) of this fio is true,
> then an NULL pointer dereference error occurs at bio_get(io->bio).
> The original code for determining zone end was after "out:",
> which would have missed some fio who is zone end. I've moved
>  this code before "skip:" to make sure it's done for each fio.
> 
> [...]

Here is the summary with links:
  - [f2fs-dev,v1] f2fs: fix NULL pointer dereference in f2fs_submit_page_write()
    https://git.kernel.org/jaegeuk/f2fs/c/52434fdc4f86

You are awesome, thank you!
diff mbox series

Patch

diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c
index dce8defdf4c7..4f445906db8b 100644
--- a/fs/f2fs/data.c
+++ b/fs/f2fs/data.c
@@ -1080,10 +1080,6 @@  void f2fs_submit_page_write(struct f2fs_io_info *fio)
 	io->last_block_in_bio = fio->new_blkaddr;
 
 	trace_f2fs_submit_page_write(fio->page, fio);
-skip:
-	if (fio->in_list)
-		goto next;
-out:
 #ifdef CONFIG_BLK_DEV_ZONED
 	if (f2fs_sb_has_blkzoned(sbi) && btype < META &&
 			is_end_zone_blkaddr(sbi, fio->new_blkaddr)) {
@@ -1096,6 +1092,10 @@  void f2fs_submit_page_write(struct f2fs_io_info *fio)
 		__submit_merged_bio(io);
 	}
 #endif
+skip:
+	if (fio->in_list)
+		goto next;
+out:
 	if (is_sbi_flag_set(sbi, SBI_IS_SHUTDOWN) ||
 				!f2fs_is_checkpoint_ready(sbi))
 		__submit_merged_bio(io);