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From: Max Kellermann <mk@cm4all.com>
To: axboe@kernel.dk, linux-fsdevel@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, Max Kellermann <mk@cm4all.com>,
	stable@vger.kernel.org
Subject: [PATCH] fs/io_uring: fix O_PATH fds in openat, openat2, statx
Date: Thu,  7 May 2020 20:57:25 +0200	[thread overview]
Message-ID: <20200507185725.15840-1-mk@cm4all.com> (raw)

If an operation's flag `needs_file` is set, the function
io_req_set_file() calls io_file_get() to obtain a `struct file*`.

This fails for `O_PATH` file descriptors, because those have no
`struct file*`, causing io_req_set_file() to throw `-EBADF`.  This
breaks the operations `openat`, `openat2` and `statx`, where `O_PATH`
file descriptors are commonly used.

The solution is to simply remove `needs_file` (and the accompanying
flag `fd_non_reg`).  This flag was never needed because those
operations use numeric file descriptor and don't use the `struct
file*` obtained by io_req_set_file().

Signed-off-by: Max Kellermann <mk@cm4all.com>
Cc: stable@vger.kernel.org
---
 fs/io_uring.c | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index a46de2cfc28e..d24f8e33323c 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -693,8 +693,6 @@ static const struct io_op_def io_op_defs[] = {
 		.needs_file		= 1,
 	},
 	[IORING_OP_OPENAT] = {
-		.needs_file		= 1,
-		.fd_non_neg		= 1,
 		.file_table		= 1,
 		.needs_fs		= 1,
 	},
@@ -708,8 +706,6 @@ static const struct io_op_def io_op_defs[] = {
 	},
 	[IORING_OP_STATX] = {
 		.needs_mm		= 1,
-		.needs_file		= 1,
-		.fd_non_neg		= 1,
 		.needs_fs		= 1,
 	},
 	[IORING_OP_READ] = {
@@ -739,8 +735,6 @@ static const struct io_op_def io_op_defs[] = {
 		.unbound_nonreg_file	= 1,
 	},
 	[IORING_OP_OPENAT2] = {
-		.needs_file		= 1,
-		.fd_non_neg		= 1,
 		.file_table		= 1,
 		.needs_fs		= 1,
 	},
-- 
2.20.1


             reply	other threads:[~2020-05-07 18:57 UTC|newest]

Thread overview: 18+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-05-07 18:57 Max Kellermann [this message]
2020-05-07 18:58 ` [PATCH] fs/io_uring: fix O_PATH fds in openat, openat2, statx Jens Axboe
2020-05-07 19:01   ` Max Kellermann
2020-05-07 19:01 ` Al Viro
2020-05-07 19:05   ` Max Kellermann
2020-05-07 19:05   ` Jens Axboe
2020-05-07 19:12     ` Max Kellermann
2020-05-07 19:29     ` Al Viro
2020-05-07 19:37       ` Max Kellermann
2020-05-07 20:53       ` Jens Axboe
2020-05-07 22:06         ` Al Viro
2020-05-07 22:25           ` Jens Axboe
2020-05-07 22:44             ` Al Viro
2020-05-07 23:03               ` Jens Axboe
2020-05-07 23:31                 ` Al Viro
2020-05-08  2:28                   ` Jens Axboe
2020-05-08  2:53                     ` Jens Axboe
     [not found]                     ` <20200508152918.12340-1-hdanton@sina.com>
2020-05-08 15:33                       ` Jens Axboe

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