On 2024/1/26 16:57, Baokun Li wrote: > When setting values of type unsigned int through sysfs, we use kstrtoul() > to parse it and then truncate part of it as the final set value, when the > set value is greater than UINT_MAX, the set value will not match what we > see because of the truncation. As follows: > > $ echo 4294967296 > /sys/fs/ext4/sda/mb_max_linear_groups > $ cat /sys/fs/ext4/sda/mb_max_linear_groups > 0 > > So when the value set is outside the variable type range, -EINVAL is > returned to avoid the inconsistency described above. In addition, a > judgment is added to avoid setting s_resv_clusters less than 0. > > Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx> Thanks for the patch. Looks good to me. Reviewed-by: Zhang Yi <yi.zhang@xxxxxxxxxx> > --- > fs/ext4/sysfs.c | 4 +++- > 1 file changed, 3 insertions(+), 1 deletion(-) > > diff --git a/fs/ext4/sysfs.c b/fs/ext4/sysfs.c > index 6d332dff79dd..3671a8aaf4af 100644 > --- a/fs/ext4/sysfs.c > +++ b/fs/ext4/sysfs.c > @@ -104,7 +104,7 @@ static ssize_t reserved_clusters_store(struct ext4_sb_info *sbi, > int ret; > > ret = kstrtoull(skip_spaces(buf), 0, &val); > - if (ret || val >= clusters) > + if (ret || val >= clusters || (s64)val < 0) > return -EINVAL; > > atomic64_set(&sbi->s_resv_clusters, val); > @@ -463,6 +463,8 @@ static ssize_t ext4_attr_store(struct kobject *kobj, > ret = kstrtoul(skip_spaces(buf), 0, &t); > if (ret) > return ret; > + if (t != (unsigned int)t) > + return -EINVAL; > if (a->attr_ptr == ptr_ext4_super_block_offset) > *((__le32 *) ptr) = cpu_to_le32(t); > else >
