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| author | Theodore Ts'o <tytso@mit.edu> | 2021-01-21 12:33:20 -0500 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2021-02-02 23:16:01 -0500 |
| commit | 027f14f5357279655c3ebc6d14daff8368d4f53f (patch) | |
| tree | c09d01267b542969dd3a72b93cfe4b6f1b069671 /fs/ext4/super.c | |
| parent | 59ebc7fd74506367b109497eeef36034e648c943 (diff) | |
| download | linux-027f14f5357279655c3ebc6d14daff8368d4f53f.tar.gz | |
ext4: don't try to processed freed blocks until mballoc is initialized
If we try to make any changes via the journal between when the journal
is initialized, but before the multi-block allocated is initialized,
we will end up deferencing a NULL pointer when the journal commit
callback function calls ext4_process_freed_data().
The proximate cause of this failure was commit 2d01ddc86606 ("ext4:
save error info to sb through journal if available") since file system
corruption problems detected before the call to ext4_mb_init() would
result in a journal commit before we aborted the mount of the file
system.... and we would then trigger the NULL pointer deref.
Link: https://lore.kernel.org/r/YAm8qH/0oo2ofSMR@mit.edu
Reported-by: Murphy Zhou <jencce.kernel@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/super.c')
| -rw-r--r-- | fs/ext4/super.c | 9 |
1 files changed, 8 insertions, 1 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index f361f9fb40d1..071d131fadd8 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -4875,7 +4875,6 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) set_task_ioprio(sbi->s_journal->j_task, journal_ioprio); - sbi->s_journal->j_commit_callback = ext4_journal_commit_callback; sbi->s_journal->j_submit_inode_data_buffers = ext4_journal_submit_inode_data_buffers; sbi->s_journal->j_finish_inode_data_buffers = @@ -4987,6 +4986,14 @@ no_journal: goto failed_mount5; } + /* + * We can only set up the journal commit callback once + * mballoc is initialized + */ + if (sbi->s_journal) + sbi->s_journal->j_commit_callback = + ext4_journal_commit_callback; + block = ext4_count_free_clusters(sb); ext4_free_blocks_count_set(sbi->s_es, EXT4_C2B(sbi, block)); |