On 2022/8/3 16:53, Jaewook Kim wrote:
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") Signed-off-by: Junbeom Yeom <[email protected]> Signed-off-by: Sungjong Seo <[email protected]> Signed-off-by: Youngjin Gil <[email protected]> Signed-off-by: Jaewook Kim <[email protected]>
Reviewed-by: Chao Yu <[email protected]> Thanks, _______________________________________________ Linux-f2fs-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel
