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bcachefs: Fix null-ptr-deref in bch2_fs_alloc()

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There is a null-ptr-deref issue reported by kasan:

  KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
  Call Trace:
    <TASK>
    bch2_fs_alloc+0x1092/0x2170 [bcachefs]
    bch2_fs_open+0x683/0xe10 [bcachefs]
    ...

When initializing the name of bch_fs, it needs to dynamically alloc memory
to meet the length of the name. However, when name allocation failed, it
will cause a null-ptr-deref access exception in subsequent string copy.

Fix this issue by checking if name allocation is successful.

Fixes: 401ec4db63 ("bcachefs: Printbuf rework")
Signed-off-by: Li Zetao <lizetao1@huawei.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
This commit is contained in:
Li Zetao 2024-03-04 11:22:03 +08:00 committed by Kent Overstreet
parent d206a76d7d
commit f8cdf65b51
1 changed files with 3 additions and 3 deletions
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6
fs/bcachefs/super.c
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@ -818,13 +818,13 @@ static struct bch_fs *bch2_fs_alloc(struct bch_sb *sb, struct bch_opts opts)
goto err;
pr_uuid(&name, c->sb.user_uuid.b);
strscpy(c->name, name.buf, sizeof(c->name));
printbuf_exit(&name);
ret = name.allocation_failure ? -BCH_ERR_ENOMEM_fs_name_alloc : 0;
if (ret)
goto err;
strscpy(c->name, name.buf, sizeof(c->name));
printbuf_exit(&name);
/* Compat: */
if (le16_to_cpu(sb->version) <= bcachefs_metadata_version_inode_v2 &&
!BCH_SB_JOURNAL_FLUSH_DELAY(sb))