ocfs2: fix crash when mount with quota enabled

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>

diff --git a/fs/ocfs2/quota_global.c b/fs/ocfs2/quota_global.c
index 273f65e0aabac127be3d4175ee6b205b94a0aeef..0b6f551a342a176e8f3ad79aa1f11061a4946655 100644 (file)
--- a/fs/ocfs2/quota_global.c
+++ b/fs/ocfs2/quota_global.c
@@ -337,7 +337,6 @@ void ocfs2_unlock_global_qf(struct ocfs2_mem_dqinfo *oinfo, int ex)
 /* 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_block *sb, int type)
        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;

diff --git a/fs/ocfs2/quota_local.c b/fs/ocfs2/quota_local.c
index 0e4b16d4c037fae3f3eda96edcddf53800b55b21..b1a8b046f4c22a990af8c8bb26ecb709394dddf0 100644 (file)
--- a/fs/ocfs2/quota_local.c
+++ b/fs/ocfs2/quota_local.c
@@ -702,8 +702,6 @@ static int ocfs2_local_read_info(struct super_block *sb, int type)
        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;