Re: [PATCH 5.10/5.15] io_uring: fix registered files leak

Jens Axboe
2024-03-14T00:40:32Z

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Hi,

OK, here they are. Two patches attached for every stable kernel, that
gets rid of the remnants of the SCM related code:

5.4
5.10 and 5.15 (same patches)
6.1
6.6
6.7

Would appreciate if Fedor and Pavel could give them a once over, but I
think they are all fine. It's just deleting the code...

Barring no complaints, Greg can you queue them up? Thanks!

--
Jens Axboe

[-- Attachment #2: 5.4-0001-io_uring-unix-drop-usage-of-io_uring-socket.patch --]
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From 53e9e0ced4e4146ff57635c8ee65a57f3ed33fe3 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Wed, 13 Mar 2024 18:33:48 -0600
Subject: [PATCH 1/2] io_uring/unix: drop usage of io_uring socket

Commit a4104821ad651d8a0b374f0b2474c345bbb42f82 upstream.

Since we no longer allow sending io_uring fds over SCM_RIGHTS, move to
using io_is_uring_fops() to detect whether this is a io_uring fd or not.
With that done, kill off io_uring_get_socket() as nobody calls it
anymore.

This is in preparation to yanking out the rest of the core related to
unix gc with io_uring.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
fs/io_uring.c | 18 +++++-------------
include/linux/fs.h | 6 +++---
net/core/scm.c | 2 +-
net/unix/scm.c | 4 +---
4 files changed, 10 insertions(+), 20 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 9de8961763b0..cd1858cc6320 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -381,19 +381,6 @@ static struct kmem_cache *req_cachep;

static const struct file_operations io_uring_fops;

-struct sock *io_uring_get_socket(struct file *file)
-{
-#if defined(CONFIG_UNIX)
- if (file->f_op == &io_uring_fops) {
- struct io_ring_ctx *ctx = file->private_data;
-
- return ctx->ring_sock->sk;
- }
-#endif
- return NULL;
-}
-EXPORT_SYMBOL(io_uring_get_socket);
-
static void io_ring_ctx_ref_free(struct percpu_ref *ref)
{
struct io_ring_ctx *ctx = container_of(ref, struct io_ring_ctx, refs);
@@ -3794,6 +3781,11 @@ static const struct file_operations io_uring_fops = {
.fasync = io_uring_fasync,
};

+bool io_is_uring_fops(struct file *file)
+{
+ return file->f_op == &io_uring_fops;
+}
+
static int io_allocate_scq_urings(struct io_ring_ctx *ctx,
struct io_uring_params *p)
{
diff --git a/include/linux/fs.h b/include/linux/fs.h
index e009b52ab6b0..272f261894b1 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -3614,11 +3614,11 @@ extern int generic_fadvise(struct file *file, loff_t offset, loff_t len,
int advice);

#if defined(CONFIG_IO_URING)
-extern struct sock *io_uring_get_socket(struct file *file);
+bool io_is_uring_fops(struct file *file);
#else
-static inline struct sock *io_uring_get_socket(struct file *file)
+static inline bool io_is_uring_fops(struct file *file)
{
- return NULL;
+ return false;
}
#endif

diff --git a/net/core/scm.c b/net/core/scm.c
index 5525c14f33f1..a442bf63cd48 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -105,7 +105,7 @@ static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp)
if (fd < 0 || !(file = fget_raw(fd)))
return -EBADF;
/* don't allow io_uring files */
- if (io_uring_get_socket(file)) {
+ if (io_is_uring_fops(file)) {
fput(file);
return -EINVAL;
}
diff --git a/net/unix/scm.c b/net/unix/scm.c
index e881a6e78af5..51b623de3be5 100644
--- a/net/unix/scm.c
+++ b/net/unix/scm.c
@@ -33,10 +33,8 @@ struct sock *unix_get_socket(struct file *filp)
/* PF_UNIX ? */
if (s && sock->ops && sock->ops->family == PF_UNIX)
u_sock = s;
- } else {
- /* Could be an io_uring instance */
- u_sock = io_uring_get_socket(filp);
}
+
return u_sock;
}
EXPORT_SYMBOL(unix_get_socket);
--
2.43.0

[-- Attachment #3: 5.4-0002-io_uring-drop-any-code-related-to-SCM_RIGHTS.patch --]
[-- Type: text/x-patch, Size: 3287 bytes --]

From a21d37be81f8dc59d4cda4aac37312f0774e4b71 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Wed, 13 Mar 2024 18:36:18 -0600
Subject: [PATCH 2/2] io_uring: drop any code related to SCM_RIGHTS

Commit 6e5e6d274956305f1fc0340522b38f5f5be74bdb upstream.

This is dead code after we dropped support for passing io_uring fds
over SCM_RIGHTS, get rid of it.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
fs/io_uring.c | 47 +++--------------------------------------------
1 file changed, 3 insertions(+), 44 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index cd1858cc6320..2c793e4ccf09 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -63,7 +63,6 @@
#include <linux/net.h>
#include <net/sock.h>
#include <net/af_unix.h>
-#include <net/scm.h>
#include <linux/anon_inodes.h>
#include <linux/sched/mm.h>
#include <linux/uaccess.h>
@@ -264,10 +263,6 @@ struct io_ring_ctx {

struct async_list pending_async[2];

-#if defined(CONFIG_UNIX)
- struct socket *ring_sock;
-#endif
-
struct list_head task_list;
spinlock_t task_lock;
};
@@ -3067,20 +3062,10 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events,

static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
{
-#if defined(CONFIG_UNIX)
- if (ctx->ring_sock) {
- struct sock *sock = ctx->ring_sock->sk;
- struct sk_buff *skb;
-
- while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
- kfree_skb(skb);
- }
-#else
int i;

for (i = 0; i < ctx->nr_user_files; i++)
fput(ctx->user_files[i]);
-#endif
}

static int io_sqe_files_unregister(struct io_ring_ctx *ctx)
@@ -3575,13 +3560,6 @@ static void io_ring_ctx_free(struct io_ring_ctx *ctx)
io_sqe_files_unregister(ctx);
io_eventfd_unregister(ctx);

-#if defined(CONFIG_UNIX)
- if (ctx->ring_sock) {
- ctx->ring_sock->file = NULL; /* so that iput() is called */
- sock_release(ctx->ring_sock);
- }
-#endif
-
io_mem_free(ctx->rings);
io_mem_free(ctx->sq_sqes);

@@ -3833,45 +3811,26 @@ static int io_allocate_scq_urings(struct io_ring_ctx *ctx,
/*
* Allocate an anonymous fd, this is what constitutes the application
* visible backing of an io_uring instance. The application mmaps this
- * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
- * we have to tie this fd to a socket for file garbage collection purposes.
+ * fd to gain access to the SQ/CQ ring details.
*/
static int io_uring_get_fd(struct io_ring_ctx *ctx)
{
struct file *file;
int ret;

-#if defined(CONFIG_UNIX)
- ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
- &ctx->ring_sock);
- if (ret)
- return ret;
-#endif
-
ret = get_unused_fd_flags(O_RDWR | O_CLOEXEC);
if (ret < 0)
- goto err;
+ return ret;

file = anon_inode_getfile("[io_uring]", &io_uring_fops, ctx,
O_RDWR | O_CLOEXEC);
if (IS_ERR(file)) {
put_unused_fd(ret);
- ret = PTR_ERR(file);
- goto err;
+ return PTR_ERR(file);
}

-#if defined(CONFIG_UNIX)
- ctx->ring_sock->file = file;
- ctx->ring_sock->sk->sk_user_data = ctx;
-#endif
fd_install(ret, file);
return ret;
-err:
-#if defined(CONFIG_UNIX)
- sock_release(ctx->ring_sock);
- ctx->ring_sock = NULL;
-#endif
- return ret;
}

static int io_uring_create(unsigned entries, struct io_uring_params *p)
--
2.43.0

[-- Attachment #4: 6.7-0001-io_uring-unix-drop-usage-of-io_uring-socket.patch --]
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From 25b0645afe6459437da6cff71546984597f209da Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Tue, 19 Dec 2023 12:30:43 -0700
Subject: [PATCH 1/2] io_uring/unix: drop usage of io_uring socket

Commit a4104821ad651d8a0b374f0b2474c345bbb42f82 upstream.

Since we no longer allow sending io_uring fds over SCM_RIGHTS, move to
using io_is_uring_fops() to detect whether this is a io_uring fd or not.
With that done, kill off io_uring_get_socket() as nobody calls it
anymore.

