forked from luck/tmp_suning_uos_patched
ce9d9b8e5c
the returned buffer of register_sysctl() is stored into net_header variable, but net_header is not used after, and compiler maybe optimise the variable out, and lead kmemleak reported the below warning comm "swapper/0", pid 1, jiffies 4294937448 (age 267.270s) hex dump (first 32 bytes): 90 38 8b 01 c0 ff ff ff 00 00 00 00 01 00 00 00 .8.............. 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffc00020f134>] create_object+0x10c/0x2a0 [<ffffffc00070ff44>] kmemleak_alloc+0x54/0xa0 [<ffffffc0001fe378>] __kmalloc+0x1f8/0x4f8 [<ffffffc00028e984>] __register_sysctl_table+0x64/0x5a0 [<ffffffc00028eef0>] register_sysctl+0x30/0x40 [<ffffffc00099c304>] net_sysctl_init+0x20/0x58 [<ffffffc000994dd8>] sock_init+0x10/0xb0 [<ffffffc0000842e0>] do_one_initcall+0x90/0x1b8 [<ffffffc000966bac>] kernel_init_freeable+0x218/0x2f0 [<ffffffc00070ed6c>] kernel_init+0x1c/0xe8 [<ffffffc000083bfc>] ret_from_fork+0xc/0x50 [<ffffffffffffffff>] 0xffffffffffffffff <<end check kmemleak>> Before fix, the objdump result on ARM64: 0000000000000000 <net_sysctl_init>: 0: a9be7bfd stp x29, x30, [sp,#-32]! 4: 90000001 adrp x1, 0 <net_sysctl_init> 8: 90000000 adrp x0, 0 <net_sysctl_init> c: 910003fd mov x29, sp 10: 91000021 add x1, x1, #0x0 14: 91000000 add x0, x0, #0x0 18: a90153f3 stp x19, x20, [sp,#16] 1c: 12800174 mov w20, #0xfffffff4 // #-12 20: 94000000 bl 0 <register_sysctl> 24: b4000120 cbz x0, 48 <net_sysctl_init+0x48> 28: 90000013 adrp x19, 0 <net_sysctl_init> 2c: 91000273 add x19, x19, #0x0 30: 9101a260 add x0, x19, #0x68 34: 94000000 bl 0 <register_pernet_subsys> 38: 2a0003f4 mov w20, w0 3c: 35000060 cbnz w0, 48 <net_sysctl_init+0x48> 40: aa1303e0 mov x0, x19 44: 94000000 bl 0 <register_sysctl_root> 48: 2a1403e0 mov w0, w20 4c: a94153f3 ldp x19, x20, [sp,#16] 50: a8c27bfd ldp x29, x30, [sp],#32 54: d65f03c0 ret After: 0000000000000000 <net_sysctl_init>: 0: a9bd7bfd stp x29, x30, [sp,#-48]! 4: 90000000 adrp x0, 0 <net_sysctl_init> 8: 910003fd mov x29, sp c: a90153f3 stp x19, x20, [sp,#16] 10: 90000013 adrp x19, 0 <net_sysctl_init> 14: 91000000 add x0, x0, #0x0 18: 91000273 add x19, x19, #0x0 1c: f90013f5 str x21, [sp,#32] 20: aa1303e1 mov x1, x19 24: 12800175 mov w21, #0xfffffff4 // #-12 28: 94000000 bl 0 <register_sysctl> 2c: f9002260 str x0, [x19,#64] 30: b40001a0 cbz x0, 64 <net_sysctl_init+0x64> 34: 90000014 adrp x20, 0 <net_sysctl_init> 38: 91000294 add x20, x20, #0x0 3c: 9101a280 add x0, x20, #0x68 40: 94000000 bl 0 <register_pernet_subsys> 44: 2a0003f5 mov w21, w0 48: 35000080 cbnz w0, 58 <net_sysctl_init+0x58> 4c: aa1403e0 mov x0, x20 50: 94000000 bl 0 <register_sysctl_root> 54: 14000004 b 64 <net_sysctl_init+0x64> 58: f9402260 ldr x0, [x19,#64] 5c: 94000000 bl 0 <unregister_sysctl_table> 60: f900227f str xzr, [x19,#64] 64: 2a1503e0 mov w0, w21 68: f94013f5 ldr x21, [sp,#32] 6c: a94153f3 ldp x19, x20, [sp,#16] 70: a8c37bfd ldp x29, x30, [sp],#48 74: d65f03c0 ret Add the possible error handle to free the net_header to remove the kmemleak warning Signed-off-by: Li RongQing <roy.qing.li@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
119 lines
2.9 KiB
C
119 lines
2.9 KiB
C
/* -*- linux-c -*-
|
|
* sysctl_net.c: sysctl interface to net subsystem.
