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Message-Id: <1627715273202254@kroah.com>
Date: Sat, 31 Jul 2021 09:07:54 +0200
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-kernel@...r.kernel.org, akpm@...ux-foundation.org,
torvalds@...ux-foundation.org, stable@...r.kernel.org
Cc: lwn@....net, jslaby@...e.cz,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Subject: Re: Linux 4.19.200
diff --git a/Makefile b/Makefile
index f3ad63a089a1..a4ea351c4e5d 100644
--- a/Makefile
+++ b/Makefile
@@ -1,7 +1,7 @@
# SPDX-License-Identifier: GPL-2.0
VERSION = 4
PATCHLEVEL = 19
-SUBLEVEL = 199
+SUBLEVEL = 200
EXTRAVERSION =
NAME = "People's Front"
diff --git a/arch/arm/boot/dts/versatile-ab.dts b/arch/arm/boot/dts/versatile-ab.dts
index 6f4f60ba5429..990b7ef1800e 100644
--- a/arch/arm/boot/dts/versatile-ab.dts
+++ b/arch/arm/boot/dts/versatile-ab.dts
@@ -192,16 +192,15 @@
#size-cells = <1>;
ranges;
- vic: intc@...40000 {
+ vic: interrupt-controller@...40000 {
compatible = "arm,versatile-vic";
interrupt-controller;
#interrupt-cells = <1>;
reg = <0x10140000 0x1000>;
- clear-mask = <0xffffffff>;
valid-mask = <0xffffffff>;
};
- sic: intc@...03000 {
+ sic: interrupt-controller@...03000 {
compatible = "arm,versatile-sic";
interrupt-controller;
#interrupt-cells = <1>;
diff --git a/arch/arm/boot/dts/versatile-pb.dts b/arch/arm/boot/dts/versatile-pb.dts
index 06a0fdf24026..e7e751a858d8 100644
--- a/arch/arm/boot/dts/versatile-pb.dts
+++ b/arch/arm/boot/dts/versatile-pb.dts
@@ -7,7 +7,7 @@
amba {
/* The Versatile PB is using more SIC IRQ lines than the AB */
- sic: intc@...03000 {
+ sic: interrupt-controller@...03000 {
clear-mask = <0xffffffff>;
/*
* Valid interrupt lines mask according to
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 43fb4e296d8d..9cfc669b4a24 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -416,8 +416,6 @@ static void kvm_multiple_exception(struct kvm_vcpu *vcpu,
if (!vcpu->arch.exception.pending && !vcpu->arch.exception.injected) {
queue:
- if (has_error && !is_protmode(vcpu))
- has_error = false;
if (reinject) {
/*
* On vmentry, vcpu->arch.exception.pending is only
@@ -7114,6 +7112,13 @@ static void update_cr8_intercept(struct kvm_vcpu *vcpu)
kvm_x86_ops->update_cr8_intercept(vcpu, tpr, max_irr);
}
+static void kvm_inject_exception(struct kvm_vcpu *vcpu)
+{
+ if (vcpu->arch.exception.error_code && !is_protmode(vcpu))
+ vcpu->arch.exception.error_code = false;
+ kvm_x86_ops->queue_exception(vcpu);
+}
+
static int inject_pending_event(struct kvm_vcpu *vcpu)
{
int r;
@@ -7121,7 +7126,7 @@ static int inject_pending_event(struct kvm_vcpu *vcpu)
/* try to reinject previous events if any */
if (vcpu->arch.exception.injected)
- kvm_x86_ops->queue_exception(vcpu);
+ kvm_inject_exception(vcpu);
/*
* Do not inject an NMI or interrupt if there is a pending
* exception. Exceptions and interrupts are recognized at
@@ -7175,7 +7180,7 @@ static int inject_pending_event(struct kvm_vcpu *vcpu)
kvm_update_dr7(vcpu);
}
- kvm_x86_ops->queue_exception(vcpu);
+ kvm_inject_exception(vcpu);
}
/* Don't consider new event if we re-injected an event */
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index effc4c17e0fb..af5139eb96b5 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -48,7 +48,6 @@ enum scmi_error_codes {
SCMI_ERR_GENERIC = -8, /* Generic Error */