This is in preparation to yanking out the rest of the core related to
unix gc with io_uring.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
include/linux/io_uring.h | 9 +++++----
io_uring/io_uring.c | 13 -------------
io_uring/io_uring.h | 1 -
net/core/scm.c | 2 +-
net/unix/scm.c | 4 +---
5 files changed, 7 insertions(+), 22 deletions(-)

diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h
index aefb73eeeebf..b3a32687f514 100644
--- a/include/linux/io_uring.h
+++ b/include/linux/io_uring.h
@@ -93,6 +93,7 @@ int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags);
void io_uring_cmd_mark_cancelable(struct io_uring_cmd *cmd,
unsigned int issue_flags);
struct task_struct *io_uring_cmd_get_task(struct io_uring_cmd *cmd);
+bool io_is_uring_fops(struct file *file);
#else
static inline int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
struct iov_iter *iter, void *ioucmd)
@@ -111,10 +112,6 @@ static inline void io_uring_cmd_do_in_task_lazy(struct io_uring_cmd *ioucmd,
void (*task_work_cb)(struct io_uring_cmd *, unsigned))
{
}
-static inline struct sock *io_uring_get_socket(struct file *file)
-{
- return NULL;
-}
static inline void io_uring_task_cancel(void)
{
}
@@ -141,6 +138,10 @@ static inline struct task_struct *io_uring_cmd_get_task(struct io_uring_cmd *cmd
{
return NULL;
}
+static inline bool io_is_uring_fops(struct file *file)
+{
+ return false;
+}
#endif

#endif
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 59f5791c90c3..06bd8795a87d 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -177,19 +177,6 @@ static struct ctl_table kernel_io_uring_disabled_table[] = {
};
#endif

-struct sock *io_uring_get_socket(struct file *file)
-{
-#if defined(CONFIG_UNIX)
- if (io_is_uring_fops(file)) {
- struct io_ring_ctx *ctx = file->private_data;
-
- return ctx->ring_sock->sk;
- }
-#endif
- return NULL;
-}
-EXPORT_SYMBOL(io_uring_get_socket);
-
static inline void io_submit_flush_completions(struct io_ring_ctx *ctx)
{
if (!wq_list_empty(&ctx->submit_state.compl_reqs) ||
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index c9992cd7f138..0d66a7058dbe 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -61,7 +61,6 @@ struct file *io_file_get_fixed(struct io_kiocb *req, int fd,
unsigned issue_flags);

void __io_req_task_work_add(struct io_kiocb *req, unsigned flags);
-bool io_is_uring_fops(struct file *file);
bool io_alloc_async_data(struct io_kiocb *req);
void io_req_task_queue(struct io_kiocb *req);
void io_queue_iowq(struct io_kiocb *req, struct io_tw_state *ts_dont_use);
diff --git a/net/core/scm.c b/net/core/scm.c
index 7dc47c17d863..737917c7ac62 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -105,7 +105,7 @@ static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp)
if (fd < 0 || !(file = fget_raw(fd)))
return -EBADF;
/* don't allow io_uring files */
- if (io_uring_get_socket(file)) {
+ if (io_is_uring_fops(file)) {
fput(file);
return -EINVAL;
}
diff --git a/net/unix/scm.c b/net/unix/scm.c
index 6ff628f2349f..822ce0d0d791 100644
--- a/net/unix/scm.c
+++ b/net/unix/scm.c
@@ -35,10 +35,8 @@ struct sock *unix_get_socket(struct file *filp)
/* PF_UNIX ? */
if (s && ops && ops->family == PF_UNIX)
u_sock = s;
- } else {
- /* Could be an io_uring instance */
- u_sock = io_uring_get_socket(filp);
}
+
return u_sock;
}
EXPORT_SYMBOL(unix_get_socket);
--
2.43.0

[-- Attachment #5: 6.7-0002-io_uring-drop-any-code-related-to-SCM_RIGHTS.patch --]
[-- Type: text/x-patch, Size: 11051 bytes --]

From e742473ca70a1fb2492451bf4959d0e94a0c1c7c Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Tue, 19 Dec 2023 12:36:34 -0700
Subject: [PATCH 2/2] io_uring: drop any code related to SCM_RIGHTS

Commit 6e5e6d274956305f1fc0340522b38f5f5be74bdb upstream.

This is dead code after we dropped support for passing io_uring fds
over SCM_RIGHTS, get rid of it.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
include/linux/io_uring_types.h | 3 -
io_uring/filetable.c | 11 +--
io_uring/io_uring.c | 32 +------
io_uring/rsrc.c | 169 +--------------------------------
io_uring/rsrc.h | 15 ---
5 files changed, 10 insertions(+), 220 deletions(-)

diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index 239a4f68801b..335eca49dc8b 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -358,9 +358,6 @@ struct io_ring_ctx {
struct wait_queue_head rsrc_quiesce_wq;
unsigned rsrc_quiesce;

- #if defined(CONFIG_UNIX)
- struct socket *ring_sock;
- #endif
/* hashed buffered write serialization */
struct io_wq_hash *hash_map;

diff --git a/io_uring/filetable.c b/io_uring/filetable.c
index e7d749991de4..6e86e6188dbe 100644
--- a/io_uring/filetable.c
+++ b/io_uring/filetable.c
@@ -87,13 +87,10 @@ static int io_install_fixed_file(struct io_ring_ctx *ctx, struct file *file,
io_file_bitmap_clear(&ctx->file_table, slot_index);
}

- ret = io_scm_file_account(ctx, file);
- if (!ret) {
- *io_get_tag_slot(ctx->file_data, slot_index) = 0;
- io_fixed_file_set(file_slot, file);
- io_file_bitmap_set(&ctx->file_table, slot_index);
- }
- return ret;
+ *io_get_tag_slot(ctx->file_data, slot_index) = 0;
+ io_fixed_file_set(file_slot, file);
+ io_file_bitmap_set(&ctx->file_table, slot_index);
+ return 0;
}

int __io_fixed_fd_install(struct io_ring_ctx *ctx, struct file *file,
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 06bd8795a87d..f8d145fb40bb 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -60,7 +60,6 @@
#include <linux/net.h>
#include <net/sock.h>
#include <net/af_unix.h>
-#include <net/scm.h>
#include <linux/anon_inodes.h>
#include <linux/sched/mm.h>
#include <linux/uaccess.h>
@@ -2939,13 +2938,6 @@ static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx)
io_rsrc_node_destroy(ctx, ctx->rsrc_node);

WARN_ON_ONCE(!list_empty(&ctx->rsrc_ref_list));
-
-#if defined(CONFIG_UNIX)
- if (ctx->ring_sock) {
- ctx->ring_sock->file = NULL; /* so that iput() is called */
- sock_release(ctx->ring_sock);
- }
-#endif
WARN_ON_ONCE(!list_empty(&ctx->ltimeout_list));

io_alloc_cache_free(&ctx->rsrc_node_cache, io_rsrc_node_cache_free);
@@ -3867,32 +3859,12 @@ static int io_uring_install_fd(struct file *file)
/*
* Allocate an anonymous fd, this is what constitutes the application
* visible backing of an io_uring instance. The application mmaps this
- * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
- * we have to tie this fd to a socket for file garbage collection purposes.
+ * fd to gain access to the SQ/CQ ring details.
*/
static struct file *io_uring_get_file(struct io_ring_ctx *ctx)
{
- struct file *file;
-#if defined(CONFIG_UNIX)
- int ret;
-
- ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
- &ctx->ring_sock);
- if (ret)
- return ERR_PTR(ret);
-#endif
-
- file = anon_inode_getfile_secure("[io_uring]", &io_uring_fops, ctx,
+ return anon_inode_getfile_secure("[io_uring]", &io_uring_fops, ctx,
O_RDWR | O_CLOEXEC, NULL);
-#if defined(CONFIG_UNIX)
- if (IS_ERR(file)) {
- sock_release(ctx->ring_sock);
- ctx->ring_sock = NULL;
- } else {
- ctx->ring_sock->file = file;
- }
-#endif
- return file;
}

static __cold int io_uring_create(unsigned entries, struct io_uring_params *p,
diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index f521c5965a93..4818b79231dd 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -24,7 +24,6 @@ struct io_rsrc_update {
};

static void io_rsrc_buf_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc);
-static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc);
static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov,
struct io_mapped_ubuf **pimu,
struct page **last_hpage);
@@ -157,7 +156,7 @@ static void io_rsrc_put_work(struct io_rsrc_node *node)

switch (node->type) {
case IORING_RSRC_FILE:
- io_rsrc_file_put(node->ctx, prsrc);
+ fput(prsrc->file);
break;
case IORING_RSRC_BUFFER:
io_rsrc_buf_put(node->ctx, prsrc);
@@ -402,23 +401,13 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
break;
}
/*
- * Don't allow io_uring instances to be registered. If
- * UNIX isn't enabled, then this causes a reference
- * cycle and this instance can never get freed. If UNIX
- * is enabled we'll handle it just fine, but there's
- * still no point in allowing a ring fd as it doesn't
- * support regular read/write anyway.
+ * Don't allow io_uring instances to be registered.
*/
if (io_is_uring_fops(file)) {
fput(file);
err = -EBADF;
break;
}
- err = io_scm_file_account(ctx, file);
- if (err) {
- fput(file);
- break;
- }
*io_get_tag_slot(data, i) = tag;
io_fixed_file_set(file_slot, file);
io_file_bitmap_set(&ctx->file_table, i);
@@ -675,22 +664,12 @@ void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
for (i = 0; i < ctx->nr_user_files; i++) {
struct file *file = io_file_from_index(&ctx->file_table, i);

