Re: çå: [f2fs-dev] [PATCH] f2fs: relax permission for atomic/volatile ioctls

[gaoxiang (P)]

-----éäåä-----
åää: Jaegeuk Kim [mailto:jaegeuk@xxxxxxxxxx] 
åéæé: 2017å7æ7æ 10:12
æää: gaoxiang (P)
æé: Chao Yu; linux-fsdevel@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx
äé: Re: çå: [f2fs-dev] [PATCH] f2fs: relax permission for atomic/volatile ioctls

On 07/07, gaoxiang (P) wrote:
> Hi,
> I think Sdcardfs should override task_struct cred fsuid/fsgid before calling the underlay fs operation.
> And it seems sdcardfs implementations misses override cred fsuid/fsgid before the ioctl operation.

Oh, good catch!

Thank you. ;)


;) We are fixing it internally. And the AOSP sdcardfs patch would be
https://android-review.googlesource.com/#/c/431259/
It is none of f2fs business. :) :)
Thanks.

> 
> Thanks.
> 
> -----éäåä-----
> åää: Chao Yu [mailto:chao@xxxxxxxxxx]
> åéæé: 2017å7æ7æ 8:58
> æää: Jaegeuk Kim
> æé: linux-fsdevel@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; 
> linux-f2fs-devel@xxxxxxxxxxxxxxxxxxxxx
> äé: Re: [f2fs-dev] [PATCH] f2fs: relax permission for atomic/volatile 
> ioctls
> 
> On 2017/7/7 8:16, Jaegeuk Kim wrote:
> > On 07/07, Chao Yu wrote:
> >> On 2017/7/6 10:23, Jaegeuk Kim wrote:
> >>> This patch allows atomic/volatile ioctls for sqlite under sdcardfs.
> >>
> >> Out of curiosity, we will lose some capable when passing through sdcardfs?
> > 
> > I don't think so. But, it seems a test applicaion tries to access 
> > database from difference uid.
> 
> Oh, is that really allowed? if the sqlite database is public in sdcard 
> directory, application needs to apply WRITE_EXTERNAL_STORAGE in order 
> to add itself to sdcard_rw group, then it can access the database. Right?
> 
> Thanks,
> 
> > 
> > Thanks,
> > 
> >>
> >> Thanks,
> >>
> >>>
> >>> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx>> ---  
> >>> fs/f2fs/file.c | 15 ---------------
> >>>  1 file changed, 15 deletions(-)
> >>>
> >>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 
> >>> f5d6357e8360..dd8f5d2caa48 100644
> >>> --- a/fs/f2fs/file.c
> >>> +++ b/fs/f2fs/file.c
> >>> @@ -1587,9 +1587,6 @@ static int f2fs_ioc_start_atomic_write(struct file *filp)
> >>>  	struct inode *inode = file_inode(filp);
> >>>  	int ret;
> >>>  
> >>> -	if (!inode_owner_or_capable(inode))
> >>> -		return -EACCES;
> >>> -
> >>>  	if (!S_ISREG(inode->i_mode))
> >>>  		return -EINVAL;
> >>>  
> >>> @@ -1636,9 +1633,6 @@ static int f2fs_ioc_commit_atomic_write(struct file *filp)
> >>>  	struct inode *inode = file_inode(filp);
> >>>  	int ret;
> >>>  
> >>> -	if (!inode_owner_or_capable(inode))
> >>> -		return -EACCES;
> >>> -
> >>>  	ret = mnt_want_write_file(filp);
> >>>  	if (ret)
> >>>  		return ret;
> >>> @@ -1672,9 +1666,6 @@ static int f2fs_ioc_start_volatile_write(struct file *filp)
> >>>  	struct inode *inode = file_inode(filp);
> >>>  	int ret;
> >>>  
> >>> -	if (!inode_owner_or_capable(inode))
> >>> -		return -EACCES;
> >>> -
> >>>  	if (!S_ISREG(inode->i_mode))
> >>>  		return -EINVAL;
> >>>  
> >>> @@ -1707,9 +1698,6 @@ static int f2fs_ioc_release_volatile_write(struct file *filp)
> >>>  	struct inode *inode = file_inode(filp);
> >>>  	int ret;
> >>>  
> >>> -	if (!inode_owner_or_capable(inode))
> >>> -		return -EACCES;
> >>> -
> >>>  	ret = mnt_want_write_file(filp);
> >>>  	if (ret)
> >>>  		return ret;
> >>> @@ -1736,9 +1724,6 @@ static int f2fs_ioc_abort_volatile_write(struct file *filp)
> >>>  	struct inode *inode = file_inode(filp);
> >>>  	int ret;
> >>>  
> >>> -	if (!inode_owner_or_capable(inode))
> >>> -		return -EACCES;
> >>> -
> >>>  	ret = mnt_want_write_file(filp);
> >>>  	if (ret)
> >>>  		return ret;
> >>>
> 
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