SCMI_ERR_HARDWARE = -9, /* Hardware Error */
SCMI_ERR_PROTOCOL = -10,/* Protocol Error */
- SCMI_ERR_MAX
};
/* List of all SCMI devices active in system */
@@ -168,8 +167,10 @@ static const int scmi_linux_errmap[] = {
static inline int scmi_to_linux_errno(int errno)
{
- if (errno < SCMI_SUCCESS && errno > SCMI_ERR_MAX)
- return scmi_linux_errmap[-errno];
+ int err_idx = -errno;
+
+ if (err_idx >= SCMI_SUCCESS && err_idx < ARRAY_SIZE(scmi_linux_errmap))
+ return scmi_linux_errmap[err_idx];
return -EIO;
}
@@ -628,8 +629,9 @@ static int scmi_xfer_info_init(struct scmi_info *sinfo)
struct scmi_xfers_info *info = &sinfo->minfo;
/* Pre-allocated messages, no more than what hdr.seq can support */
- if (WARN_ON(desc->max_msg >= MSG_TOKEN_MAX)) {
- dev_err(dev, "Maximum message of %d exceeds supported %ld\n",
+ if (WARN_ON(!desc->max_msg || desc->max_msg > MSG_TOKEN_MAX)) {
+ dev_err(dev,
+ "Invalid maximum messages %d, not in range [1 - %lu]\n",
desc->max_msg, MSG_TOKEN_MAX);
return -EINVAL;
}
diff --git a/drivers/iio/dac/ds4424.c b/drivers/iio/dac/ds4424.c
index 714a97f91319..ae9be792693b 100644
--- a/drivers/iio/dac/ds4424.c
+++ b/drivers/iio/dac/ds4424.c
@@ -236,12 +236,6 @@ static int ds4424_probe(struct i2c_client *client,
indio_dev->dev.of_node = client->dev.of_node;
indio_dev->dev.parent = &client->dev;
- if (!client->dev.of_node) {
- dev_err(&client->dev,
- "Not found DT.\n");
- return -ENODEV;
- }
-
data->vcc_reg = devm_regulator_get(&client->dev, "vcc");
if (IS_ERR(data->vcc_reg)) {
dev_err(&client->dev,
diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c
index 5a14f518cd97..61955a7c838b 100644
--- a/fs/cifs/smb2ops.c
+++ b/fs/cifs/smb2ops.c
@@ -386,8 +386,8 @@ parse_server_interfaces(struct network_interface_info_ioctl_rsp *buf,
p = buf;
while (bytes_left >= sizeof(*p)) {
info->speed = le64_to_cpu(p->LinkSpeed);
- info->rdma_capable = le32_to_cpu(p->Capability & RDMA_CAPABLE);
- info->rss_capable = le32_to_cpu(p->Capability & RSS_CAPABLE);
+ info->rdma_capable = le32_to_cpu(p->Capability & RDMA_CAPABLE) ? 1 : 0;
+ info->rss_capable = le32_to_cpu(p->Capability & RSS_CAPABLE) ? 1 : 0;
cifs_dbg(FYI, "%s: adding iface %zu\n", __func__, *iface_count);
cifs_dbg(FYI, "%s: speed %zu bps\n", __func__, info->speed);
diff --git a/fs/hfs/bfind.c b/fs/hfs/bfind.c
index 4af318fbda77..ef9498a6e88a 100644
--- a/fs/hfs/bfind.c
+++ b/fs/hfs/bfind.c
@@ -25,7 +25,19 @@ int hfs_find_init(struct hfs_btree *tree, struct hfs_find_data *fd)
fd->key = ptr + tree->max_key_len + 2;
hfs_dbg(BNODE_REFS, "find_init: %d (%p)\n",
tree->cnid, __builtin_return_address(0));
- mutex_lock(&tree->tree_lock);
+ switch (tree->cnid) {
+ case HFS_CAT_CNID:
+ mutex_lock_nested(&tree->tree_lock, CATALOG_BTREE_MUTEX);
+ break;
+ case HFS_EXT_CNID:
+ mutex_lock_nested(&tree->tree_lock, EXTENTS_BTREE_MUTEX);
+ break;
+ case HFS_ATTR_CNID:
+ mutex_lock_nested(&tree->tree_lock, ATTR_BTREE_MUTEX);
+ break;
+ default:
+ return -EINVAL;
+ }
return 0;
}
diff --git a/fs/hfs/bnode.c b/fs/hfs/bnode.c
index b63a4df7327b..c0a73a6ffb28 100644
--- a/fs/hfs/bnode.c
+++ b/fs/hfs/bnode.c
@@ -15,16 +15,31 @@
#include "btree.h"
-void hfs_bnode_read(struct hfs_bnode *node, void *buf,
- int off, int len)
+void hfs_bnode_read(struct hfs_bnode *node, void *buf, int off, int len)
{
struct page *page;
+ int pagenum;
