Re: [PATCH] squashfs: Avoid mem leak in squashfs_fill_super

[Scott Guo]

在 2025/8/12 6:35, Phillip Lougher 写道:
> On 11/08/2025 07:19, scott_gzh@xxxxxxx wrote:
> > From: Scott GUO <scottzhguo@xxxxxxxxxxx>
> >
> > If sb_min_blocksize returns 0, -EINVAL was returned without freeing
> > sb->s_fs_info, causing mem leak.
> >
> > Fix it by goto failed_mount.
>
> Thanks for spotting this, but, NACK to the patch.
>
> A better fix is to call sb_min_blocksize and check the
> return result before the memory is allocated.
OK, will send v2.>
> Phillip
>
> > Fixes: 734aa85390ea ("Squashfs: check return result of sb_min_blocksize")
> > Signed-off-by: Scott GUO <scottzhguo@xxxxxxxxxxx>
> > ---
> >   fs/squashfs/super.c | 6 +++---
> >   1 file changed, 3 insertions(+), 3 deletions(-)
> >
> > diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c
> > index 992ea0e37257..7d501083b2e3 100644
> > --- a/fs/squashfs/super.c
> > +++ b/fs/squashfs/super.c
> > @@ -201,10 +201,12 @@ static int squashfs_fill_super(struct 
> > super_block *sb, struct fs_context *fc)
> >       msblk->panic_on_errors = (opts->errors == Opt_errors_panic);
> > +    err = -EINVAL;
> > +
> >       msblk->devblksize = sb_min_blocksize(sb, SQUASHFS_DEVBLK_SIZE);
> >       if (!msblk->devblksize) {
> >           errorf(fc, "squashfs: unable to set blocksize\n");
> > -        return -EINVAL;
> > +        goto failed_mount;
> >       }
> >       msblk->devblksize_log2 = ffz(~msblk->devblksize);
> > @@ -227,8 +229,6 @@ static int squashfs_fill_super(struct super_block 
> > *sb, struct fs_context *fc)
> >           goto failed_mount;
> >       }
> > -    err = -EINVAL;
> > -
> >       /* Check it is a SQUASHFS superblock */
> >       sb->s_magic = le32_to_cpu(sblk->s_magic);
> >       if (sb->s_magic != SQUASHFS_MAGIC) {