- /* skip scm accounted files, they'll be freed by ->ring_sock */
- if (!file || io_file_need_scm(file))
+ if (!file)
continue;
io_file_bitmap_clear(&ctx->file_table, i);
fput(file);
}

-#if defined(CONFIG_UNIX)
- if (ctx->ring_sock) {
- struct sock *sock = ctx->ring_sock->sk;
- struct sk_buff *skb;
-
- while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
- kfree_skb(skb);
- }
-#endif
io_free_file_tables(&ctx->file_table);
io_file_table_set_alloc_range(ctx, 0, 0);
io_rsrc_data_free(ctx->file_data);
@@ -718,137 +697,6 @@ int io_sqe_files_unregister(struct io_ring_ctx *ctx)
return ret;
}

-/*
- * Ensure the UNIX gc is aware of our file set, so we are certain that
- * the io_uring can be safely unregistered on process exit, even if we have
- * loops in the file referencing. We account only files that can hold other
- * files because otherwise they can't form a loop and so are not interesting
- * for GC.
- */
-int __io_scm_file_account(struct io_ring_ctx *ctx, struct file *file)
-{
-#if defined(CONFIG_UNIX)
- struct sock *sk = ctx->ring_sock->sk;
- struct sk_buff_head *head = &sk->sk_receive_queue;
- struct scm_fp_list *fpl;
- struct sk_buff *skb;
-
- if (likely(!io_file_need_scm(file)))
- return 0;
-
- /*
- * See if we can merge this file into an existing skb SCM_RIGHTS
- * file set. If there's no room, fall back to allocating a new skb
- * and filling it in.
- */
- spin_lock_irq(&head->lock);
- skb = skb_peek(head);
- if (skb && UNIXCB(skb).fp->count < SCM_MAX_FD)
- __skb_unlink(skb, head);
- else
- skb = NULL;
- spin_unlock_irq(&head->lock);
-
- if (!skb) {
- fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
- if (!fpl)
- return -ENOMEM;
-
- skb = alloc_skb(0, GFP_KERNEL);
- if (!skb) {
- kfree(fpl);
- return -ENOMEM;
- }
-
- fpl->user = get_uid(current_user());
- fpl->max = SCM_MAX_FD;
- fpl->count = 0;
-
- UNIXCB(skb).fp = fpl;
- skb->sk = sk;
- skb->destructor = io_uring_destruct_scm;
- refcount_add(skb->truesize, &sk->sk_wmem_alloc);
- }
-
- fpl = UNIXCB(skb).fp;
- fpl->fp[fpl->count++] = get_file(file);
- unix_inflight(fpl->user, file);
- skb_queue_head(head, skb);
- fput(file);
-#endif
- return 0;
-}
-
-static __cold void io_rsrc_file_scm_put(struct io_ring_ctx *ctx, struct file *file)
-{
-#if defined(CONFIG_UNIX)
- struct sock *sock = ctx->ring_sock->sk;
- struct sk_buff_head list, *head = &sock->sk_receive_queue;
- struct sk_buff *skb;
- int i;
-
- __skb_queue_head_init(&list);
-
- /*
- * Find the skb that holds this file in its SCM_RIGHTS. When found,
- * remove this entry and rearrange the file array.
- */
- skb = skb_dequeue(head);
- while (skb) {
- struct scm_fp_list *fp;
-
- fp = UNIXCB(skb).fp;
- for (i = 0; i < fp->count; i++) {
- int left;
-
- if (fp->fp[i] != file)
- continue;
-
- unix_notinflight(fp->user, fp->fp[i]);
- left = fp->count - 1 - i;
- if (left) {
- memmove(&fp->fp[i], &fp->fp[i + 1],
- left * sizeof(struct file *));
- }
- fp->count--;
- if (!fp->count) {
- kfree_skb(skb);
- skb = NULL;
- } else {
- __skb_queue_tail(&list, skb);
- }
- fput(file);
- file = NULL;
- break;
- }
-
- if (!file)
- break;
-
- __skb_queue_tail(&list, skb);
-
- skb = skb_dequeue(head);
- }
-
- if (skb_peek(&list)) {
- spin_lock_irq(&head->lock);
- while ((skb = __skb_dequeue(&list)) != NULL)
- __skb_queue_tail(head, skb);
- spin_unlock_irq(&head->lock);
- }
-#endif
-}
-
-static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
-{
- struct file *file = prsrc->file;
-
- if (likely(!io_file_need_scm(file)))
- fput(file);
- else
- io_rsrc_file_scm_put(ctx, file);
-}
-
int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
unsigned nr_args, u64 __user *tags)
{
@@ -897,21 +745,12 @@ int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
goto fail;

/*
- * Don't allow io_uring instances to be registered. If UNIX
- * isn't enabled, then this causes a reference cycle and this
- * instance can never get freed. If UNIX is enabled we'll
- * handle it just fine, but there's still no point in allowing
- * a ring fd as it doesn't support regular read/write anyway.
+ * Don't allow io_uring instances to be registered.
*/
if (io_is_uring_fops(file)) {
fput(file);
goto fail;
}
- ret = io_scm_file_account(ctx, file);
- if (ret) {
- fput(file);
- goto fail;
- }
file_slot = io_fixed_file_slot(&ctx->file_table, i);
io_fixed_file_set(file_slot, file);
io_file_bitmap_set(&ctx->file_table, i);
diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
index 08ac0d8e07ef..7238b9cfe33b 100644
--- a/io_uring/rsrc.h
+++ b/io_uring/rsrc.h
@@ -75,21 +75,6 @@ int io_sqe_files_unregister(struct io_ring_ctx *ctx);
int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
unsigned nr_args, u64 __user *tags);

-int __io_scm_file_account(struct io_ring_ctx *ctx, struct file *file);
-
-static inline bool io_file_need_scm(struct file *filp)
-{
- return false;
-}
-
-static inline int io_scm_file_account(struct io_ring_ctx *ctx,
- struct file *file)
-{
- if (likely(!io_file_need_scm(file)))
- return 0;
- return __io_scm_file_account(ctx, file);
-}
-
int io_register_files_update(struct io_ring_ctx *ctx, void __user *arg,
unsigned nr_args);
int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg,
--
2.43.0

[-- Attachment #6: 6.6-0002-io_uring-drop-any-code-related-to-SCM_RIGHTS.patch --]
[-- Type: text/x-patch, Size: 10962 bytes --]

From cbe948d42e1ff43e77d60f21823d3d798f92835e Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Tue, 19 Dec 2023 12:36:34 -0700
Subject: [PATCH 2/2] io_uring: drop any code related to SCM_RIGHTS

This is dead code after we dropped support for passing io_uring fds
over SCM_RIGHTS, get rid of it.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
include/linux/io_uring_types.h | 3 -
io_uring/filetable.c | 11 +--
io_uring/io_uring.c | 32 +------
io_uring/rsrc.c | 169 +--------------------------------
io_uring/rsrc.h | 15 ---
5 files changed, 10 insertions(+), 220 deletions(-)

diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index 5fd664fb71c8..731beb3198c4 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -347,9 +347,6 @@ struct io_ring_ctx {

struct list_head io_buffers_pages;

- #if defined(CONFIG_UNIX)
- struct socket *ring_sock;
- #endif
/* hashed buffered write serialization */
struct io_wq_hash *hash_map;

diff --git a/io_uring/filetable.c b/io_uring/filetable.c
index e7d749991de4..6e86e6188dbe 100644
--- a/io_uring/filetable.c
+++ b/io_uring/filetable.c
@@ -87,13 +87,10 @@ static int io_install_fixed_file(struct io_ring_ctx *ctx, struct file *file,
io_file_bitmap_clear(&ctx->file_table, slot_index);
}

- ret = io_scm_file_account(ctx, file);
- if (!ret) {
- *io_get_tag_slot(ctx->file_data, slot_index) = 0;
- io_fixed_file_set(file_slot, file);
- io_file_bitmap_set(&ctx->file_table, slot_index);
- }
- return ret;
+ *io_get_tag_slot(ctx->file_data, slot_index) = 0;
+ io_fixed_file_set(file_slot, file);
+ io_file_bitmap_set(&ctx->file_table, slot_index);
+ return 0;
}

int __io_fixed_fd_install(struct io_ring_ctx *ctx, struct file *file,
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 747d2a6ecab8..2744d72f1085 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -60,7 +60,6 @@
#include <linux/net.h>
#include <net/sock.h>
#include <net/af_unix.h>
-#include <net/scm.h>
#include <linux/anon_inodes.h>
#include <linux/sched/mm.h>
#include <linux/uaccess.h>
@@ -2931,13 +2930,6 @@ static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx)
io_rsrc_node_destroy(ctx, ctx->rsrc_node);