+ int bytes_read;
+ int bytes_to_read;
+ void *vaddr;
off += node->page_offset;
- page = node->page[0];
+ pagenum = off >> PAGE_SHIFT;
+ off &= ~PAGE_MASK; /* compute page offset for the first page */
- memcpy(buf, kmap(page) + off, len);
- kunmap(page);
+ for (bytes_read = 0; bytes_read < len; bytes_read += bytes_to_read) {
+ if (pagenum >= node->tree->pages_per_bnode)
+ break;
+ page = node->page[pagenum];
+ bytes_to_read = min_t(int, len - bytes_read, PAGE_SIZE - off);
+
+ vaddr = kmap_atomic(page);
+ memcpy(buf + bytes_read, vaddr + off, bytes_to_read);
+ kunmap_atomic(vaddr);
+
+ pagenum++;
+ off = 0; /* page offset only applies to the first page */
+ }
}
u16 hfs_bnode_read_u16(struct hfs_bnode *node, int off)
diff --git a/fs/hfs/btree.h b/fs/hfs/btree.h
index dcc2aab1b2c4..25ac9a8bb57a 100644
--- a/fs/hfs/btree.h
+++ b/fs/hfs/btree.h
@@ -13,6 +13,13 @@ typedef int (*btree_keycmp)(const btree_key *, const btree_key *);
#define NODE_HASH_SIZE 256
+/* B-tree mutex nested subclasses */
+enum hfs_btree_mutex_classes {
+ CATALOG_BTREE_MUTEX,
+ EXTENTS_BTREE_MUTEX,
+ ATTR_BTREE_MUTEX,
+};
+
/* A HFS BTree held in memory */
struct hfs_btree {
struct super_block *sb;
diff --git a/fs/hfs/super.c b/fs/hfs/super.c
index 173876782f73..77b6f35a4aa9 100644
--- a/fs/hfs/super.c
+++ b/fs/hfs/super.c
@@ -427,14 +427,12 @@ static int hfs_fill_super(struct super_block *sb, void *data, int silent)
if (!res) {
if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) {
res = -EIO;
- goto bail;
+ goto bail_hfs_find;
}
hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength);
}
- if (res) {
- hfs_find_exit(&fd);
- goto bail_no_root;
- }
+ if (res)
+ goto bail_hfs_find;
res = -EINVAL;
root_inode = hfs_iget(sb, &fd.search_key->cat, &rec);
hfs_find_exit(&fd);
@@ -450,6 +448,8 @@ static int hfs_fill_super(struct super_block *sb, void *data, int silent)
/* everything's okay */
return 0;
+bail_hfs_find:
+ hfs_find_exit(&fd);
bail_no_root:
pr_err("get root inode failed\n");
bail:
diff --git a/include/net/af_unix.h b/include/net/af_unix.h
index a5ba41b3b867..7ec1cdb66be8 100644
--- a/include/net/af_unix.h
+++ b/include/net/af_unix.h
@@ -10,6 +10,7 @@
void unix_inflight(struct user_struct *user, struct file *fp);
void unix_notinflight(struct user_struct *user, struct file *fp);
+void unix_destruct_scm(struct sk_buff *skb);
void unix_gc(void);
void wait_for_unix_gc(void);
struct sock *unix_get_socket(struct file *filp);
diff --git a/include/net/busy_poll.h b/include/net/busy_poll.h
index cf8f792743ec..c76a5e9894da 100644
--- a/include/net/busy_poll.h
+++ b/include/net/busy_poll.h
@@ -48,7 +48,7 @@ static inline bool net_busy_loop_on(void)
static inline bool sk_can_busy_loop(const struct sock *sk)
{
- return sk->sk_ll_usec && !signal_pending(current);
+ return READ_ONCE(sk->sk_ll_usec) && !signal_pending(current);
}
bool sk_busy_loop_end(void *p, unsigned long start_time);
diff --git a/include/net/sctp/constants.h b/include/net/sctp/constants.h
index 48d74674d5e9..bc22e44ffcdf 100644
--- a/include/net/sctp/constants.h
+++ b/include/net/sctp/constants.h
@@ -348,8 +348,7 @@ enum {
#define SCTP_SCOPE_POLICY_MAX SCTP_SCOPE_POLICY_LINK
/* Based on IPv4 scoping <draft-stewart-tsvwg-sctp-ipv4-00.txt>,
- * SCTP IPv4 unusable addresses: 0.0.0.0/8, 224.0.0.0/4, 198.18.0.0/24,
- * 192.88.99.0/24.
