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author | Dongliang Mu <mudongliangabcd@gmail.com> | 2021-11-04 16:22:01 +0800 |
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committer | Jaegeuk Kim <jaegeuk@kernel.org> | 2021-11-09 08:23:17 -0800 |
commit | 5429c9dbc9025f9a166f64e22e3a69c94fd5b29b (patch) | |
tree | 2197c2964b98c5eea5f6d05d72c378fb6bd1b508 /fs/erofs/zdata.h | |
parent | e3b49ea36802053f312013fd4ccb6e59920a9f76 (diff) | |
download | linux-stable-5429c9dbc9025f9a166f64e22e3a69c94fd5b29b.tar.gz linux-stable-5429c9dbc9025f9a166f64e22e3a69c94fd5b29b.tar.bz2 linux-stable-5429c9dbc9025f9a166f64e22e3a69c94fd5b29b.zip |
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/erofs/zdata.h')
0 files changed, 0 insertions, 0 deletions