Searched hist:"40 a673b4" (Results 1 – 1 of 1) sorted by relevance
/openbmc/linux/fs/quota/ |
H A D | dquot.c | 40a673b4 Fri Feb 02 02:18:52 CST 2024 Wang Jianjian <wangjianjian3@huawei.com> quota: Fix potential NULL pointer dereference
[ Upstream commit d0aa72604fbd80c8aabb46eda00535ed35570f1f ]
Below race may cause NULL pointer dereference
P1 P2 dquot_free_inode quota_off drop_dquot_ref remove_dquot_ref dquots = i_dquot(inode) dquots = i_dquot(inode) srcu_read_lock dquots[cnt]) != NULL (1) dquots[type] = NULL (2) spin_lock(&dquots[cnt]->dq_dqb_lock) (3) ....
If dquot_free_inode(or other routines) checks inode's quota pointers (1) before quota_off sets it to NULL(2) and use it (3) after that, NULL pointer dereference will be triggered.
So let's fix it by using a temporary pointer to avoid this issue.
Signed-off-by: Wang Jianjian <wangjianjian3@huawei.com> Signed-off-by: Jan Kara <jack@suse.cz> Message-Id: <20240202081852.2514092-1-wangjianjian3@huawei.com> Stable-dep-of: 179b8c97ebf6 ("quota: Fix rcu annotations of inode dquot pointers") Signed-off-by: Sasha Levin <sashal@kernel.org>
|