+ * SCTP IPv4 unusable addresses: 0.0.0.0/8, 224.0.0.0/4, 192.88.99.0/24.
* Also, RFC 8.4, non-unicast addresses are not considered valid SCTP
* addresses.
*/
@@ -357,7 +356,6 @@ enum {
((htonl(INADDR_BROADCAST) == a) || \
ipv4_is_multicast(a) || \
ipv4_is_zeronet(a) || \
- ipv4_is_test_198(a) || \
ipv4_is_anycast_6to4(a))
/* Flags used for the bind address copy functions. */
diff --git a/kernel/workqueue.c b/kernel/workqueue.c
index f278e2f584fd..1573d1bf6300 100644
--- a/kernel/workqueue.c
+++ b/kernel/workqueue.c
@@ -3498,15 +3498,21 @@ static void pwq_unbound_release_workfn(struct work_struct *work)
unbound_release_work);
struct workqueue_struct *wq = pwq->wq;
struct worker_pool *pool = pwq->pool;
- bool is_last;
+ bool is_last = false;
- if (WARN_ON_ONCE(!(wq->flags & WQ_UNBOUND)))
- return;
+ /*
+ * when @pwq is not linked, it doesn't hold any reference to the
+ * @wq, and @wq is invalid to access.
+ */
+ if (!list_empty(&pwq->pwqs_node)) {
+ if (WARN_ON_ONCE(!(wq->flags & WQ_UNBOUND)))
+ return;
- mutex_lock(&wq->mutex);
- list_del_rcu(&pwq->pwqs_node);
- is_last = list_empty(&wq->pwqs);
- mutex_unlock(&wq->mutex);
+ mutex_lock(&wq->mutex);
+ list_del_rcu(&pwq->pwqs_node);
+ is_last = list_empty(&wq->pwqs);
+ mutex_unlock(&wq->mutex);
+ }
mutex_lock(&wq_pool_mutex);
put_unbound_pool(pool);
diff --git a/net/802/garp.c b/net/802/garp.c
index 7f50d47470bd..8e19f51833d6 100644
--- a/net/802/garp.c
+++ b/net/802/garp.c
@@ -206,6 +206,19 @@ static void garp_attr_destroy(struct garp_applicant *app, struct garp_attr *attr
kfree(attr);
}
+static void garp_attr_destroy_all(struct garp_applicant *app)
+{
+ struct rb_node *node, *next;
+ struct garp_attr *attr;
+
+ for (node = rb_first(&app->gid);
+ next = node ? rb_next(node) : NULL, node != NULL;
+ node = next) {
+ attr = rb_entry(node, struct garp_attr, node);
+ garp_attr_destroy(app, attr);
+ }
+}
+
static int garp_pdu_init(struct garp_applicant *app)
{
struct sk_buff *skb;
@@ -612,6 +625,7 @@ void garp_uninit_applicant(struct net_device *dev, struct garp_application *appl
spin_lock_bh(&app->lock);
garp_gid_event(app, GARP_EVENT_TRANSMIT_PDU);
+ garp_attr_destroy_all(app);
garp_pdu_queue(app);
spin_unlock_bh(&app->lock);
diff --git a/net/802/mrp.c b/net/802/mrp.c
index a808dd5bbb27..32f87d458f05 100644
--- a/net/802/mrp.c
+++ b/net/802/mrp.c
@@ -295,6 +295,19 @@ static void mrp_attr_destroy(struct mrp_applicant *app, struct mrp_attr *attr)
kfree(attr);
}
+static void mrp_attr_destroy_all(struct mrp_applicant *app)
+{
+ struct rb_node *node, *next;
+ struct mrp_attr *attr;
+
+ for (node = rb_first(&app->mad);
+ next = node ? rb_next(node) : NULL, node != NULL;
+ node = next) {
+ attr = rb_entry(node, struct mrp_attr, node);
+ mrp_attr_destroy(app, attr);
+ }
+}
+
static int mrp_pdu_init(struct mrp_applicant *app)
{
struct sk_buff *skb;
@@ -898,6 +911,7 @@ void mrp_uninit_applicant(struct net_device *dev, struct mrp_application *appl)
spin_lock_bh(&app->lock);
mrp_mad_event(app, MRP_EVENT_TX);
+ mrp_attr_destroy_all(app);
mrp_pdu_queue(app);
spin_unlock_bh(&app->lock);
diff --git a/net/Makefile b/net/Makefile
index bdaf53925acd..449fc0b221f8 100644
