BACKPORT: f2fs: do not allow to decompress files have FI_COMPRESS_RELEASED

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.  $ touch ./file
2.  $ chattr +c ./file
3.  $ dd if=/dev/random of=./file bs=4096 count=30 conv=notrunc
4.  $ dd if=/dev/zero of=./file bs=4096 count=34 seek=30 conv=notrunc
5.  $ sync
6.  $ do_compress ./file      ; call F2FS_IOC_COMPRESS_FILE
7.  $ get_compr_blocks ./file ; call F2FS_IOC_GET_COMPRESS_BLOCKS
8.  $ release ./file          ; call F2FS_IOC_RELEASE_COMPRESS_BLOCKS
9.  $ do_compress ./file      ; call F2FS_IOC_COMPRESS_FILE again
10. $ get_compr_blocks ./file ; call F2FS_IOC_GET_COMPRESS_BLOCKS again

This reproduction process is tested in 128kb cluster size.
You can find compr_blocks has a negative value.

Fixes: 5fdb322ff2c2b ("f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE")

Bug: 228919347
Bug: 267580491
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>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
(cherry picked from commit 854f8871ed48229d217edd7cb023f749e4a0817b)
Change-Id: I086e4d88da68574ef793740d19ecbb2d4ad6ef1d
This commit is contained in:
Jaewook Kim
2022-08-03 17:53:58 +09:00
committed by Treehugger Robot
parent 16996773d6
commit a20fd832a4

View File

@@ -4121,6 +4121,11 @@ 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;
@@ -4188,6 +4193,11 @@ 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;