|
|
*
|
|
* Begun April 1, 1996, Mike Shaver.
|
|
* Added /proc/sys/net directories for each protocol family. [MS]
|
|
*
|
|
* Revision 1.2 1996/05/08 20:24:40 shaver
|
|
* Added bits for NET_BRIDGE and the NET_IPV4_ARP stuff and
|
|
* NET_IPV4_IP_FORWARD.
|
|
*
|
|
*
|
|
*/
|
|
|
|
#include <linux/mm.h>
|
|
#include <linux/export.h>
|
|
#include <linux/sysctl.h>
|
|
#include <linux/nsproxy.h>
|
|
|
|
#include <net/sock.h>
|
|
|
|
#ifdef CONFIG_INET
|
|
#include <net/ip.h>
|
|
#endif
|
|
|
|
#ifdef CONFIG_NET
|
|
#include <linux/if_ether.h>
|
|
#endif
|
|
|
|
static struct ctl_table_set *
|
|
net_ctl_header_lookup(struct ctl_table_root *root, struct nsproxy *namespaces)
|
|
{
|
|
return &namespaces->net_ns->sysctls;
|
|
}
|
|
|
|
static int is_seen(struct ctl_table_set *set)
|
|
{
|
|
return ¤t->nsproxy->net_ns->sysctls == set;
|
|
}
|
|
|
|
/* Return standard mode bits for table entry. */
|
|
static int net_ctl_permissions(struct ctl_table_header *head,
|
|
struct ctl_table *table)
|
|
{
|
|
struct net *net = container_of(head->set, struct net, sysctls);
|
|
kuid_t root_uid = make_kuid(net->user_ns, 0);
|
|
kgid_t root_gid = make_kgid(net->user_ns, 0);
|
|
|
|
/* Allow network administrator to have same access as root. */
|
|
if (ns_capable(net->user_ns, CAP_NET_ADMIN) ||
|
|
uid_eq(root_uid, current_euid())) {
|
|
int mode = (table->mode >> 6) & 7;
|
|
return (mode << 6) | (mode << 3) | mode;
|
|
}
|
|
/* Allow netns root group to have the same access as the root group */
|
|
if (in_egroup_p(root_gid)) {
|
|
int mode = (table->mode >> 3) & 7;
|
|
return (mode << 3) | mode;
|
|
}
|
|
return table->mode;
|
|
}
|
|
|
|
static struct ctl_table_root net_sysctl_root = {
|
|
.lookup = net_ctl_header_lookup,
|
|
.permissions = net_ctl_permissions,
|
|
};
|
|
|
|
static int __net_init sysctl_net_init(struct net *net)
|
|
{
|
|
setup_sysctl_set(&net->sysctls, &net_sysctl_root, is_seen);
|
|
return 0;
|
|
}
|
|
|
|
static void __net_exit sysctl_net_exit(struct net *net)
|
|
{
|
|
retire_sysctl_set(&net->sysctls);
|
|
}
|
|
|
|
static struct pernet_operations sysctl_pernet_ops = {
|
|
.init = sysctl_net_init,
|
|
.exit = sysctl_net_exit,
|
|
};
|
|
|
|
static struct ctl_table_header *net_header;
|
|
__init int net_sysctl_init(void)
|
|
{
|
|
static struct ctl_table empty[1];
|
|
int ret = -ENOMEM;
|
|
/* Avoid limitations in the sysctl implementation by
|
|
* registering "/proc/sys/net" as an empty directory not in a
|
|
* network namespace.
|
|
*/
|
|
net_header = register_sysctl("net", empty);
|
|
if (!net_header)
|
|
goto out;
|
|
ret = register_pernet_subsys(&sysctl_pernet_ops);
|
|
if (ret)
|
|
goto out1;
|
|
register_sysctl_root(&net_sysctl_root);
|
|
out:
|
|
return ret;
|
|
out1:
|
|
unregister_sysctl_table(net_header);
|
|
net_header = NULL;
|
|
goto out;
|
|
}
|
|
|
|
struct ctl_table_header *register_net_sysctl(struct net *net,
|
|
const char *path, struct ctl_table *table)
|
|
{
|
|
return __register_sysctl_table(&net->sysctls, path, table);
|
|
}
|
|
EXPORT_SYMBOL_GPL(register_net_sysctl);
|
|
|
|
void unregister_net_sysctl_table(struct ctl_table_header *header)
|
|
{
|
|
unregister_sysctl_table(header);
|
|
}
|
|
EXPORT_SYMBOL_GPL(unregister_net_sysctl_table);
|