--- a/net/Makefile
+++ b/net/Makefile
@@ -18,7 +18,7 @@ obj-$(CONFIG_NETFILTER) += netfilter/
obj-$(CONFIG_INET) += ipv4/
obj-$(CONFIG_TLS) += tls/
obj-$(CONFIG_XFRM) += xfrm/
-obj-$(CONFIG_UNIX) += unix/
+obj-$(CONFIG_UNIX_SCM) += unix/
obj-$(CONFIG_NET) += ipv6/
obj-$(CONFIG_BPFILTER) += bpfilter/
obj-$(CONFIG_PACKET) += packet/
diff --git a/net/core/sock.c b/net/core/sock.c
index e6cbe137cb6f..956af38aa0d6 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -989,7 +989,7 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
if (val < 0)
ret = -EINVAL;
else
- sk->sk_ll_usec = val;
+ WRITE_ONCE(sk->sk_ll_usec, val);
}
break;
#endif
diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index dd5125658255..7207a9769f1a 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -412,7 +412,8 @@ static enum sctp_scope sctp_v4_scope(union sctp_addr *addr)
retval = SCTP_SCOPE_LINK;
} else if (ipv4_is_private_10(addr->v4.sin_addr.s_addr) ||
ipv4_is_private_172(addr->v4.sin_addr.s_addr) ||
- ipv4_is_private_192(addr->v4.sin_addr.s_addr)) {
+ ipv4_is_private_192(addr->v4.sin_addr.s_addr) ||
+ ipv4_is_test_198(addr->v4.sin_addr.s_addr)) {
retval = SCTP_SCOPE_PRIVATE;
} else {
retval = SCTP_SCOPE_GLOBAL;
diff --git a/net/unix/Kconfig b/net/unix/Kconfig
index 8b31ab85d050..3b9e450656a4 100644
--- a/net/unix/Kconfig
+++ b/net/unix/Kconfig
@@ -19,6 +19,11 @@ config UNIX
Say Y unless you know what you are doing.
+config UNIX_SCM
+ bool
+ depends on UNIX
+ default y
+
config UNIX_DIAG
tristate "UNIX: socket monitoring interface"
depends on UNIX
diff --git a/net/unix/Makefile b/net/unix/Makefile
index ffd0a275c3a7..54e58cc4f945 100644
--- a/net/unix/Makefile
+++ b/net/unix/Makefile
@@ -10,3 +10,5 @@ unix-$(CONFIG_SYSCTL) += sysctl_net_unix.o
obj-$(CONFIG_UNIX_DIAG) += unix_diag.o
unix_diag-y := diag.o
+
+obj-$(CONFIG_UNIX_SCM) += scm.o
diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 53fe5ada5a83..98c253afa0db 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -119,6 +119,8 @@
#include <linux/freezer.h>
#include <linux/file.h>
+#include "scm.h"
+
struct hlist_head unix_socket_table[2 * UNIX_HASH_SIZE];
EXPORT_SYMBOL_GPL(unix_socket_table);
DEFINE_SPINLOCK(unix_table_lock);
@@ -1515,65 +1517,51 @@ static int unix_getname(struct socket *sock, struct sockaddr *uaddr, int peer)
return err;
}
-static void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb)
-{
- int i;
-
- scm->fp = UNIXCB(skb).fp;
- UNIXCB(skb).fp = NULL;
-
- for (i = scm->fp->count-1; i >= 0; i--)
- unix_notinflight(scm->fp->user, scm->fp->fp[i]);
-}
-
-static void unix_destruct_scm(struct sk_buff *skb)
-{
- struct scm_cookie scm;
- memset(&scm, 0, sizeof(scm));
- scm.pid = UNIXCB(skb).pid;
- if (UNIXCB(skb).fp)
- unix_detach_fds(&scm, skb);
-
- /* Alas, it calls VFS */
- /* So fscking what? fput() had been SMP-safe since the last Summer */
- scm_destroy(&scm);
- sock_wfree(skb);
-}
-
-/*
- * The "user->unix_inflight" variable is protected by the garbage
- * collection lock, and we just read it locklessly here. If you go
- * over the limit, there might be a tiny race in actually noticing
- * it across threads. Tough.
