[PATCH 1/8] aio: make sure file is pinned
From: Al Viro <viro@ZenIV.linux.org.uk>
Date: 2019-03-07 00:04:34
Also in:
linux-fsdevel, lkml
Subsystem:
aio, filesystems (vfs and infrastructure), the rest · Maintainers:
Benjamin LaHaise, Alexander Viro, Christian Brauner, Linus Torvalds
From: Al Viro <viro@zeniv.linux.org.uk> "aio: remove the extra get_file/fput pair in io_submit_one" was too optimistic - not dereferencing file pointer after e.g. ->write_iter() returns is not enough; that reference might've been the only thing that kept alive objects that are referenced *before* the method returns. Such as inode, for example... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> --- fs/aio.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/fs/aio.c b/fs/aio.c
index 3d9669d011b9..ea30b78187ed 100644
--- a/fs/aio.c
+++ b/fs/aio.c@@ -1790,6 +1790,7 @@ static int __io_submit_one(struct kioctx *ctx, const struct iocb *iocb, struct iocb __user *user_iocb, bool compat) { struct aio_kiocb *req; + struct file *file; ssize_t ret; /* enforce forwards compatibility on users */
@@ -1844,6 +1845,7 @@ static int __io_submit_one(struct kioctx *ctx, const struct iocb *iocb, req->ki_user_iocb = user_iocb; req->ki_user_data = iocb->aio_data; + file = get_file(req->ki_filp); /* req can die too early */ switch (iocb->aio_lio_opcode) { case IOCB_CMD_PREAD:
@@ -1872,6 +1874,7 @@ static int __io_submit_one(struct kioctx *ctx, const struct iocb *iocb, ret = -EINVAL; break; } + fput(file); /* * If ret is 0, we'd either done aio_complete() ourselves or have
--
2.11.0