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-rw-r--r--drivers/char/sysrq.c2
-rw-r--r--fs/cifs/cifsfs.c6
-rw-r--r--fs/cifs/dns_resolve.c69
-rw-r--r--fs/cifs/dns_resolve.h4
-rw-r--r--include/linux/sysrq.h1
-rw-r--r--kernel/debug/debug_core.c2
-rw-r--r--kernel/debug/gdbstub.c9
-rw-r--r--kernel/debug/kdb/kdb_main.c7
8 files changed, 85 insertions, 15 deletions
diff --git a/drivers/char/sysrq.c b/drivers/char/sysrq.c
index 5d64e3acb000..878ac0c2cc68 100644
--- a/drivers/char/sysrq.c
+++ b/drivers/char/sysrq.c
@@ -493,7 +493,7 @@ static void __sysrq_put_key_op(int key, struct sysrq_key_op *op_p)
sysrq_key_table[i] = op_p;
}
-static void __handle_sysrq(int key, struct tty_struct *tty, int check_mask)
+void __handle_sysrq(int key, struct tty_struct *tty, int check_mask)
{
struct sysrq_key_op *op_p;
int orig_log_level;
diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c
index 484e52bb40bb..2cb1a70214d7 100644
--- a/fs/cifs/cifsfs.c
+++ b/fs/cifs/cifsfs.c
@@ -923,7 +923,7 @@ init_cifs(void)
goto out_unregister_filesystem;
#endif
#ifdef CONFIG_CIFS_DFS_UPCALL
- rc = register_key_type(&key_type_dns_resolver);
+ rc = cifs_init_dns_resolver();
if (rc)
goto out_unregister_key_type;
#endif
@@ -935,7 +935,7 @@ init_cifs(void)
out_unregister_resolver_key:
#ifdef CONFIG_CIFS_DFS_UPCALL
- unregister_key_type(&key_type_dns_resolver);
+ cifs_exit_dns_resolver();
out_unregister_key_type:
#endif
#ifdef CONFIG_CIFS_UPCALL
@@ -961,7 +961,7 @@ exit_cifs(void)
cifs_proc_clean();
#ifdef CONFIG_CIFS_DFS_UPCALL
cifs_dfs_release_automount_timer();
- unregister_key_type(&key_type_dns_resolver);
+ cifs_exit_dns_resolver();
#endif
#ifdef CONFIG_CIFS_UPCALL
unregister_key_type(&cifs_spnego_key_type);
diff --git a/fs/cifs/dns_resolve.c b/fs/cifs/dns_resolve.c
index 4db2c5e7283f..49315cbf742d 100644
--- a/fs/cifs/dns_resolve.c
+++ b/fs/cifs/dns_resolve.c
@@ -24,12 +24,16 @@
*/
#include <linux/slab.h>
+#include <linux/keyctl.h>
+#include <linux/key-type.h>
#include <keys/user-type.h>
#include "dns_resolve.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_debug.h"
+static const struct cred *dns_resolver_cache;
+
/* Checks if supplied name is IP address
* returns:
* 1 - name is IP
@@ -94,6 +98,7 @@ struct key_type key_type_dns_resolver = {
int
dns_resolve_server_name_to_ip(const char *unc, char **ip_addr)
{
+ const struct cred *saved_cred;
int rc = -EAGAIN;
struct key *rkey = ERR_PTR(-EAGAIN);
char *name;
@@ -133,8 +138,15 @@ dns_resolve_server_name_to_ip(const char *unc, char **ip_addr)
goto skip_upcall;
}
+ saved_cred = override_creds(dns_resolver_cache);
rkey = request_key(&key_type_dns_resolver, name, "");
+ revert_creds(saved_cred);
if (!IS_ERR(rkey)) {
+ if (!(rkey->perm & KEY_USR_VIEW)) {
+ down_read(&rkey->sem);
+ rkey->perm |= KEY_USR_VIEW;
+ up_read(&rkey->sem);
+ }
len = rkey->type_data.x[0];
data = rkey->payload.data;
} else {
@@ -165,4 +177,61 @@ out:
return rc;
}
+int __init cifs_init_dns_resolver(void)
+{
+ struct cred *cred;
+ struct key *keyring;
+ int ret;
+
+ printk(KERN_NOTICE "Registering the %s key type\n",
+ key_type_dns_resolver.name);
+
+ /* create an override credential set with a special thread keyring in
+ * which DNS requests are cached
+ *
+ * this is used to prevent malicious redirections from being installed
+ * with add_key().