- */
-static inline bool too_many_unix_fds(struct task_struct *p)
-{
- struct user_struct *user = current_user();
-
- if (unlikely(user->unix_inflight > task_rlimit(p, RLIMIT_NOFILE)))
- return !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN);
- return false;
-}
-
-static int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
+static void unix_peek_fds(struct scm_cookie *scm, struct sk_buff *skb)
{
- int i;
-
- if (too_many_unix_fds(current))
- return -ETOOMANYREFS;
+ scm->fp = scm_fp_dup(UNIXCB(skb).fp);
/*
- * Need to duplicate file references for the sake of garbage
- * collection. Otherwise a socket in the fps might become a
- * candidate for GC while the skb is not yet queued.
+ * Garbage collection of unix sockets starts by selecting a set of
+ * candidate sockets which have reference only from being in flight
+ * (total_refs == inflight_refs). This condition is checked once during
+ * the candidate collection phase, and candidates are marked as such, so
+ * that non-candidates can later be ignored. While inflight_refs is
+ * protected by unix_gc_lock, total_refs (file count) is not, hence this
+ * is an instantaneous decision.
+ *
+ * Once a candidate, however, the socket must not be reinstalled into a
+ * file descriptor while the garbage collection is in progress.
+ *
+ * If the above conditions are met, then the directed graph of
+ * candidates (*) does not change while unix_gc_lock is held.
+ *
+ * Any operations that changes the file count through file descriptors
+ * (dup, close, sendmsg) does not change the graph since candidates are
+ * not installed in fds.
+ *
+ * Dequeing a candidate via recvmsg would install it into an fd, but
+ * that takes unix_gc_lock to decrement the inflight count, so it's
+ * serialized with garbage collection.
+ *
+ * MSG_PEEK is special in that it does not change the inflight count,
+ * yet does install the socket into an fd. The following lock/unlock
+ * pair is to ensure serialization with garbage collection. It must be
+ * done between incrementing the file count and installing the file into
+ * an fd.
+ *
+ * If garbage collection starts after the barrier provided by the
+ * lock/unlock, then it will see the elevated refcount and not mark this
+ * as a candidate. If a garbage collection is already in progress
+ * before the file count was incremented, then the lock/unlock pair will
+ * ensure that garbage collection is finished before progressing to
+ * installing the fd.
+ *
+ * (*) A -> B where B is on the queue of A or B is on the queue of C
+ * which is on the queue of listening socket A.
*/
- UNIXCB(skb).fp = scm_fp_dup(scm->fp);
- if (!UNIXCB(skb).fp)
- return -ENOMEM;
-
- for (i = scm->fp->count - 1; i >= 0; i--)
- unix_inflight(scm->fp->user, scm->fp->fp[i]);
- return 0;
+ spin_lock(&unix_gc_lock);
+ spin_unlock(&unix_gc_lock);
}
static int unix_scm_to_skb(struct scm_cookie *scm, struct sk_buff *skb, bool send_fds)
@@ -2201,7 +2189,7 @@ static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
sk_peek_offset_fwd(sk, size);
if (UNIXCB(skb).fp)
- scm.fp = scm_fp_dup(UNIXCB(skb).fp);
+ unix_peek_fds(&scm, skb);
}
err = (flags & MSG_TRUNC) ? skb->len - skip : size;
@@ -2442,7 +2430,7 @@ static int unix_stream_read_generic(struct unix_stream_read_state *state,
/* It is questionable, see note in unix_dgram_recvmsg.
