From: Petr Mladek <pmladek@suse.com>
To: Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
"Tobin C . Harding" <me@tobin.cc>, Joe Perches <joe@perches.com>,
Andrew Morton <akpm@linux-foundation.org>,
Michal Hocko <mhocko@suse.cz>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Steven Rostedt <rostedt@goodmis.org>,
Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
linux-kernel@vger.kernel.org, Petr Mladek <pmladek@suse.com>
Subject: [PATCH v7 01/10] vsprintf: Shuffle restricted_pointer()
Date: Wed, 17 Apr 2019 13:53:41 +0200 [thread overview]
Message-ID: <20190417115350.20479-2-pmladek@suse.com> (raw)
In-Reply-To: <20190417115350.20479-1-pmladek@suse.com>
This is just a preparation step for further changes.
The patch does not change the code.
Signed-off-by: Petr Mladek <pmladek@suse.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
lib/vsprintf.c | 98 +++++++++++++++++++++++++++++-----------------------------
1 file changed, 49 insertions(+), 49 deletions(-)
diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 791b6fa36905..eb7b4a06e1f0 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -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)
--
2.16.4
next prev parent reply other threads:[~2019-04-17 11:54 UTC|newest]
Thread overview: 22+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-17 11:53 [PATCH v7 00/10] vsprintf: Prevent silent crashes and consolidate error handling Petr Mladek
2019-04-17 11:53 ` Petr Mladek [this message]
2019-04-17 11:53 ` [PATCH v7 02/10] vsprintf: Consistent %pK handling for kptr_restrict == 0 Petr Mladek
2019-04-17 13:44 ` Steven Rostedt
2019-04-17 11:53 ` [PATCH v7 03/10] vsprintf: Do not check address of well-known strings Petr Mladek
2019-04-17 11:53 ` [PATCH v7 04/10] vsprintf: Factor out %p[iI] handler as ip_addr_string() Petr Mladek
2019-04-17 11:53 ` [PATCH v7 05/10] vsprintf: Factor out %pV handler as va_format() Petr Mladek
2019-04-17 11:53 ` [PATCH v7 06/10] vsprintf: Factor out %pO handler as kobject_string() Petr Mladek
2019-04-17 11:53 ` [PATCH v7 07/10] vsprintf: Consolidate handling of unknown pointer specifiers Petr Mladek
2019-04-18 14:34 ` Sergey Senozhatsky
2019-04-18 14:43 ` Sergey Senozhatsky
2019-04-18 14:50 ` Sergey Senozhatsky
2019-06-25 10:59 ` Geert Uytterhoeven
2019-06-26 10:46 ` Petr Mladek
2019-06-26 11:16 ` Geert Uytterhoeven
2019-04-17 11:53 ` [PATCH v7 08/10] vsprintf: Prevent crash when dereferencing invalid pointers Petr Mladek
2019-04-17 11:53 ` [PATCH v7 09/10] vsprintf: Avoid confusion between invalid address and value Petr Mladek
2019-04-17 11:53 ` [PATCH v7 10/10] vsprintf: Limit the length of inlined error messages Petr Mladek
2019-04-19 1:51 ` [PATCH v7 00/10] vsprintf: Prevent silent crashes and consolidate error handling Sergey Senozhatsky
2019-04-24 13:53 ` Petr Mladek
2019-04-26 13:02 ` Andy Shevchenko
2019-04-26 14:27 ` Petr Mladek
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