Revision 84811412464d66fcf73661a279aa1d7985166495 authored by Prashant Malani on 20 November 2019, 19:40:21 UTC, committed by David S. Miller on 20 November 2019, 20:48:13 UTC
Both rtl_work_func_t() and rtl8152_close() call napi_disable(). Since the two calls aren't protected by a lock, if the close function starts executing before the work function, we can get into a situation where the napi_disable() function is called twice in succession (first by rtl8152_close(), then by set_carrier()). In such a situation, the second call would loop indefinitely, since rtl8152_close() doesn't call napi_enable() to clear the NAPI_STATE_SCHED bit. The rtl8152_close() function in turn issues a cancel_delayed_work_sync(), and so it would wait indefinitely for the rtl_work_func_t() to complete. Since rtl8152_close() is called by a process holding rtnl_lock() which is requested by other processes, this eventually leads to a system deadlock and crash. Re-order the napi_disable() call to occur after the work function disabling and urb cancellation calls are issued. Change-Id: I6ef0b703fc214998a037a68f722f784e1d07815e Reported-by: http://crbug.com/1017928 Signed-off-by: Prashant Malani <pmalani@chromium.org> Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent b172845
compat.c
// SPDX-License-Identifier: GPL-2.0-only
/*
* linux/fs/compat.c
*
* Kernel compatibililty routines for e.g. 32 bit syscall support
* on 64 bit kernels.
*
* Copyright (C) 2002 Stephen Rothwell, IBM Corporation
* Copyright (C) 1997-2000 Jakub Jelinek (jakub@redhat.com)
* Copyright (C) 1998 Eddie C. Dost (ecd@skynet.be)
* Copyright (C) 2001,2002 Andi Kleen, SuSE Labs
* Copyright (C) 2003 Pavel Machek (pavel@ucw.cz)
*/
#include <linux/compat.h>
#include <linux/nfs4_mount.h>
#include <linux/syscalls.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include "internal.h"
struct compat_nfs_string {
compat_uint_t len;
compat_uptr_t data;
};
static inline void compat_nfs_string(struct nfs_string *dst,
struct compat_nfs_string *src)
{
dst->data = compat_ptr(src->data);
dst->len = src->len;
}
struct compat_nfs4_mount_data_v1 {
compat_int_t version;
compat_int_t flags;
compat_int_t rsize;
compat_int_t wsize;
compat_int_t timeo;
compat_int_t retrans;
compat_int_t acregmin;
compat_int_t acregmax;
compat_int_t acdirmin;
compat_int_t acdirmax;
struct compat_nfs_string client_addr;
struct compat_nfs_string mnt_path;
struct compat_nfs_string hostname;
compat_uint_t host_addrlen;
compat_uptr_t host_addr;
compat_int_t proto;
compat_int_t auth_flavourlen;
compat_uptr_t auth_flavours;
};
static int do_nfs4_super_data_conv(void *raw_data)
{
int version = *(compat_uint_t *) raw_data;
if (version == 1) {
struct compat_nfs4_mount_data_v1 *raw = raw_data;
struct nfs4_mount_data *real = raw_data;
/* copy the fields backwards */
real->auth_flavours = compat_ptr(raw->auth_flavours);
real->auth_flavourlen = raw->auth_flavourlen;
real->proto = raw->proto;
real->host_addr = compat_ptr(raw->host_addr);
real->host_addrlen = raw->host_addrlen;
compat_nfs_string(&real->hostname, &raw->hostname);
compat_nfs_string(&real->mnt_path, &raw->mnt_path);
compat_nfs_string(&real->client_addr, &raw->client_addr);
real->acdirmax = raw->acdirmax;
real->acdirmin = raw->acdirmin;
real->acregmax = raw->acregmax;
real->acregmin = raw->acregmin;
real->retrans = raw->retrans;
real->timeo = raw->timeo;
real->wsize = raw->wsize;
real->rsize = raw->rsize;
real->flags = raw->flags;
real->version = raw->version;
}
return 0;
}
#define NFS4_NAME "nfs4"
COMPAT_SYSCALL_DEFINE5(mount, const char __user *, dev_name,
const char __user *, dir_name,
const char __user *, type, compat_ulong_t, flags,
const void __user *, data)
{
char *kernel_type;
void *options;
char *kernel_dev;
int retval;
kernel_type = copy_mount_string(type);
retval = PTR_ERR(kernel_type);
if (IS_ERR(kernel_type))
goto out;
kernel_dev = copy_mount_string(dev_name);
retval = PTR_ERR(kernel_dev);
if (IS_ERR(kernel_dev))
goto out1;
options = copy_mount_options(data);
retval = PTR_ERR(options);
if (IS_ERR(options))
goto out2;
if (kernel_type && options) {
if (!strcmp(kernel_type, NFS4_NAME)) {
retval = -EINVAL;
if (do_nfs4_super_data_conv(options))
goto out3;
}
}
retval = do_mount(kernel_dev, dir_name, kernel_type, flags, options);
out3:
kfree(options);
out2:
kfree(kernel_dev);
out1:
kfree(kernel_type);
out:
return retval;
}
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