Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
capabilities/syslog: open code cap_syslog logic to fix build failure
The addition of CONFIG_SECURITY_DMESG_RESTRICT resulted in a build
failure when CONFIG_PRINTK=n. This is because the capabilities code
which used the new option was built even though the variable in question
didn't exist.
The patch here fixes this by moving the capabilities checks out of the
LSM and into the caller. All (known) LSMs should have been calling the
capabilities hook already so it actually makes the code organization
better to eliminate the hook altogether.
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
authored by
Eric Paris
and committed by
Linus Torvalds
12b3052c
6800e4c0
+28
-40
+4
-5
include/linux/security.h
+4
-5
include/linux/security.h
···
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77
extern int cap_task_setscheduler(struct task_struct *p);
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extern int cap_task_setioprio(struct task_struct *p, int ioprio);
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extern int cap_task_setnice(struct task_struct *p, int nice);
80
-
extern int cap_syslog(int type, bool from_file);
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extern int cap_vm_enough_memory(struct mm_struct *mm, long pages);
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struct msghdr;
···
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1388
int (*sysctl) (struct ctl_table *table, int op);
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int (*quotactl) (int cmds, int type, int id, struct super_block *sb);
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int (*quota_on) (struct dentry *dentry);
1390
-
int (*syslog) (int type, bool from_file);
1391
+
int (*syslog) (int type);
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int (*settime) (struct timespec *ts, struct timezone *tz);
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int (*vm_enough_memory) (struct mm_struct *mm, long pages);
1393
1394
···
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int security_sysctl(struct ctl_table *table, int op);
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int security_quotactl(int cmds, int type, int id, struct super_block *sb);
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int security_quota_on(struct dentry *dentry);
1673
-
int security_syslog(int type, bool from_file);
1674
+
int security_syslog(int type);
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int security_settime(struct timespec *ts, struct timezone *tz);
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int security_vm_enough_memory(long pages);
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int security_vm_enough_memory_mm(struct mm_struct *mm, long pages);
···
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return 0;
1901
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}
1902
1903
1903
-
static inline int security_syslog(int type, bool from_file)
1904
+
static inline int security_syslog(int type)
1904
1905
{
1905
-
return cap_syslog(type, from_file);
1906
+
return 0;
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}
1907
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static inline int security_settime(struct timespec *ts, struct timezone *tz)
+14
-1
kernel/printk.c
+14
-1
kernel/printk.c
···
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char c;
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int error = 0;
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-
error = security_syslog(type, from_file);
277
+
/*
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+
* If this is from /proc/kmsg we only do the capabilities checks
279
+
* at open time.
280
+
*/
281
+
if (type == SYSLOG_ACTION_OPEN || !from_file) {
282
+
if (dmesg_restrict && !capable(CAP_SYS_ADMIN))
283
+
return -EPERM;
284
+
if ((type != SYSLOG_ACTION_READ_ALL &&
285
+
type != SYSLOG_ACTION_SIZE_BUFFER) &&
286
+
!capable(CAP_SYS_ADMIN))
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+
return -EPERM;
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+
}
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+
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+
error = security_syslog(type);
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if (error)
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return error;
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+5
security/capability.c
+5
security/capability.c
-21
security/commoncap.c
-21
security/commoncap.c
···
27
27
#include <linux/sched.h>
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28
#include <linux/prctl.h>
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#include <linux/securebits.h>
30
-
#include <linux/syslog.h>
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/*
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* If a non-root user executes a setuid-root binary in
···
880
881
error:
881
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abort_creds(new);
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return error;
883
-
}
884
-
885
-
/**
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-
* cap_syslog - Determine whether syslog function is permitted
887
-
* @type: Function requested
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-
* @from_file: Whether this request came from an open file (i.e. /proc)
889
-
*
890
-
* Determine whether the current process is permitted to use a particular
891
-
* syslog function, returning 0 if permission is granted, -ve if not.
892
-
*/
893
-
int cap_syslog(int type, bool from_file)
894
-
{
895
-
if (type != SYSLOG_ACTION_OPEN && from_file)
896
-
return 0;
897
-
if (dmesg_restrict && !capable(CAP_SYS_ADMIN))
898
-
return -EPERM;
899
-
if ((type != SYSLOG_ACTION_READ_ALL &&
900
-
type != SYSLOG_ACTION_SIZE_BUFFER) && !capable(CAP_SYS_ADMIN))
901
-
return -EPERM;
902
-
return 0;
903
884
}
904
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905
886
/**
+2
-2
security/security.c
+2
-2
security/security.c
···
197
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return security_ops->quota_on(dentry);
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}
199
199
200
-
int security_syslog(int type, bool from_file)
200
+
int security_syslog(int type)
201
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{
202
-
return security_ops->syslog(type, from_file);
202
+
return security_ops->syslog(type);
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}
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int security_settime(struct timespec *ts, struct timezone *tz)
+1
-5
security/selinux/hooks.c
+1
-5
security/selinux/hooks.c
···
1973
1973
return dentry_has_perm(cred, NULL, dentry, FILE__QUOTAON);
1974
1974
}
1975
1975
1976
-
static int selinux_syslog(int type, bool from_file)
1976
+
static int selinux_syslog(int type)
1977
1977
{
1978
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int rc;
1979
-
1980
-
rc = cap_syslog(type, from_file);
1981
-
if (rc)
1982
-
return rc;
1983
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switch (type) {
1985
1981
case SYSLOG_ACTION_READ_ALL: /* Read last kernel messages */
+2
-6
security/smack/smack_lsm.c
+2
-6
security/smack/smack_lsm.c
···
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*
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* Returns 0 on success, error code otherwise.
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*/
160
-
static int smack_syslog(int type, bool from_file)
160
+
static int smack_syslog(int typefrom_file)
161
161
{
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-
int rc;
162
+
int rc = 0;
163
163
char *sp = current_security();
164
-
165
-
rc = cap_syslog(type, from_file);
166
-
if (rc != 0)
167
-
return rc;
168
164
169
165
if (capable(CAP_MAC_OVERRIDE))
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return 0;