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vsprintf: Shuffle restricted_pointer() 

This is just a preparation step for further changes.

The patch does not change the code.

Link: http://lkml.kernel.org/r/20190417115350.20479-2-pmladek@suse.com
To: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: "Tobin C . Harding" <me@tobin.cc>
Cc: Joe Perches <joe@perches.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: linux-kernel@vger.kernel.org
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
This commit is contained in:
Petr Mladek 2019-04-17 13:53:41 +02:00
parent c4703acd6d
commit 6eea242f9b
1 changed files with 49 additions and 49 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

98
lib/vsprintf.c
View File

@ -717,6 +717,55 @@ static char *ptr_to_id(char *buf, char *end, const void *ptr,
return pointer_string(buf, end, (const void *)hashval, spec);
}
int kptr_restrict __read_mostly;
static noinline_for_stack
char *restricted_pointer(char *buf, char *end, const void *ptr,
struct printf_spec spec)
{
switch (kptr_restrict) {
case 0:
/* Always print %pK values */
break;
case 1: {
const struct cred *cred;
/*
* kptr_restrict==1 cannot be used in IRQ context
* because its test for CAP_SYSLOG would be meaningless.
*/
if (in_irq() || in_serving_softirq() || in_nmi()) {
if (spec.field_width == -1)
spec.field_width = 2 * sizeof(ptr);
return string(buf, end, "pK-error", spec);
}
/*
* Only print the real pointer value if the current
* process has CAP_SYSLOG and is running with the
* same credentials it started with. This is because
* access to files is checked at open() time, but %pK
* checks permission at read() time. We don't want to
* leak pointer values if a binary opens a file using
* %pK and then elevates privileges before reading it.
*/
cred = current_cred();
if (!has_capability_noaudit(current, CAP_SYSLOG) ||
!uid_eq(cred->euid, cred->uid) ||
!gid_eq(cred->egid, cred->gid))
ptr = NULL;
break;
}
case 2:
default:
/* Always print 0's for %pK */
ptr = NULL;
break;
}
return pointer_string(buf, end, ptr, spec);
}
static noinline_for_stack
char *dentry_name(char *buf, char *end, const struct dentry *d, struct printf_spec spec,
const char *fmt)
@ -1476,55 +1525,6 @@ char *uuid_string(char *buf, char *end, const u8 *addr,
return string(buf, end, uuid, spec);
}
int kptr_restrict __read_mostly;
static noinline_for_stack
char *restricted_pointer(char *buf, char *end, const void *ptr,
struct printf_spec spec)
{
switch (kptr_restrict) {
case 0:
/* Always print %pK values */
break;
case 1: {
const struct cred *cred;
/*
* kptr_restrict==1 cannot be used in IRQ context
* because its test for CAP_SYSLOG would be meaningless.
*/
if (in_irq() || in_serving_softirq() || in_nmi()) {
if (spec.field_width == -1)
spec.field_width = 2 * sizeof(ptr);
return string(buf, end, "pK-error", spec);
}
/*
* Only print the real pointer value if the current
* process has CAP_SYSLOG and is running with the
* same credentials it started with. This is because
* access to files is checked at open() time, but %pK
* checks permission at read() time. We don't want to
* leak pointer values if a binary opens a file using
* %pK and then elevates privileges before reading it.
*/
cred = current_cred();
if (!has_capability_noaudit(current, CAP_SYSLOG) ||
!uid_eq(cred->euid, cred->uid) ||
!gid_eq(cred->egid, cred->gid))
ptr = NULL;
break;
}
case 2:
default:
/* Always print 0's for %pK */
ptr = NULL;
break;
}
return pointer_string(buf, end, ptr, spec);
}
static noinline_for_stack
char *netdev_bits(char *buf, char *end, const void *addr,
struct printf_spec spec, const char *fmt)