friendly ping... On 2022/11/29 15:02, lihaoxiang (F) wrote: > In our knowledge, ext2fs_mmp_stop use to process the rest of work > when mmp will finish. Critically, it must check if the mmp block is > not changed. But there exist an error in comparing the mmp and mmp_cmp. > > Look to ext2fs_mmp_read, the assignment of mmp_cmp retrieve from the > superblock of disk and it copy to mmp_buf if mmp_buf is not none > and not equal to mmp_cmp in the meanwhile. However, ext2fs_mmp_stop > pass the no NULL pointer fs->mmp_buf which has possed the mmp info to > ext2fs_mmp_read. Consequently, ext2fs_mmp_read override fs->mmp_buf > by fs->mmp_cmp so that loss the meaning of comparing themselves > after that and worse yet, couldn't judge whether the struct of mmp > has changed. > > In fact, we only need to modify the parameter to NULL pointer for > solving this problem. > > Signed-off-by: lihaoxiang <lihaoxiang9@xxxxxxxxxx> > --- > lib/ext2fs/mmp.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/lib/ext2fs/mmp.c b/lib/ext2fs/mmp.c > index 7970aac2..14289706 100644 > --- a/lib/ext2fs/mmp.c > +++ b/lib/ext2fs/mmp.c > @@ -407,7 +407,7 @@ errcode_t ext2fs_mmp_stop(ext2_filsys fs) > (fs->mmp_buf == NULL) || (fs->mmp_cmp == NULL)) > goto mmp_error; > > - retval = ext2fs_mmp_read(fs, fs->super->s_mmp_block, fs->mmp_buf); > + retval = ext2fs_mmp_read(fs, fs->super->s_mmp_block, NULL); > if (retval) > goto mmp_error; >