WARN_ON_ONCE(!list_empty(&ctx->rsrc_ref_list));
-
-#if defined(CONFIG_UNIX)
- if (ctx->ring_sock) {
- ctx->ring_sock->file = NULL; /* so that iput() is called */
- sock_release(ctx->ring_sock);
- }
-#endif
WARN_ON_ONCE(!list_empty(&ctx->ltimeout_list));

io_alloc_cache_free(&ctx->rsrc_node_cache, io_rsrc_node_cache_free);
@@ -3825,32 +3817,12 @@ static int io_uring_install_fd(struct file *file)
/*
* Allocate an anonymous fd, this is what constitutes the application
* visible backing of an io_uring instance. The application mmaps this
- * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
- * we have to tie this fd to a socket for file garbage collection purposes.
+ * fd to gain access to the SQ/CQ ring details.
*/
static struct file *io_uring_get_file(struct io_ring_ctx *ctx)
{
- struct file *file;
-#if defined(CONFIG_UNIX)
- int ret;
-
- ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
- &ctx->ring_sock);
- if (ret)
- return ERR_PTR(ret);
-#endif
-
- file = anon_inode_getfile_secure("[io_uring]", &io_uring_fops, ctx,
+ return anon_inode_getfile_secure("[io_uring]", &io_uring_fops, ctx,
O_RDWR | O_CLOEXEC, NULL);
-#if defined(CONFIG_UNIX)
- if (IS_ERR(file)) {
- sock_release(ctx->ring_sock);
- ctx->ring_sock = NULL;
- } else {
- ctx->ring_sock->file = file;
- }
-#endif
- return file;
}

static __cold int io_uring_create(unsigned entries, struct io_uring_params *p,
diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index dde501abd719..95230921b16d 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -24,7 +24,6 @@ struct io_rsrc_update {
};

static void io_rsrc_buf_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc);
-static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc);
static int io_sqe_buffer_register(struct io_ring_ctx *ctx, struct iovec *iov,
struct io_mapped_ubuf **pimu,
struct page **last_hpage);
@@ -157,7 +156,7 @@ static void io_rsrc_put_work(struct io_rsrc_node *node)

switch (node->type) {
case IORING_RSRC_FILE:
- io_rsrc_file_put(node->ctx, prsrc);
+ fput(prsrc->file);
break;
case IORING_RSRC_BUFFER:
io_rsrc_buf_put(node->ctx, prsrc);
@@ -402,23 +401,13 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
break;
}
/*
- * Don't allow io_uring instances to be registered. If
- * UNIX isn't enabled, then this causes a reference
- * cycle and this instance can never get freed. If UNIX
- * is enabled we'll handle it just fine, but there's
- * still no point in allowing a ring fd as it doesn't
- * support regular read/write anyway.
+ * Don't allow io_uring instances to be registered.
*/
if (io_is_uring_fops(file)) {
fput(file);
err = -EBADF;
break;
}
- err = io_scm_file_account(ctx, file);
- if (err) {
- fput(file);
- break;
- }
*io_get_tag_slot(data, i) = tag;
io_fixed_file_set(file_slot, file);
io_file_bitmap_set(&ctx->file_table, i);
@@ -675,22 +664,12 @@ void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
for (i = 0; i < ctx->nr_user_files; i++) {
struct file *file = io_file_from_index(&ctx->file_table, i);

- /* skip scm accounted files, they'll be freed by ->ring_sock */
- if (!file || io_file_need_scm(file))
+ if (!file)
continue;
io_file_bitmap_clear(&ctx->file_table, i);
fput(file);
}

-#if defined(CONFIG_UNIX)
- if (ctx->ring_sock) {
- struct sock *sock = ctx->ring_sock->sk;
- struct sk_buff *skb;
-
- while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
- kfree_skb(skb);
- }
-#endif
io_free_file_tables(&ctx->file_table);
io_file_table_set_alloc_range(ctx, 0, 0);
io_rsrc_data_free(ctx->file_data);
@@ -718,137 +697,6 @@ int io_sqe_files_unregister(struct io_ring_ctx *ctx)
return ret;
}

-/*
- * Ensure the UNIX gc is aware of our file set, so we are certain that
- * the io_uring can be safely unregistered on process exit, even if we have
- * loops in the file referencing. We account only files that can hold other
- * files because otherwise they can't form a loop and so are not interesting
- * for GC.
- */
-int __io_scm_file_account(struct io_ring_ctx *ctx, struct file *file)
-{
-#if defined(CONFIG_UNIX)
- struct sock *sk = ctx->ring_sock->sk;
- struct sk_buff_head *head = &sk->sk_receive_queue;
- struct scm_fp_list *fpl;
- struct sk_buff *skb;
-
- if (likely(!io_file_need_scm(file)))
- return 0;
-
- /*
- * See if we can merge this file into an existing skb SCM_RIGHTS
- * file set. If there's no room, fall back to allocating a new skb
- * and filling it in.
- */
- spin_lock_irq(&head->lock);
- skb = skb_peek(head);
- if (skb && UNIXCB(skb).fp->count < SCM_MAX_FD)
- __skb_unlink(skb, head);
- else
- skb = NULL;
- spin_unlock_irq(&head->lock);
-
- if (!skb) {
- fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
- if (!fpl)
- return -ENOMEM;
-
- skb = alloc_skb(0, GFP_KERNEL);
- if (!skb) {
- kfree(fpl);
- return -ENOMEM;
- }
-
- fpl->user = get_uid(current_user());
- fpl->max = SCM_MAX_FD;
- fpl->count = 0;
-
- UNIXCB(skb).fp = fpl;
- skb->sk = sk;
- skb->destructor = io_uring_destruct_scm;
- refcount_add(skb->truesize, &sk->sk_wmem_alloc);
- }
-
- fpl = UNIXCB(skb).fp;
- fpl->fp[fpl->count++] = get_file(file);
- unix_inflight(fpl->user, file);
- skb_queue_head(head, skb);
- fput(file);
-#endif
- return 0;
-}
-
-static __cold void io_rsrc_file_scm_put(struct io_ring_ctx *ctx, struct file *file)
-{
-#if defined(CONFIG_UNIX)
- struct sock *sock = ctx->ring_sock->sk;
- struct sk_buff_head list, *head = &sock->sk_receive_queue;
- struct sk_buff *skb;
- int i;
-
- __skb_queue_head_init(&list);
-
- /*
- * Find the skb that holds this file in its SCM_RIGHTS. When found,
- * remove this entry and rearrange the file array.
- */
- skb = skb_dequeue(head);
- while (skb) {
- struct scm_fp_list *fp;
-
- fp = UNIXCB(skb).fp;
- for (i = 0; i < fp->count; i++) {
- int left;
-
- if (fp->fp[i] != file)
- continue;
-
- unix_notinflight(fp->user, fp->fp[i]);
- left = fp->count - 1 - i;
- if (left) {
- memmove(&fp->fp[i], &fp->fp[i + 1],
- left * sizeof(struct file *));
- }
- fp->count--;
- if (!fp->count) {
- kfree_skb(skb);
- skb = NULL;
- } else {
- __skb_queue_tail(&list, skb);
- }
- fput(file);
- file = NULL;
- break;
- }
-
- if (!file)
- break;
-
- __skb_queue_tail(&list, skb);
-
- skb = skb_dequeue(head);
- }
-
- if (skb_peek(&list)) {
- spin_lock_irq(&head->lock);
- while ((skb = __skb_dequeue(&list)) != NULL)
- __skb_queue_tail(head, skb);
- spin_unlock_irq(&head->lock);
- }
-#endif
-}
-
-static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
-{
- struct file *file = prsrc->file;
-
- if (likely(!io_file_need_scm(file)))
- fput(file);
- else
- io_rsrc_file_scm_put(ctx, file);
-}
-
int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
unsigned nr_args, u64 __user *tags)
{
@@ -897,21 +745,12 @@ int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
goto fail;

/*
- * Don't allow io_uring instances to be registered. If UNIX
- * isn't enabled, then this causes a reference cycle and this
- * instance can never get freed. If UNIX is enabled we'll
- * handle it just fine, but there's still no point in allowing
- * a ring fd as it doesn't support regular read/write anyway.
+ * Don't allow io_uring instances to be registered.
*/
if (io_is_uring_fops(file)) {
fput(file);
goto fail;
}
- ret = io_scm_file_account(ctx, file);
- if (ret) {
- fput(file);
- goto fail;
- }
file_slot = io_fixed_file_slot(&ctx->file_table, i);
io_fixed_file_set(file_slot, file);
io_file_bitmap_set(&ctx->file_table, i);
diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
index 08ac0d8e07ef..7238b9cfe33b 100644
--- a/io_uring/rsrc.h
+++ b/io_uring/rsrc.h
@@ -75,21 +75,6 @@ int io_sqe_files_unregister(struct io_ring_ctx *ctx);
int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
unsigned nr_args, u64 __user *tags);

-int __io_scm_file_account(struct io_ring_ctx *ctx, struct file *file);
-
-static inline bool io_file_need_scm(struct file *filp)
-{
- return false;
-}
-
-static inline int io_scm_file_account(struct io_ring_ctx *ctx,
- struct file *file)
-{
- if (likely(!io_file_need_scm(file)))
- return 0;
- return __io_scm_file_account(ctx, file);
-}
-
int io_register_files_update(struct io_ring_ctx *ctx, void __user *arg,
unsigned nr_args);
int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg,
--
2.43.0

[-- Attachment #7: 6.6-0001-io_uring-unix-drop-usage-of-io_uring-socket.patch --]
[-- Type: text/x-patch, Size: 4367 bytes --]

From b706187d02eacef15922de5fafedd65bc2db0576 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Tue, 19 Dec 2023 12:30:43 -0700
Subject: [PATCH 1/2] io_uring/unix: drop usage of io_uring socket

Commit a4104821ad651d8a0b374f0b2474c345bbb42f82 upstream.