*/
if (UNIXCB(skb).fp)
- scm.fp = scm_fp_dup(UNIXCB(skb).fp);
+ unix_peek_fds(&scm, skb);
sk_peek_offset_fwd(sk, chunk);
diff --git a/net/unix/garbage.c b/net/unix/garbage.c
index c36757e72844..8bbe1b8e4ff7 100644
--- a/net/unix/garbage.c
+++ b/net/unix/garbage.c
@@ -86,77 +86,13 @@
#include <net/scm.h>
#include <net/tcp_states.h>
+#include "scm.h"
+
/* Internal data structures and random procedures: */
-static LIST_HEAD(gc_inflight_list);
static LIST_HEAD(gc_candidates);
-static DEFINE_SPINLOCK(unix_gc_lock);
static DECLARE_WAIT_QUEUE_HEAD(unix_gc_wait);
-unsigned int unix_tot_inflight;
-
-struct sock *unix_get_socket(struct file *filp)
-{
- struct sock *u_sock = NULL;
- struct inode *inode = file_inode(filp);
-
- /* Socket ? */
- if (S_ISSOCK(inode->i_mode) && !(filp->f_mode & FMODE_PATH)) {
- struct socket *sock = SOCKET_I(inode);
- struct sock *s = sock->sk;
-
- /* PF_UNIX ? */
- if (s && sock->ops && sock->ops->family == PF_UNIX)
- u_sock = s;
- }
- return u_sock;
-}
-
-/* Keep the number of times in flight count for the file
- * descriptor if it is for an AF_UNIX socket.
- */
-
-void unix_inflight(struct user_struct *user, struct file *fp)
-{
- struct sock *s = unix_get_socket(fp);
-
- spin_lock(&unix_gc_lock);
-
- if (s) {
- struct unix_sock *u = unix_sk(s);
-
- if (atomic_long_inc_return(&u->inflight) == 1) {
- BUG_ON(!list_empty(&u->link));
- list_add_tail(&u->link, &gc_inflight_list);
- } else {
- BUG_ON(list_empty(&u->link));
- }
- unix_tot_inflight++;
- }
- user->unix_inflight++;
- spin_unlock(&unix_gc_lock);
-}
-
-void unix_notinflight(struct user_struct *user, struct file *fp)
-{
- struct sock *s = unix_get_socket(fp);
-
- spin_lock(&unix_gc_lock);
-
- if (s) {
- struct unix_sock *u = unix_sk(s);
-
- BUG_ON(!atomic_long_read(&u->inflight));
- BUG_ON(list_empty(&u->link));
-
- if (atomic_long_dec_and_test(&u->inflight))
- list_del_init(&u->link);
- unix_tot_inflight--;
- }
- user->unix_inflight--;
- spin_unlock(&unix_gc_lock);
-}
-
static void scan_inflight(struct sock *x, void (*func)(struct unix_sock *),
struct sk_buff_head *hitlist)
{
diff --git a/net/unix/scm.c b/net/unix/scm.c
new file mode 100644
index 000000000000..83413ade7983
--- /dev/null
+++ b/net/unix/scm.c
@@ -0,0 +1,148 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/socket.h>
+#include <linux/net.h>
+#include <linux/fs.h>
+#include <net/af_unix.h>
+#include <net/scm.h>
+#include <linux/init.h>
+
+#include "scm.h"
+
+unsigned int unix_tot_inflight;
+EXPORT_SYMBOL(unix_tot_inflight);
+
+LIST_HEAD(gc_inflight_list);
+EXPORT_SYMBOL(gc_inflight_list);
+
+DEFINE_SPINLOCK(unix_gc_lock);
+EXPORT_SYMBOL(unix_gc_lock);
+
+struct sock *unix_get_socket(struct file *filp)
+{
+ struct sock *u_sock = NULL;
+ struct inode *inode = file_inode(filp);
+
+ /* Socket ? */
+ if (S_ISSOCK(inode->i_mode) && !(filp->f_mode & FMODE_PATH)) {
+ struct socket *sock = SOCKET_I(inode);
+ struct sock *s = sock->sk;
+
+ /* PF_UNIX ? */
+ if (s && sock->ops && sock->ops->family == PF_UNIX)
+ u_sock = s;
+ }
+ return u_sock;
+}
+EXPORT_SYMBOL(unix_get_socket);
+
+/* Keep the number of times in flight count for the file
+ * descriptor if it is for an AF_UNIX socket.
