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 io_file_get() calls
fget(), which rejects `O_PATH` file descriptors. To support `O_PATH`,
fdget_raw() must be used (like path_init() in `fs/namei.c` does).
This rejection causes io_req_set_file() to throw `-EBADF`. This
breaks the operations `openat`, `openat2` and `statx`, where `O_PATH`
file descriptors are commonly used.
This could be solved by adding support for `O_PATH` file descriptors
with another `io_op_def` flag, but since those three operations don't
need the `struct file*` but operate directly on the numeric file
descriptors, the best solution here is to simply remove `needs_file`
(and the accompanying flag `fd_non_reg`).
Signed-off-by: Max Kellermann <mk@xxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
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