Since we no longer allow sending io_uring fds over SCM_RIGHTS, move to
using io_is_uring_fops() to detect whether this is a io_uring fd or not.
With that done, kill off io_uring_get_socket() as nobody calls it
anymore.

This is in preparation to yanking out the rest of the core related to
unix gc with io_uring.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
include/linux/io_uring.h | 10 +++++-----
io_uring/io_uring.c | 13 -------------
io_uring/io_uring.h | 1 -
net/core/scm.c | 2 +-
net/unix/scm.c | 4 +---
5 files changed, 7 insertions(+), 23 deletions(-)

diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h
index 106cdc55ff3b..f99ff6de926c 100644
--- a/include/linux/io_uring.h
+++ b/include/linux/io_uring.h
@@ -46,7 +46,6 @@ int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
struct iov_iter *iter, void *ioucmd);
void io_uring_cmd_done(struct io_uring_cmd *cmd, ssize_t ret, ssize_t res2,
unsigned issue_flags);
-struct sock *io_uring_get_socket(struct file *file);
void __io_uring_cancel(bool cancel_all);
void __io_uring_free(struct task_struct *tsk);
void io_uring_unreg_ringfd(void);
@@ -82,6 +81,7 @@ static inline void io_uring_free(struct task_struct *tsk)
__io_uring_free(tsk);
}
int io_uring_cmd_sock(struct io_uring_cmd *cmd, unsigned int issue_flags);
+bool io_is_uring_fops(struct file *file);
#else
static inline int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
struct iov_iter *iter, void *ioucmd)
@@ -100,10 +100,6 @@ static inline void io_uring_cmd_do_in_task_lazy(struct io_uring_cmd *ioucmd,
void (*task_work_cb)(struct io_uring_cmd *, unsigned))
{
}
-static inline struct sock *io_uring_get_socket(struct file *file)
-{
- return NULL;
-}
static inline void io_uring_task_cancel(void)
{
}
@@ -122,6 +118,10 @@ static inline int io_uring_cmd_sock(struct io_uring_cmd *cmd,
{
return -EOPNOTSUPP;
}
+static inline bool io_is_uring_fops(struct file *file)
+{
+ return false;
+}
#endif

#endif
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index ea772a02c140..747d2a6ecab8 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -175,19 +175,6 @@ static struct ctl_table kernel_io_uring_disabled_table[] = {
};
#endif

-struct sock *io_uring_get_socket(struct file *file)
-{
-#if defined(CONFIG_UNIX)
- if (io_is_uring_fops(file)) {
- struct io_ring_ctx *ctx = file->private_data;
-
- return ctx->ring_sock->sk;
- }
-#endif
- return NULL;
-}
-EXPORT_SYMBOL(io_uring_get_socket);
-
static inline void io_submit_flush_completions(struct io_ring_ctx *ctx)
{
if (!wq_list_empty(&ctx->submit_state.compl_reqs) ||
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index c8cba7831083..411c883b37a9 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -61,7 +61,6 @@ struct file *io_file_get_fixed(struct io_kiocb *req, int fd,
unsigned issue_flags);

void __io_req_task_work_add(struct io_kiocb *req, unsigned flags);
-bool io_is_uring_fops(struct file *file);
bool io_alloc_async_data(struct io_kiocb *req);
void io_req_task_queue(struct io_kiocb *req);
void io_queue_iowq(struct io_kiocb *req, struct io_tw_state *ts_dont_use);
diff --git a/net/core/scm.c b/net/core/scm.c
index 7dc47c17d863..737917c7ac62 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -105,7 +105,7 @@ static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp)
if (fd < 0 || !(file = fget_raw(fd)))
return -EBADF;
/* don't allow io_uring files */
- if (io_uring_get_socket(file)) {
+ if (io_is_uring_fops(file)) {
fput(file);
return -EINVAL;
}
diff --git a/net/unix/scm.c b/net/unix/scm.c
index 6ff628f2349f..822ce0d0d791 100644
--- a/net/unix/scm.c
+++ b/net/unix/scm.c
@@ -35,10 +35,8 @@ struct sock *unix_get_socket(struct file *filp)
/* PF_UNIX ? */
if (s && ops && ops->family == PF_UNIX)
u_sock = s;
- } else {
- /* Could be an io_uring instance */
- u_sock = io_uring_get_socket(filp);
}
+
return u_sock;
}
EXPORT_SYMBOL(unix_get_socket);
--
2.43.0

[-- Attachment #8: 6.1-0001-io_uring-unix-drop-usage-of-io_uring-socket.patch --]
[-- Type: text/x-patch, Size: 4272 bytes --]

From 42d0449f65e6632ddc638929c53676fb776d8412 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Wed, 13 Mar 2024 18:10:12 -0600
Subject: [PATCH 1/2] io_uring/unix: drop usage of io_uring socket

Commit a4104821ad651d8a0b374f0b2474c345bbb42f82 upstream.

Since we no longer allow sending io_uring fds over SCM_RIGHTS, move to
using io_is_uring_fops() to detect whether this is a io_uring fd or not.
With that done, kill off io_uring_get_socket() as nobody calls it
anymore.

This is in preparation to yanking out the rest of the core related to
unix gc with io_uring.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
include/linux/io_uring.h | 10 +++++-----
io_uring/io_uring.c | 13 -------------
io_uring/io_uring.h | 1 -
net/core/scm.c | 2 +-
net/unix/scm.c | 4 +---
5 files changed, 7 insertions(+), 23 deletions(-)

diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h
index a1484cdb3158..a8f3058448ea 100644
--- a/include/linux/io_uring.h
+++ b/include/linux/io_uring.h
@@ -42,11 +42,11 @@ void io_uring_cmd_done(struct io_uring_cmd *cmd, ssize_t ret, ssize_t res2,
unsigned issue_flags);
void io_uring_cmd_complete_in_task(struct io_uring_cmd *ioucmd,
void (*task_work_cb)(struct io_uring_cmd *, unsigned));
-struct sock *io_uring_get_socket(struct file *file);
void __io_uring_cancel(bool cancel_all);
void __io_uring_free(struct task_struct *tsk);
void io_uring_unreg_ringfd(void);
const char *io_uring_get_opcode(u8 opcode);
+bool io_is_uring_fops(struct file *file);

static inline void io_uring_files_cancel(void)
{
@@ -71,6 +71,10 @@ static inline int io_uring_cmd_import_fixed(u64 ubuf, unsigned long len, int rw,
{
return -EOPNOTSUPP;
}
+static inline bool io_is_uring_fops(struct file *file)
+{
+ return false;
+}
static inline void io_uring_cmd_done(struct io_uring_cmd *cmd, ssize_t ret,
ssize_t ret2, unsigned issue_flags)
{
@@ -79,10 +83,6 @@ static inline void io_uring_cmd_complete_in_task(struct io_uring_cmd *ioucmd,
void (*task_work_cb)(struct io_uring_cmd *, unsigned))
{
}
-static inline struct sock *io_uring_get_socket(struct file *file)
-{
- return NULL;
-}
static inline void io_uring_task_cancel(void)
{
}
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 35894955b454..cf7dd62da0e3 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -153,19 +153,6 @@ static void __io_submit_flush_completions(struct io_ring_ctx *ctx);

static struct kmem_cache *req_cachep;

