diff options
| author | Dongliang Mu <mudongliangabcd@gmail.com> | 2021-11-04 16:22:01 +0800 |
|---|---|---|
| committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2021-11-09 08:23:17 -0800 |
| commit | 5429c9dbc9025f9a166f64e22e3a69c94fd5b29b (patch) | |
| tree | 2197c2964b98c5eea5f6d05d72c378fb6bd1b508 /fs/f2fs | |
| parent | e3b49ea36802053f312013fd4ccb6e59920a9f76 (diff) | |
f2fs: fix UAF in f2fs_available_free_memory
if2fs_fill_super
-> f2fs_build_segment_manager
-> create_discard_cmd_control
-> f2fs_start_discard_thread
It invokes kthread_run to create a thread and run issue_discard_thread.
However, if f2fs_build_node_manager fails, the control flow goes to
free_nm and calls f2fs_destroy_node_manager. This function will free
sbi->nm_info. However, if issue_discard_thread accesses sbi->nm_info
after the deallocation, but before the f2fs_stop_discard_thread, it will
cause UAF(Use-after-free).
-> f2fs_destroy_segment_manager
-> destroy_discard_cmd_control
-> f2fs_stop_discard_thread
Fix this by stopping discard thread before f2fs_destroy_node_manager.
Note that, the commit d6d2b491a82e1 introduces the call of
f2fs_available_free_memory into issue_discard_thread.
Cc: stable@vger.kernel.org
Fixes: d6d2b491a82e ("f2fs: allow to change discard policy based on cached discard cmds")
Signed-off-by: Dongliang Mu <mudongliangabcd@gmail.com>
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Diffstat (limited to 'fs/f2fs')
| -rw-r--r-- | fs/f2fs/super.c | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index 75f706b91ebf..60cb2ede4fdd 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -4385,6 +4385,8 @@ free_node_inode: free_stats: f2fs_destroy_stats(sbi); free_nm: + /* stop discard thread before destroying node manager */ + f2fs_stop_discard_thread(sbi); f2fs_destroy_node_manager(sbi); free_sm: f2fs_destroy_segment_manager(sbi); |