+ */
+ cred = prepare_kernel_cred(NULL);
+ if (!cred)
+ return -ENOMEM;
+
+ keyring = key_alloc(&key_type_keyring, ".dns_resolver", 0, 0, cred,
+ (KEY_POS_ALL & ~KEY_POS_SETATTR) |
+ KEY_USR_VIEW | KEY_USR_READ,
+ KEY_ALLOC_NOT_IN_QUOTA);
+ if (IS_ERR(keyring)) {
+ ret = PTR_ERR(keyring);
+ goto failed_put_cred;
+ }
+
+ ret = key_instantiate_and_link(keyring, NULL, 0, NULL, NULL);
+ if (ret < 0)
+ goto failed_put_key;
+
+ ret = register_key_type(&key_type_dns_resolver);
+ if (ret < 0)
+ goto failed_put_key;
+
+ /* instruct request_key() to use this special keyring as a cache for
+ * the results it looks up */
+ cred->thread_keyring = keyring;
+ cred->jit_keyring = KEY_REQKEY_DEFL_THREAD_KEYRING;
+ dns_resolver_cache = cred;
+ return 0;
+
+failed_put_key:
+ key_put(keyring);
+failed_put_cred:
+ put_cred(cred);
+ return ret;
+}
+void __exit cifs_exit_dns_resolver(void)
+{
+ key_revoke(dns_resolver_cache->thread_keyring);
+ unregister_key_type(&key_type_dns_resolver);
+ put_cred(dns_resolver_cache);
+ printk(KERN_NOTICE "Unregistered %s key type\n",
+ key_type_dns_resolver.name);
+}
diff --git a/fs/cifs/dns_resolve.h b/fs/cifs/dns_resolve.h
index 966e9288930b..26b9eaa9f5ee 100644
--- a/fs/cifs/dns_resolve.h
+++ b/fs/cifs/dns_resolve.h
@@ -24,8 +24,8 @@
#define _DNS_RESOLVE_H
#ifdef __KERNEL__
-#include <linux/key-type.h>
-extern struct key_type key_type_dns_resolver;
+extern int __init cifs_init_dns_resolver(void);
+extern void __exit cifs_exit_dns_resolver(void);
extern int dns_resolve_server_name_to_ip(const char *unc, char **ip_addr);
#endif /* KERNEL */
diff --git a/include/linux/sysrq.h b/include/linux/sysrq.h
index 4496322e28dd..609e8ca5f534 100644
--- a/include/linux/sysrq.h
+++ b/include/linux/sysrq.h
@@ -45,6 +45,7 @@ struct sysrq_key_op {
*/
void handle_sysrq(int key, struct tty_struct *tty);
+void __handle_sysrq(int key, struct tty_struct *tty, int check_mask);
int register_sysrq_key(int key, struct sysrq_key_op *op);
int unregister_sysrq_key(int key, struct sysrq_key_op *op);
struct sysrq_key_op *__sysrq_get_key_op(int key);
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 5cb7cd1de10c..8bc5eeffec8a 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -605,13 +605,13 @@ cpu_master_loop:
if (dbg_kdb_mode) {
kgdb_connected = 1;
error = kdb_stub(ks);
+ kgdb_connected = 0;
} else {
error = gdb_serial_stub(ks);
}
if (error == DBG_PASS_EVENT) {
dbg_kdb_mode = !dbg_kdb_mode;
- kgdb_connected = 0;
} else if (error == DBG_SWITCH_CPU_EVENT) {
dbg_cpu_switch(cpu, dbg_switch_cpu);
goto cpu_loop;
diff --git a/kernel/debug/gdbstub.c b/kernel/debug/gdbstub.c
index 4b17b3269525..e8fd6868682d 100644
--- a/kernel/debug/gdbstub.c
+++ b/kernel/debug/gdbstub.c
@@ -621,10 +621,8 @@ static void gdb_cmd_query(struct kgdb_state *ks)
switch (remcom_in_buffer[1]) {
case 's':
case 'f':
- if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10)) {
- error_packet(remcom_out_buffer, -EINVAL);
+ if (memcmp(remcom_in_buffer + 2, "ThreadInfo", 10))
break;
- }
i = 0;
remcom_out_buffer[0] = 'm';
@@ -665,10 +663,9 @@ static void gdb_cmd_query(struct kgdb_state *ks)
pack_threadid(remcom_out_buffer + 2, thref);
break;
case 'T':
- if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16)) {
- error_packet(remcom_out_buffer, -EINVAL);
+ if (memcmp(remcom_in_buffer + 1, "ThreadExtraInfo,", 16))
break;
- }
+
ks->threadid = 0;
ptr = remcom_in_buffer + 17;
kgdb_hex2long(&ptr, &ks->threadid);
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 184cd8209c36..ebe4a287419e 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -1820,9 +1820,8 @@ static int kdb_sr(int argc, const char **argv)
{
if (argc != 1)
return KDB_ARGCOUNT;
- sysrq_toggle_support(1);
kdb_trap_printk++;
- handle_sysrq(*argv[1], NULL);
+ __handle_sysrq(*argv[1], NULL, 0);
kdb_trap_printk--;
return 0;
@@ -1883,6 +1882,7 @@ static int kdb_lsmod(int argc, const char **argv)
kdb_printf(" (Loading)");
else
kdb_printf(" (Live)");
+ kdb_printf(" 0x%p", mod->module_core);
#ifdef CONFIG_MODULE_UNLOAD
{
@@ -2291,6 +2291,9 @@ static int kdb_ll(int argc, const char **argv)
while (va) {
char buf[80];
+ if (KDB_FLAG(CMD_INTERRUPT))
+ return 0;
+
sprintf(buf, "%s " kdb_machreg_fmt "\n", command, va);
diag = kdb_parse(buf);
if (diag)
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