-struct sock *io_uring_get_socket(struct file *file)
-{
-#if defined(CONFIG_UNIX)
- if (io_is_uring_fops(file)) {
- struct io_ring_ctx *ctx = file->private_data;
-
- return ctx->ring_sock->sk;
- }
-#endif
- return NULL;
-}
-EXPORT_SYMBOL(io_uring_get_socket);
-
static inline void io_submit_flush_completions(struct io_ring_ctx *ctx)
{
if (!wq_list_empty(&ctx->submit_state.compl_reqs))
diff --git a/io_uring/io_uring.h b/io_uring/io_uring.h
index 019600570ee4..59e6f755f12c 100644
--- a/io_uring/io_uring.h
+++ b/io_uring/io_uring.h
@@ -52,7 +52,6 @@ static inline bool io_req_ffs_set(struct io_kiocb *req)
}

void __io_req_task_work_add(struct io_kiocb *req, bool allow_local);
-bool io_is_uring_fops(struct file *file);
bool io_alloc_async_data(struct io_kiocb *req);
void io_req_task_queue(struct io_kiocb *req);
void io_queue_iowq(struct io_kiocb *req, bool *dont_use);
diff --git a/net/core/scm.c b/net/core/scm.c
index e762a4b8a1d2..a877c4ef4c25 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -105,7 +105,7 @@ static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp)
if (fd < 0 || !(file = fget_raw(fd)))
return -EBADF;
/* don't allow io_uring files */
- if (io_uring_get_socket(file)) {
+ if (io_is_uring_fops(file)) {
fput(file);
return -EINVAL;
}
diff --git a/net/unix/scm.c b/net/unix/scm.c
index e8e2a00bb0f5..d1048b4c2baa 100644
--- a/net/unix/scm.c
+++ b/net/unix/scm.c
@@ -34,10 +34,8 @@ struct sock *unix_get_socket(struct file *filp)
/* PF_UNIX ? */
if (s && sock->ops && sock->ops->family == PF_UNIX)
u_sock = s;
- } else {
- /* Could be an io_uring instance */
- u_sock = io_uring_get_socket(filp);
}
+
return u_sock;
}
EXPORT_SYMBOL(unix_get_socket);
--
2.43.0

[-- Attachment #9: 6.1-0002-io_uring-drop-any-code-related-to-SCM_RIGHTS.patch --]
[-- Type: text/x-patch, Size: 9727 bytes --]

From 083974002b6f45bb84090a9aed025d8a3d8479cb Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Wed, 13 Mar 2024 18:15:05 -0600
Subject: [PATCH 2/2] io_uring: drop any code related to SCM_RIGHTS

Commit 6e5e6d274956305f1fc0340522b38f5f5be74bdb upstream.

This is dead code after we dropped support for passing io_uring fds
over SCM_RIGHTS, get rid of it.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
include/linux/io_uring_types.h | 3 -
io_uring/filetable.c | 10 +--
io_uring/io_uring.c | 31 +------
io_uring/rsrc.c | 151 +--------------------------------
io_uring/rsrc.h | 15 ----
5 files changed, 8 insertions(+), 202 deletions(-)

diff --git a/include/linux/io_uring_types.h b/include/linux/io_uring_types.h
index f5b687a787a3..37aeea266ebb 100644
--- a/include/linux/io_uring_types.h
+++ b/include/linux/io_uring_types.h
@@ -330,9 +330,6 @@ struct io_ring_ctx {

struct list_head io_buffers_pages;

- #if defined(CONFIG_UNIX)
- struct socket *ring_sock;
- #endif
/* hashed buffered write serialization */
struct io_wq_hash *hash_map;

diff --git a/io_uring/filetable.c b/io_uring/filetable.c
index b80614e7d605..4660cb89ea9f 100644
--- a/io_uring/filetable.c
+++ b/io_uring/filetable.c
@@ -95,12 +95,10 @@ static int io_install_fixed_file(struct io_ring_ctx *ctx, struct file *file,
needs_switch = true;
}

- ret = io_scm_file_account(ctx, file);
- if (!ret) {
- *io_get_tag_slot(ctx->file_data, slot_index) = 0;
- io_fixed_file_set(file_slot, file);
- io_file_bitmap_set(&ctx->file_table, slot_index);
- }
+ *io_get_tag_slot(ctx->file_data, slot_index) = 0;
+ io_fixed_file_set(file_slot, file);
+ io_file_bitmap_set(&ctx->file_table, slot_index);
+ return 0;
err:
if (needs_switch)
io_rsrc_node_switch(ctx, ctx->file_data);
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index cf7dd62da0e3..415248c1f82c 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -60,7 +60,6 @@
#include <linux/net.h>
#include <net/sock.h>
#include <net/af_unix.h>
-#include <net/scm.h>
#include <linux/anon_inodes.h>
#include <linux/sched/mm.h>
#include <linux/uaccess.h>
@@ -2628,12 +2627,6 @@ static __cold void io_ring_ctx_free(struct io_ring_ctx *ctx)
WARN_ON_ONCE(!list_empty(&ctx->rsrc_ref_list));
WARN_ON_ONCE(!llist_empty(&ctx->rsrc_put_llist));

-#if defined(CONFIG_UNIX)
- if (ctx->ring_sock) {
- ctx->ring_sock->file = NULL; /* so that iput() is called */
- sock_release(ctx->ring_sock);
- }
-#endif
WARN_ON_ONCE(!list_empty(&ctx->ltimeout_list));

if (ctx->mm_account) {
@@ -3438,32 +3431,12 @@ static int io_uring_install_fd(struct io_ring_ctx *ctx, struct file *file)
/*
* Allocate an anonymous fd, this is what constitutes the application
* visible backing of an io_uring instance. The application mmaps this
- * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
- * we have to tie this fd to a socket for file garbage collection purposes.
+ * fd to gain access to the SQ/CQ ring details.
*/
static struct file *io_uring_get_file(struct io_ring_ctx *ctx)
{
- struct file *file;
-#if defined(CONFIG_UNIX)
- int ret;
-
- ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
- &ctx->ring_sock);
- if (ret)
- return ERR_PTR(ret);
-#endif
-
- file = anon_inode_getfile_secure("[io_uring]", &io_uring_fops, ctx,
+ return anon_inode_getfile_secure("[io_uring]", &io_uring_fops, ctx,
O_RDWR | O_CLOEXEC, NULL);
-#if defined(CONFIG_UNIX)
- if (IS_ERR(file)) {
- sock_release(ctx->ring_sock);
- ctx->ring_sock = NULL;
- } else {
- ctx->ring_sock->file = file;
- }
-#endif
- return file;
}

static __cold int io_uring_create(unsigned entries, struct io_uring_params *p,
diff --git a/io_uring/rsrc.c b/io_uring/rsrc.c
index 7ada0339b387..ac658cfa89c6 100644
--- a/io_uring/rsrc.c
+++ b/io_uring/rsrc.c
@@ -494,11 +494,6 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx,
err = -EBADF;
break;
}
- err = io_scm_file_account(ctx, file);
- if (err) {
- fput(file);
- break;
- }
*io_get_tag_slot(data, i) = tag;
io_fixed_file_set(file_slot, file);
io_file_bitmap_set(&ctx->file_table, i);
@@ -762,22 +757,12 @@ void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
for (i = 0; i < ctx->nr_user_files; i++) {
struct file *file = io_file_from_index(&ctx->file_table, i);

- /* skip scm accounted files, they'll be freed by ->ring_sock */
- if (!file || io_file_need_scm(file))
+ if (!file)
continue;
io_file_bitmap_clear(&ctx->file_table, i);
fput(file);
}

-#if defined(CONFIG_UNIX)
- if (ctx->ring_sock) {
- struct sock *sock = ctx->ring_sock->sk;
- struct sk_buff *skb;
-
- while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
- kfree_skb(skb);
- }
-#endif
io_free_file_tables(&ctx->file_table);
io_file_table_set_alloc_range(ctx, 0, 0);
io_rsrc_data_free(ctx->file_data);
@@ -805,134 +790,11 @@ int io_sqe_files_unregister(struct io_ring_ctx *ctx)
return ret;
}

-/*
- * Ensure the UNIX gc is aware of our file set, so we are certain that
- * the io_uring can be safely unregistered on process exit, even if we have
- * loops in the file referencing. We account only files that can hold other
- * files because otherwise they can't form a loop and so are not interesting
- * for GC.
- */
-int __io_scm_file_account(struct io_ring_ctx *ctx, struct file *file)
-{
-#if defined(CONFIG_UNIX)
- struct sock *sk = ctx->ring_sock->sk;
- struct sk_buff_head *head = &sk->sk_receive_queue;
- struct scm_fp_list *fpl;
- struct sk_buff *skb;
-
- if (likely(!io_file_need_scm(file)))
- return 0;
-
- /*
- * See if we can merge this file into an existing skb SCM_RIGHTS
- * file set. If there's no room, fall back to allocating a new skb
- * and filling it in.
- */
- spin_lock_irq(&head->lock);
- skb = skb_peek(head);
- if (skb && UNIXCB(skb).fp->count < SCM_MAX_FD)
- __skb_unlink(skb, head);
- else
- skb = NULL;
- spin_unlock_irq(&head->lock);
-
- if (!skb) {
- fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
- if (!fpl)
- return -ENOMEM;
-
- skb = alloc_skb(0, GFP_KERNEL);
- if (!skb) {
- kfree(fpl);
- return -ENOMEM;
- }
-
- fpl->user = get_uid(current_user());
- fpl->max = SCM_MAX_FD;
- fpl->count = 0;
-
- UNIXCB(skb).fp = fpl;
- skb->sk = sk;
- skb->scm_io_uring = 1;
- skb->destructor = unix_destruct_scm;
- refcount_add(skb->truesize, &sk->sk_wmem_alloc);
- }
-
- fpl = UNIXCB(skb).fp;
- fpl->fp[fpl->count++] = get_file(file);
- unix_inflight(fpl->user, file);
- skb_queue_head(head, skb);
- fput(file);
-#endif
- return 0;
-}
-
static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
{
struct file *file = prsrc->file;
-#if defined(CONFIG_UNIX)
- struct sock *sock = ctx->ring_sock->sk;
- struct sk_buff_head list, *head = &sock->sk_receive_queue;
- struct sk_buff *skb;
- int i;
-
- if (!io_file_need_scm(file)) {
- fput(file);
- return;
- }
-
- __skb_queue_head_init(&list);
-
- /*
- * Find the skb that holds this file in its SCM_RIGHTS. When found,
- * remove this entry and rearrange the file array.
- */
- skb = skb_dequeue(head);
- while (skb) {
- struct scm_fp_list *fp;

