Messages in this thread | | | From | "Sungjong Seo" <> | Subject | RE: [PATCH] f2fs: do not allow to decompress files have FI_COMPRESS_RELEASED | Date | Wed, 3 Aug 2022 12:45:48 +0900 |
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> If a file has FI_COMPRESS_RELEASED, all writes for it should not be > allowed. However, as of now, in case of compress_mode=user, writes > triggered by IOCTLs like F2FS_IOC_DE/COMPRESS_FILE are allowed unexpectly, > which could crash that file. > To fix it, let's do not allow F2FS_IOC_DE/COMPRESS_IOCTL if a file already > has FI_COMPRESS_RELEASED flag. > > This is the reproduction process: > 1. $ chattr +c ./file > 2. $ dd if=/dev/zero of=./file bs=4096 count=2000 oflag=append > conv=notrunc 3. $ sync > 4. $ do_compress ./file ; call F2FS_IOC_COMPRESS_FILE > 5. $ get_compr_blocks ./file ; call F2FS_IOC_GET_COMPRESS_BLOCKS
Oops! Do we need to call F2FS_IOC_RELEASE_COMPRESS_BLOCKS here? Maybe, you need to revise reproduction process and to make v2 patch.
> 6. $ do_compress ./file ; call F2FS_IOC_COMPRESS_FILE again > 7. $ get_compr_blocks ./file ; call F2FS_IOC_GET_COMPRESS_BLOCKS again > > You can find compr_blocks has a negative value. > > Fixes: 5fdb322ff2c2b ("f2fs: add F2FS_IOC_DECOMPRESS_FILE and > F2FS_IOC_COMPRESS_FILE") > > Signed-off-by: Junbeom Yeom <junbeom.yeom@samsung.com> > Signed-off-by: Sungjong Seo <sj1557.seo@samsung.com> > Signed-off-by: Youngjin Gil <youngjin.gil@samsung.com> > Signed-off-by: Jaewook Kim <jw5454.kim@samsung.com> > --- > fs/f2fs/file.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index > 6b1b030830ca..a4713b7e12cb 100644 > --- a/fs/f2fs/file.c > +++ b/fs/f2fs/file.c > @@ -3945,6 +3945,11 @@ static int f2fs_ioc_decompress_file(struct file > *filp, unsigned long arg) > goto out; > } > > + if (is_inode_flag_set(inode, FI_COMPRESS_RELEASED)) { > + ret = -EINVAL; > + goto out; > + } > + > ret = filemap_write_and_wait_range(inode->i_mapping, 0, LLONG_MAX); > if (ret) > goto out; > @@ -4012,6 +4017,11 @@ static int f2fs_ioc_compress_file(struct file *filp, > unsigned long arg) > goto out; > } > > + if (is_inode_flag_set(inode, FI_COMPRESS_RELEASED)) { > + ret = -EINVAL; > + goto out; > + } > + > ret = filemap_write_and_wait_range(inode->i_mapping, 0, LLONG_MAX); > if (ret) > goto out; > -- > 2.17.1
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