diff options
| author | Dmitry Antipov <dmantipov@yandex.ru> | 2024-10-29 12:17:36 +0300 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2024-11-11 17:17:04 -0800 |
| commit | adc77b19f62d7e80f98400b2fca9d700d2afdd6f (patch) | |
| tree | 987baf1291bef8d9deefe24a7f6f52fa4820b0a4 | |
| parent | 62bf7065cc6056a51a240c810b95d887e5bb7c8c (diff) | |
ocfs2: fix uninitialized value in ocfs2_file_read_iter()
Syzbot has reported the following KMSAN splat:
BUG: KMSAN: uninit-value in ocfs2_file_read_iter+0x9a4/0xf80
ocfs2_file_read_iter+0x9a4/0xf80
__io_read+0x8d4/0x20f0
io_read+0x3e/0xf0
io_issue_sqe+0x42b/0x22c0
io_wq_submit_work+0xaf9/0xdc0
io_worker_handle_work+0xd13/0x2110
io_wq_worker+0x447/0x1410
ret_from_fork+0x6f/0x90
ret_from_fork_asm+0x1a/0x30
Uninit was created at:
__alloc_pages_noprof+0x9a7/0xe00
alloc_pages_mpol_noprof+0x299/0x990
alloc_pages_noprof+0x1bf/0x1e0
allocate_slab+0x33a/0x1250
___slab_alloc+0x12ef/0x35e0
kmem_cache_alloc_bulk_noprof+0x486/0x1330
__io_alloc_req_refill+0x84/0x560
io_submit_sqes+0x172f/0x2f30
__se_sys_io_uring_enter+0x406/0x41c0
__x64_sys_io_uring_enter+0x11f/0x1a0
x64_sys_call+0x2b54/0x3ba0
do_syscall_64+0xcd/0x1e0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Since an instance of 'struct kiocb' may be passed from the block layer
with 'private' field uninitialized, introduce 'ocfs2_iocb_init_rw_locked()'
and use it from where 'ocfs2_dio_end_io()' might take care, i.e. in
'ocfs2_file_read_iter()' and 'ocfs2_file_write_iter()'.
Link: https://lkml.kernel.org/r/20241029091736.1501946-1-dmantipov@yandex.ru
Fixes: 7cdfc3a1c397 ("ocfs2: Remember rw lock level during direct io")
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Reported-by: syzbot+a73e253cca4f0230a5a5@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=a73e253cca4f0230a5a5
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| -rw-r--r-- | fs/ocfs2/aops.h | 2 | ||||
| -rw-r--r-- | fs/ocfs2/file.c | 4 |
2 files changed, 6 insertions, 0 deletions
diff --git a/fs/ocfs2/aops.h b/fs/ocfs2/aops.h index 45db1781ea73..1d1b4b7edba0 100644 --- a/fs/ocfs2/aops.h +++ b/fs/ocfs2/aops.h @@ -70,6 +70,8 @@ enum ocfs2_iocb_lock_bits { OCFS2_IOCB_NUM_LOCKS }; +#define ocfs2_iocb_init_rw_locked(iocb) \ + (iocb->private = NULL) #define ocfs2_iocb_clear_rw_locked(iocb) \ clear_bit(OCFS2_IOCB_RW_LOCK, (unsigned long *)&iocb->private) #define ocfs2_iocb_rw_locked_level(iocb) \ diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index 06af21982c16..cb09330a0861 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -2398,6 +2398,8 @@ static ssize_t ocfs2_file_write_iter(struct kiocb *iocb, } else inode_lock(inode); + ocfs2_iocb_init_rw_locked(iocb); + /* * Concurrent O_DIRECT writes are allowed with * mount_option "coherency=buffered". @@ -2544,6 +2546,8 @@ static ssize_t ocfs2_file_read_iter(struct kiocb *iocb, if (!direct_io && nowait) return -EOPNOTSUPP; + ocfs2_iocb_init_rw_locked(iocb); + /* * buffered reads protect themselves in ->read_folio(). O_DIRECT reads * need locks to protect pending reads from racing with truncate. |