- fp = UNIXCB(skb).fp;
- for (i = 0; i < fp->count; i++) {
- int left;
-
- if (fp->fp[i] != file)
- continue;
-
- unix_notinflight(fp->user, fp->fp[i]);
- left = fp->count - 1 - i;
- if (left) {
- memmove(&fp->fp[i], &fp->fp[i + 1],
- left * sizeof(struct file *));
- }
- fp->count--;
- if (!fp->count) {
- kfree_skb(skb);
- skb = NULL;
- } else {
- __skb_queue_tail(&list, skb);
- }
- fput(file);
- file = NULL;
- break;
- }
-
- if (!file)
- break;
-
- __skb_queue_tail(&list, skb);
-
- skb = skb_dequeue(head);
- }
-
- if (skb_peek(&list)) {
- spin_lock_irq(&head->lock);
- while ((skb = __skb_dequeue(&list)) != NULL)
- __skb_queue_tail(head, skb);
- spin_unlock_irq(&head->lock);
- }
-#else
fput(file);
-#endif
}

int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
@@ -986,21 +848,12 @@ int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
goto fail;

/*
- * Don't allow io_uring instances to be registered. If UNIX
- * isn't enabled, then this causes a reference cycle and this
- * instance can never get freed. If UNIX is enabled we'll
- * handle it just fine, but there's still no point in allowing
- * a ring fd as it doesn't support regular read/write anyway.
+ * Don't allow io_uring instances to be registered.
*/
if (io_is_uring_fops(file)) {
fput(file);
goto fail;
}
- ret = io_scm_file_account(ctx, file);
- if (ret) {
- fput(file);
- goto fail;
- }
file_slot = io_fixed_file_slot(&ctx->file_table, i);
io_fixed_file_set(file_slot, file);
io_file_bitmap_set(&ctx->file_table, i);
diff --git a/io_uring/rsrc.h b/io_uring/rsrc.h
index acaf8dad0540..85f145607c62 100644
--- a/io_uring/rsrc.h
+++ b/io_uring/rsrc.h
@@ -77,21 +77,6 @@ int io_sqe_files_unregister(struct io_ring_ctx *ctx);
int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
unsigned nr_args, u64 __user *tags);

-int __io_scm_file_account(struct io_ring_ctx *ctx, struct file *file);
-
-static inline bool io_file_need_scm(struct file *filp)
-{
- return false;
-}
-
-static inline int io_scm_file_account(struct io_ring_ctx *ctx,
- struct file *file)
-{
- if (likely(!io_file_need_scm(file)))
- return 0;
- return __io_scm_file_account(ctx, file);
-}
-
int io_register_files_update(struct io_ring_ctx *ctx, void __user *arg,
unsigned nr_args);
int io_register_rsrc_update(struct io_ring_ctx *ctx, void __user *arg,
--
2.43.0

[-- Attachment #10: 5.10-5.15-0002-io_uring-drop-any-code-related-to-SCM_RIGHTS.patch --]
[-- Type: text/x-patch, Size: 7401 bytes --]

From 63fcaffd0b3d0db784cbe3950549766936355e84 Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Wed, 13 Mar 2024 17:59:01 -0600
Subject: [PATCH 2/2] io_uring: drop any code related to SCM_RIGHTS

Commit 6e5e6d274956305f1fc0340522b38f5f5be74bdb upstream.

This is dead code after we dropped support for passing io_uring fds
over SCM_RIGHTS, get rid of it.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
io_uring/io_uring.c | 211 +-------------------------------------------
1 file changed, 3 insertions(+), 208 deletions(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 541e6a6985ec..386b32e6fd9a 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -62,7 +62,6 @@
#include <linux/net.h>
#include <net/sock.h>
#include <net/af_unix.h>
-#include <net/scm.h>
#include <linux/anon_inodes.h>
#include <linux/sched/mm.h>
#include <linux/uaccess.h>
@@ -440,9 +439,6 @@ struct io_ring_ctx {

/* Keep this last, we don't need it for the fast path */
struct {
- #if defined(CONFIG_UNIX)
- struct socket *ring_sock;
- #endif
/* hashed buffered write serialization */
struct io_wq_hash *hash_map;

@@ -8151,15 +8147,6 @@ static void io_free_file_tables(struct io_file_table *table)

static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
{
-#if defined(CONFIG_UNIX)
- if (ctx->ring_sock) {
- struct sock *sock = ctx->ring_sock->sk;
- struct sk_buff *skb;
-
- while ((skb = skb_dequeue(&sock->sk_receive_queue)) != NULL)
- kfree_skb(skb);
- }
-#else
int i;

for (i = 0; i < ctx->nr_user_files; i++) {
@@ -8169,7 +8156,6 @@ static void __io_sqe_files_unregister(struct io_ring_ctx *ctx)
if (file)
fput(file);
}
-#endif
io_free_file_tables(&ctx->file_table);
io_rsrc_data_free(ctx->file_data);
ctx->file_data = NULL;
@@ -8321,170 +8307,11 @@ static struct io_sq_data *io_get_sq_data(struct io_uring_params *p,
return sqd;
}

-#if defined(CONFIG_UNIX)
-/*
- * Ensure the UNIX gc is aware of our file set, so we are certain that
- * the io_uring can be safely unregistered on process exit, even if we have
- * loops in the file referencing.
- */
-static int __io_sqe_files_scm(struct io_ring_ctx *ctx, int nr, int offset)
-{
- struct sock *sk = ctx->ring_sock->sk;
- struct scm_fp_list *fpl;
- struct sk_buff *skb;
- int i, nr_files;
-
- fpl = kzalloc(sizeof(*fpl), GFP_KERNEL);
- if (!fpl)
- return -ENOMEM;
-
- skb = alloc_skb(0, GFP_KERNEL);
- if (!skb) {
- kfree(fpl);
- return -ENOMEM;
- }
-
- skb->sk = sk;
- skb->scm_io_uring = 1;
-
- nr_files = 0;
- fpl->user = get_uid(current_user());
- for (i = 0; i < nr; i++) {
- struct file *file = io_file_from_index(ctx, i + offset);
-
- if (!file)
- continue;
- fpl->fp[nr_files] = get_file(file);
- unix_inflight(fpl->user, fpl->fp[nr_files]);
- nr_files++;
- }
-
- if (nr_files) {
- fpl->max = SCM_MAX_FD;
- fpl->count = nr_files;
- UNIXCB(skb).fp = fpl;
- skb->destructor = unix_destruct_scm;
- refcount_add(skb->truesize, &sk->sk_wmem_alloc);
- skb_queue_head(&sk->sk_receive_queue, skb);
-
- for (i = 0; i < nr; i++) {
- struct file *file = io_file_from_index(ctx, i + offset);
-
- if (file)
- fput(file);
- }
- } else {
- kfree_skb(skb);
- free_uid(fpl->user);
- kfree(fpl);
- }
-
- return 0;
-}
-
-/*
- * If UNIX sockets are enabled, fd passing can cause a reference cycle which
- * causes regular reference counting to break down. We rely on the UNIX
- * garbage collection to take care of this problem for us.
- */
-static int io_sqe_files_scm(struct io_ring_ctx *ctx)
-{
- unsigned left, total;
- int ret = 0;
-
- total = 0;
- left = ctx->nr_user_files;
- while (left) {
- unsigned this_files = min_t(unsigned, left, SCM_MAX_FD);
-
- ret = __io_sqe_files_scm(ctx, this_files, total);
- if (ret)
- break;
- left -= this_files;
- total += this_files;
- }
-
- if (!ret)
- return 0;
-
- while (total < ctx->nr_user_files) {
- struct file *file = io_file_from_index(ctx, total);
-
- if (file)
- fput(file);
- total++;
- }
-
- return ret;
-}
-#else
-static int io_sqe_files_scm(struct io_ring_ctx *ctx)
-{
- return 0;
-}
-#endif
-
static void io_rsrc_file_put(struct io_ring_ctx *ctx, struct io_rsrc_put *prsrc)
{
struct file *file = prsrc->file;
-#if defined(CONFIG_UNIX)
- struct sock *sock = ctx->ring_sock->sk;
- struct sk_buff_head list, *head = &sock->sk_receive_queue;
- struct sk_buff *skb;
- int i;

