diff options
| author | Gao Xiang <gaoxiang25@huawei.com> | 2018-12-08 00:19:12 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-12-07 17:10:48 +0100 |
| commit | 848bd9acdcd00c164b42b14aacec242949ecd471 (patch) | |
| tree | d8de2f0e2b6321620afd14e75f452227f4f93223 /drivers/staging/erofs | |
| parent | 7eb2a0438262ece07e57a371de0c88dc50bf8556 (diff) | |
staging: erofs: fix use-after-free of on-stack `z_erofs_vle_unzip_io'
The root cause is the race as follows:
Thread #0 Thread #1
z_erofs_vle_unzip_kickoff z_erofs_submit_and_unzip
struct z_erofs_vle_unzip_io io[]
atomic_add_return()
wait_event()
[end of function]
wake_up()
Fix it by taking the waitqueue lock between atomic_add_return and
wake_up to close such the race.
kernel message:
Unable to handle kernel paging request at virtual address 97f7052caa1303dc
...
Workqueue: kverityd verity_work
task: ffffffe32bcb8000 task.stack: ffffffe3298a0000
PC is at __wake_up_common+0x48/0xa8
LR is at __wake_up+0x3c/0x58
...
Call trace:
...
[<ffffff94a08ff648>] __wake_up_common+0x48/0xa8
[<ffffff94a08ff8b8>] __wake_up+0x3c/0x58
[<ffffff94a0c11b60>] z_erofs_vle_unzip_kickoff+0x40/0x64
[<ffffff94a0c118e4>] z_erofs_vle_read_endio+0x94/0x134
[<ffffff94a0c83c9c>] bio_endio+0xe4/0xf8
[<ffffff94a1076540>] dec_pending+0x134/0x32c
[<ffffff94a1076f28>] clone_endio+0x90/0xf4
[<ffffff94a0c83c9c>] bio_endio+0xe4/0xf8
[<ffffff94a1095024>] verity_work+0x210/0x368
[<ffffff94a08c4150>] process_one_work+0x188/0x4b4
[<ffffff94a08c45bc>] worker_thread+0x140/0x458
[<ffffff94a08cad48>] kthread+0xec/0x108
[<ffffff94a0883ab4>] ret_from_fork+0x10/0x1c
Code: d1006273 54000260 f9400804 b9400019 (b85fc081)
---[ end trace be9dde154f677cd1 ]---
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/staging/erofs')
| -rw-r--r-- | drivers/staging/erofs/unzip_vle.c | 13 |
1 files changed, 9 insertions, 4 deletions
diff --git a/drivers/staging/erofs/unzip_vle.c b/drivers/staging/erofs/unzip_vle.c index f5d088fdf7f2..4404ea6fb9e4 100644 --- a/drivers/staging/erofs/unzip_vle.c +++ b/drivers/staging/erofs/unzip_vle.c @@ -744,13 +744,18 @@ static void z_erofs_vle_unzip_kickoff(void *ptr, int bios) struct z_erofs_vle_unzip_io *io = tagptr_unfold_ptr(t); bool background = tagptr_unfold_tags(t); - if (atomic_add_return(bios, &io->pending_bios)) + if (!background) { + unsigned long flags; + + spin_lock_irqsave(&io->u.wait.lock, flags); + if (!atomic_add_return(bios, &io->pending_bios)) + wake_up_locked(&io->u.wait); + spin_unlock_irqrestore(&io->u.wait.lock, flags); return; + } - if (background) + if (!atomic_add_return(bios, &io->pending_bios)) queue_work(z_erofs_workqueue, &io->u.work); - else - wake_up(&io->u.wait); } static inline void z_erofs_vle_read_endio(struct bio *bio) |