redonkable
/
alistair23-linux
1
0
Fork 0
Code Releases Activity

io_uring: statx must grab the file table for valid fd 

Clay reports that OP_STATX fails for a test case with a valid fd
and empty path:

 -- Test 0: statx:fd 3: SUCCEED, file mode 100755
 -- Test 1: statx:path ./uring_statx: SUCCEED, file mode 100755
 -- Test 2: io_uring_statx:fd 3: FAIL, errno 9: Bad file descriptor
 -- Test 3: io_uring_statx:path ./uring_statx: SUCCEED, file mode 100755

This is due to statx not grabbing the process file table, hence we can't
lookup the fd in async context. If the fd is valid, ensure that we grab
the file table so we can grab the file from async context.

Cc: stable@vger.kernel.org # v5.6
Reported-by: Clay Harris <bugs@claycon.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
alistair/sensors
Jens Axboe 2020-04-27 10:41:22 -06:00
parent 44575a6731
commit 5b0bbee473
1 changed files with 10 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

12
fs/io_uring.c
View File

@ -524,6 +524,7 @@ enum {
REQ_F_OVERFLOW_BIT,
REQ_F_POLLED_BIT,
REQ_F_BUFFER_SELECTED_BIT,
REQ_F_NO_FILE_TABLE_BIT,
/* not a real bit, just to check we're not overflowing the space */
__REQ_F_LAST_BIT,
@ -577,6 +578,8 @@ enum {
REQ_F_POLLED = BIT(REQ_F_POLLED_BIT),
/* buffer already selected */
REQ_F_BUFFER_SELECTED = BIT(REQ_F_BUFFER_SELECTED_BIT),
/* doesn't need file table for this request */
REQ_F_NO_FILE_TABLE = BIT(REQ_F_NO_FILE_TABLE_BIT),
};
struct async_poll {
@ -799,6 +802,7 @@ static const struct io_op_def io_op_defs[] = {
.needs_file = 1,
.fd_non_neg = 1,
.needs_fs = 1,
.file_table = 1,
},
[IORING_OP_READ] = {
.needs_mm = 1,
@ -3355,8 +3359,12 @@ static int io_statx(struct io_kiocb *req, bool force_nonblock)
struct kstat stat;
int ret;
if (force_nonblock)
if (force_nonblock) {
/* only need file table for an actual valid fd */
if (ctx->dfd == -1 || ctx->dfd == AT_FDCWD)
req->flags |= REQ_F_NO_FILE_TABLE;
return -EAGAIN;
}
if (vfs_stat_set_lookup_flags(&lookup_flags, ctx->how.flags))
return -EINVAL;
@ -5429,7 +5437,7 @@ static int io_grab_files(struct io_kiocb *req)
int ret = -EBADF;
struct io_ring_ctx *ctx = req->ctx;
if (req->work.files)
if (req->work.files || (req->flags & REQ_F_NO_FILE_TABLE))
return 0;
if (!ctx->ring_file)
return -EBADF;