- __skb_queue_head_init(&list);
-
- /*
- * Find the skb that holds this file in its SCM_RIGHTS. When found,
- * remove this entry and rearrange the file array.
- */
- skb = skb_dequeue(head);
- while (skb) {
- struct scm_fp_list *fp;
-
- fp = UNIXCB(skb).fp;
- for (i = 0; i < fp->count; i++) {
- int left;
-
- if (fp->fp[i] != file)
- continue;
-
- unix_notinflight(fp->user, fp->fp[i]);
- left = fp->count - 1 - i;
- if (left) {
- memmove(&fp->fp[i], &fp->fp[i + 1],
- left * sizeof(struct file *));
- }
- fp->count--;
- if (!fp->count) {
- kfree_skb(skb);
- skb = NULL;
- } else {
- __skb_queue_tail(&list, skb);
- }
- fput(file);
- file = NULL;
- break;
- }
-
- if (!file)
- break;
-
- __skb_queue_tail(&list, skb);
-
- skb = skb_dequeue(head);
- }
-
- if (skb_peek(&list)) {
- spin_lock_irq(&head->lock);
- while ((skb = __skb_dequeue(&list)) != NULL)
- __skb_queue_tail(head, skb);
- spin_unlock_irq(&head->lock);
- }
-#else
fput(file);
-#endif
}

static void __io_rsrc_put_work(struct io_rsrc_node *ref_node)
@@ -8595,12 +8422,6 @@ static int io_sqe_files_register(struct io_ring_ctx *ctx, void __user *arg,
io_fixed_file_set(io_fixed_file_slot(&ctx->file_table, i), file);
}

- ret = io_sqe_files_scm(ctx);
- if (ret) {
- __io_sqe_files_unregister(ctx);
- return ret;
- }
-
io_rsrc_node_switch(ctx, NULL);
return ret;
out_fput:
@@ -9557,12 +9378,6 @@ static void io_ring_ctx_free(struct io_ring_ctx *ctx)
WARN_ON_ONCE(!list_empty(&ctx->rsrc_ref_list));
WARN_ON_ONCE(!llist_empty(&ctx->rsrc_put_llist));

-#if defined(CONFIG_UNIX)
- if (ctx->ring_sock) {
- ctx->ring_sock->file = NULL; /* so that iput() is called */
- sock_release(ctx->ring_sock);
- }
-#endif
WARN_ON_ONCE(!list_empty(&ctx->ltimeout_list));

if (ctx->mm_account) {
@@ -10499,32 +10314,12 @@ static int io_uring_install_fd(struct io_ring_ctx *ctx, struct file *file)
/*
* Allocate an anonymous fd, this is what constitutes the application
* visible backing of an io_uring instance. The application mmaps this
- * fd to gain access to the SQ/CQ ring details. If UNIX sockets are enabled,
- * we have to tie this fd to a socket for file garbage collection purposes.
+ * fd to gain access to the SQ/CQ ring details.
*/
static struct file *io_uring_get_file(struct io_ring_ctx *ctx)
{
- struct file *file;
-#if defined(CONFIG_UNIX)
- int ret;
-
- ret = sock_create_kern(&init_net, PF_UNIX, SOCK_RAW, IPPROTO_IP,
- &ctx->ring_sock);
- if (ret)
- return ERR_PTR(ret);
-#endif
-
- file = anon_inode_getfile("[io_uring]", &io_uring_fops, ctx,
- O_RDWR | O_CLOEXEC);
-#if defined(CONFIG_UNIX)
- if (IS_ERR(file)) {
- sock_release(ctx->ring_sock);
- ctx->ring_sock = NULL;
- } else {
- ctx->ring_sock->file = file;
- }
-#endif
- return file;
+ return anon_inode_getfile("[io_uring]", &io_uring_fops, ctx,
+ O_RDWR | O_CLOEXEC);
}

static int io_uring_create(unsigned entries, struct io_uring_params *p,
--
2.43.0

[-- Attachment #11: 5.10-5.15-0001-io_uring-unix-drop-usage-of-io_uring-socket.patch --]
[-- Type: text/x-patch, Size: 3582 bytes --]

From 7c36fae9614f48c971c458f3bb12b97d3414abab Mon Sep 17 00:00:00 2001
From: Jens Axboe <axboe@kernel.dk>
Date: Wed, 13 Mar 2024 17:54:49 -0600
Subject: [PATCH 1/2] io_uring/unix: drop usage of io_uring socket

Commit a4104821ad651d8a0b374f0b2474c345bbb42f82 upstream.

Since we no longer allow sending io_uring fds over SCM_RIGHTS, move to
using io_is_uring_fops() to detect whether this is a io_uring fd or not.
With that done, kill off io_uring_get_socket() as nobody calls it
anymore.

This is in preparation to yanking out the rest of the core related to
unix gc with io_uring.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
include/linux/io_uring.h | 10 +++++-----
io_uring/io_uring.c | 18 +++++-------------
net/core/scm.c | 2 +-
net/unix/scm.c | 4 +---
4 files changed, 12 insertions(+), 22 deletions(-)

diff --git a/include/linux/io_uring.h b/include/linux/io_uring.h
index 649a4d7c241b..55d09f594cd1 100644
--- a/include/linux/io_uring.h
+++ b/include/linux/io_uring.h
@@ -6,9 +6,9 @@
#include <linux/xarray.h>

#if defined(CONFIG_IO_URING)
-struct sock *io_uring_get_socket(struct file *file);
void __io_uring_cancel(bool cancel_all);
void __io_uring_free(struct task_struct *tsk);
+bool io_is_uring_fops(struct file *file);

static inline void io_uring_files_cancel(void)
{
@@ -26,10 +26,6 @@ static inline void io_uring_free(struct task_struct *tsk)
__io_uring_free(tsk);
}
#else
-static inline struct sock *io_uring_get_socket(struct file *file)
-{
- return NULL;
-}
static inline void io_uring_task_cancel(void)
{
}
@@ -39,6 +35,10 @@ static inline void io_uring_files_cancel(void)
static inline void io_uring_free(struct task_struct *tsk)
{
}
+static inline bool io_is_uring_fops(struct file *file)
+{
+ return false;
+}
#endif

#endif
diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index 55fd6d98fe12..541e6a6985ec 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -1116,19 +1116,6 @@ static struct kmem_cache *req_cachep;

static const struct file_operations io_uring_fops;

-struct sock *io_uring_get_socket(struct file *file)
-{
-#if defined(CONFIG_UNIX)
- if (file->f_op == &io_uring_fops) {
- struct io_ring_ctx *ctx = file->private_data;
-
- return ctx->ring_sock->sk;
- }
-#endif
- return NULL;
-}
-EXPORT_SYMBOL(io_uring_get_socket);
-
static inline void io_tw_lock(struct io_ring_ctx *ctx, bool *locked)
{
if (!*locked) {
@@ -10445,6 +10432,11 @@ static const struct file_operations io_uring_fops = {
#endif
};

+bool io_is_uring_fops(struct file *file)
+{
+ return file->f_op == &io_uring_fops;
+}
+
static int io_allocate_scq_urings(struct io_ring_ctx *ctx,
struct io_uring_params *p)
{
diff --git a/net/core/scm.c b/net/core/scm.c
index e762a4b8a1d2..a877c4ef4c25 100644
--- a/net/core/scm.c
+++ b/net/core/scm.c
@@ -105,7 +105,7 @@ static int scm_fp_copy(struct cmsghdr *cmsg, struct scm_fp_list **fplp)
if (fd < 0 || !(file = fget_raw(fd)))
return -EBADF;
/* don't allow io_uring files */
- if (io_uring_get_socket(file)) {
+ if (io_is_uring_fops(file)) {
fput(file);
return -EINVAL;
}
diff --git a/net/unix/scm.c b/net/unix/scm.c
index e8e2a00bb0f5..d1048b4c2baa 100644
--- a/net/unix/scm.c
+++ b/net/unix/scm.c
@@ -34,10 +34,8 @@ struct sock *unix_get_socket(struct file *filp)
/* PF_UNIX ? */
if (s && sock->ops && sock->ops->family == PF_UNIX)
u_sock = s;
- } else {
- /* Could be an io_uring instance */
- u_sock = io_uring_get_socket(filp);
}
+
return u_sock;
}
EXPORT_SYMBOL(unix_get_socket);
--
2.43.0