From ca6cb0918e8765de304916a15554b42203e6e1fc Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 19 Nov 2014 09:32:39 +0100 Subject: quota: Verify flags passed to Q_SETINFO 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 --- fs/quota/dquot.c | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'fs/quota') diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c index f8be368b9086..d25c3243c196 100644 --- a/fs/quota/dquot.c +++ b/fs/quota/dquot.c @@ -2582,6 +2582,14 @@ 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; -- cgit v1.2.3-70-g09d2