This is a note to let you know that I've just added the patch titled
io_uring: statx must grab the file table for valid fd
to the 5.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
io_uring-statx-must-grab-the-file-table-for-valid-fd.patch
and it can be found in the queue-5.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From 5b0bbee4732cbd58aa98213d4c11a366356bba3d Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@xxxxxxxxx>
Date: Mon, 27 Apr 2020 10:41:22 -0600
Subject: io_uring: statx must grab the file table for valid fd
From: Jens Axboe <axboe@xxxxxxxxx>
commit 5b0bbee4732cbd58aa98213d4c11a366356bba3d upstream.
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@xxxxxxxxxxxxxxx # v5.6
Reported-by: Clay Harris <bugs@xxxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/io_uring.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -479,6 +479,7 @@ enum {
REQ_F_COMP_LOCKED_BIT,
REQ_F_NEED_CLEANUP_BIT,
REQ_F_OVERFLOW_BIT,
+ REQ_F_NO_FILE_TABLE_BIT,
};
enum {
@@ -521,6 +522,8 @@ enum {
REQ_F_NEED_CLEANUP = BIT(REQ_F_NEED_CLEANUP_BIT),
/* in overflow list */
REQ_F_OVERFLOW = BIT(REQ_F_OVERFLOW_BIT),
+ /* doesn't need file table for this request */
+ REQ_F_NO_FILE_TABLE = BIT(REQ_F_NO_FILE_TABLE_BIT),
};
/*
@@ -711,6 +714,7 @@ 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,
@@ -2843,8 +2847,12 @@ static int io_statx(struct io_kiocb *req
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;
@@ -4632,7 +4640,7 @@ static int io_grab_files(struct io_kiocb
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;
Patches currently in stable-queue which might be from axboe@xxxxxxxxx are
queue-5.6/io_uring-statx-must-grab-the-file-table-for-valid-fd.patch
queue-5.6/block-remove-the-bd_openers-checks-in-blk_drop_partitions.patch
