[PATCH 5.16 0111/1017] ocfs2: fix crash when mount with quota enabled

Greg Kroah-Hartman
2022-04-05T09:27:52Z

From: Joseph Qi <joseph.qi@linux.alibaba.com>

commit de19433423c7bedabbd4f9a25f7dbc62c5e78921 upstream.

There is a reported crash when mounting ocfs2 with quota enabled.

RIP: 0010:ocfs2_qinfo_lock_res_init+0x44/0x50 [ocfs2]
Call Trace:
ocfs2_local_read_info+0xb9/0x6f0 [ocfs2]
dquot_load_quota_sb+0x216/0x470
dquot_load_quota_inode+0x85/0x100
ocfs2_enable_quotas+0xa0/0x1c0 [ocfs2]
ocfs2_fill_super.cold+0xc8/0x1bf [ocfs2]
mount_bdev+0x185/0x1b0
legacy_get_tree+0x27/0x40
vfs_get_tree+0x25/0xb0
path_mount+0x465/0xac0
__x64_sys_mount+0x103/0x140

It is caused by when initializing dqi_gqlock, the corresponding dqi_type
and dqi_sb are not properly initialized.

This issue is introduced by commit 6c85c2c72819, which wants to avoid
accessing uninitialized variables in error cases. So make global quota
info properly initialized.

Link: https://lkml.kernel.org/r/20220323023644.40084-1-joseph.qi@linux.alibaba.com
Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1007141
Fixes: 6c85c2c72819 ("ocfs2: quota_local: fix possible uninitialized-variable access in ocfs2_local_read_info()")
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reported-by: Dayvison <sathlerds@gmail.com>
Tested-by: Valentin Vidic <vvidic@valentin-vidic.from.hr>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/ocfs2/quota_global.c | 23 ++++++++++++-----------
fs/ocfs2/quota_local.c | 2 --
2 files changed, 12 insertions(+), 13 deletions(-)

--- a/fs/ocfs2/quota_global.c
+++ b/fs/ocfs2/quota_global.c
@@ -337,7 +337,6 @@ void ocfs2_unlock_global_qf(struct ocfs2
/* Read information header from global quota file */
int ocfs2_global_read_info(struct super_block *sb, int type)
{
- struct inode *gqinode = NULL;
unsigned int ino[OCFS2_MAXQUOTAS] = { USER_QUOTA_SYSTEM_INODE,
GROUP_QUOTA_SYSTEM_INODE };
struct ocfs2_global_disk_dqinfo dinfo;
@@ -346,29 +345,31 @@ int ocfs2_global_read_info(struct super_
u64 pcount;
int status;

+ oinfo->dqi_gi.dqi_sb = sb;
+ oinfo->dqi_gi.dqi_type = type;
+ ocfs2_qinfo_lock_res_init(&oinfo->dqi_gqlock, oinfo);
+ oinfo->dqi_gi.dqi_entry_size = sizeof(struct ocfs2_global_disk_dqblk);
+ oinfo->dqi_gi.dqi_ops = &ocfs2_global_ops;
+ oinfo->dqi_gqi_bh = NULL;
+ oinfo->dqi_gqi_count = 0;
+
/* Read global header */
- gqinode = ocfs2_get_system_file_inode(OCFS2_SB(sb), ino[type],
+ oinfo->dqi_gqinode = ocfs2_get_system_file_inode(OCFS2_SB(sb), ino[type],
OCFS2_INVALID_SLOT);
- if (!gqinode) {
+ if (!oinfo->dqi_gqinode) {
mlog(ML_ERROR, "failed to get global quota inode (type=%d)\n",
type);
status = -EINVAL;
goto out_err;
}
- oinfo->dqi_gi.dqi_sb = sb;
- oinfo->dqi_gi.dqi_type = type;
- oinfo->dqi_gi.dqi_entry_size = sizeof(struct ocfs2_global_disk_dqblk);
- oinfo->dqi_gi.dqi_ops = &ocfs2_global_ops;
- oinfo->dqi_gqi_bh = NULL;
- oinfo->dqi_gqi_count = 0;
- oinfo->dqi_gqinode = gqinode;
+
status = ocfs2_lock_global_qf(oinfo, 0);
if (status < 0) {
mlog_errno(status);
goto out_err;
}

- status = ocfs2_extent_map_get_blocks(gqinode, 0, &oinfo->dqi_giblk,
+ status = ocfs2_extent_map_get_blocks(oinfo->dqi_gqinode, 0, &oinfo->dqi_giblk,
&pcount, NULL);
if (status < 0)
goto out_unlock;
--- a/fs/ocfs2/quota_local.c
+++ b/fs/ocfs2/quota_local.c
@@ -702,8 +702,6 @@ static int ocfs2_local_read_info(struct
info->dqi_priv = oinfo;
oinfo->dqi_type = type;
INIT_LIST_HEAD(&oinfo->dqi_chunk);
- oinfo->dqi_gqinode = NULL;
- ocfs2_qinfo_lock_res_init(&oinfo->dqi_gqlock, oinfo);
oinfo->dqi_rec = NULL;
oinfo->dqi_lqi_bh = NULL;
oinfo->dqi_libh = NULL;