Currently flags passed via Q_SETINFO were just stored. This makes it hard to add new flags since in theory userspace could be just setting / clearing random flags. Since currently there is only one userspace settable flag and that is somewhat obscure flags only for ancient v1 quota format, I'm reasonably sure noone operates these flags and hopefully we are fine just adding the check that passed flags are sane. If we indeed find some userspace program that gets broken by the strict check, we can always remove it again. Signed-off-by: Jan Kara <jack@xxxxxxx> --- fs/quota/dquot.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index a6b5795a4181..02d571cb010a 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -2649,6 +2649,14 @@ int dquot_set_dqinfo(struct super_block *sb, int type, struct if_dqinfo *ii) goto out; } mi = sb_dqopt(sb)->info + type; + if (ii->dqi_valid & IIF_FLAGS) { + if (ii->dqi_flags & ~DQF_SETINFO_MASK || + (ii->dqi_flags & DQF_ROOT_SQUASH && + mi->dqi_format->qf_fmt_id != QFMT_VFS_OLD)) { + err = -EINVAL; + goto out; + } + } spin_lock(&dq_data_lock); if (ii->dqi_valid & IIF_BGRACE) mi->dqi_bgrace = ii->dqi_bgrace; -- 1.8.4.5 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html