+ */
+void unix_inflight(struct user_struct *user, struct file *fp)
+{
+ struct sock *s = unix_get_socket(fp);
+
+ spin_lock(&unix_gc_lock);
+
+ if (s) {
+ struct unix_sock *u = unix_sk(s);
+
+ if (atomic_long_inc_return(&u->inflight) == 1) {
+ BUG_ON(!list_empty(&u->link));
+ list_add_tail(&u->link, &gc_inflight_list);
+ } else {
+ BUG_ON(list_empty(&u->link));
+ }
+ unix_tot_inflight++;
+ }
+ user->unix_inflight++;
+ spin_unlock(&unix_gc_lock);
+}
+
+void unix_notinflight(struct user_struct *user, struct file *fp)
+{
+ struct sock *s = unix_get_socket(fp);
+
+ spin_lock(&unix_gc_lock);
+
+ if (s) {
+ struct unix_sock *u = unix_sk(s);
+
+ BUG_ON(!atomic_long_read(&u->inflight));
+ BUG_ON(list_empty(&u->link));
+
+ if (atomic_long_dec_and_test(&u->inflight))
+ list_del_init(&u->link);
+ unix_tot_inflight--;
+ }
+ user->unix_inflight--;
+ spin_unlock(&unix_gc_lock);
+}
+
+/*
+ * The "user->unix_inflight" variable is protected by the garbage
+ * collection lock, and we just read it locklessly here. If you go
+ * over the limit, there might be a tiny race in actually noticing
+ * it across threads. Tough.
+ */
+static inline bool too_many_unix_fds(struct task_struct *p)
+{
+ struct user_struct *user = current_user();
+
+ if (unlikely(user->unix_inflight > task_rlimit(p, RLIMIT_NOFILE)))
+ return !capable(CAP_SYS_RESOURCE) && !capable(CAP_SYS_ADMIN);
+ return false;
+}
+
+int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb)
+{
+ int i;
+
+ if (too_many_unix_fds(current))
+ return -ETOOMANYREFS;
+
+ /*
+ * Need to duplicate file references for the sake of garbage
+ * collection. Otherwise a socket in the fps might become a
+ * candidate for GC while the skb is not yet queued.
+ */
+ UNIXCB(skb).fp = scm_fp_dup(scm->fp);
+ if (!UNIXCB(skb).fp)
+ return -ENOMEM;
+
+ for (i = scm->fp->count - 1; i >= 0; i--)
+ unix_inflight(scm->fp->user, scm->fp->fp[i]);
+ return 0;
+}
+EXPORT_SYMBOL(unix_attach_fds);
+
+void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb)
+{
+ int i;
+
+ scm->fp = UNIXCB(skb).fp;
+ UNIXCB(skb).fp = NULL;
+
+ for (i = scm->fp->count-1; i >= 0; i--)
+ unix_notinflight(scm->fp->user, scm->fp->fp[i]);
+}
+EXPORT_SYMBOL(unix_detach_fds);
+
+void unix_destruct_scm(struct sk_buff *skb)
+{
+ struct scm_cookie scm;
+
+ memset(&scm, 0, sizeof(scm));
+ scm.pid = UNIXCB(skb).pid;
+ if (UNIXCB(skb).fp)
+ unix_detach_fds(&scm, skb);
+
+ /* Alas, it calls VFS */
+ /* So fscking what? fput() had been SMP-safe since the last Summer */
+ scm_destroy(&scm);
+ sock_wfree(skb);
+}
+EXPORT_SYMBOL(unix_destruct_scm);
diff --git a/net/unix/scm.h b/net/unix/scm.h
new file mode 100644
index 000000000000..5a255a477f16
--- /dev/null
+++ b/net/unix/scm.h
@@ -0,0 +1,10 @@
+#ifndef NET_UNIX_SCM_H
+#define NET_UNIX_SCM_H
+
+extern struct list_head gc_inflight_list;
+extern spinlock_t unix_gc_lock;
+
+int unix_attach_fds(struct scm_cookie *scm, struct sk_buff *skb);
+void unix_detach_fds(struct scm_cookie *scm, struct sk_buff *skb);
+
+#endif
diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
index 16d42b2de424..1963440f6725 100644
--- a/tools/testing/selftests/vm/userfaultfd.c
+++ b/tools/testing/selftests/vm/userfaultfd.c
@@ -131,7 +131,7 @@ static void anon_allocate_area(void **alloc_area)
{
*alloc_area = mmap(NULL, nr_pages * page_size, PROT_READ | PROT_WRITE,
MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
- if (*alloc_area == MAP_FAILED)
+ if (*alloc_area == MAP_FAILED) {
fprintf(stderr, "mmap of anonymous memory failed");
*alloc_area = NULL;
}
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