Merge branch 'akpm' (patches from Andrew Morton)

Merge first patch-bomb from Andrew Morton:
 "Quite a lot of other stuff is banked up awaiting further
  next->mainline merging, but this batch contains:

   - Lots of random misc patches
   - OCFS2
   - Most of MM
   - backlight updates
   - lib/ updates
   - printk updates
   - checkpatch updates
   - epoll tweaking
   - rtc updates
   - hfs
   - hfsplus
   - documentation
   - procfs
   - update gcov to gcc-4.7 format
   - IPC"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (269 commits)
  ipc, msg: fix message length check for negative values
  ipc/util.c: remove unnecessary work pending test
  devpts: plug the memory leak in kill_sb
  ./Makefile: export initial ramdisk compression config option
  init/Kconfig: add option to disable kernel compression
  drivers: w1: make w1_slave::flags long to avoid memory corruption
  drivers/w1/masters/ds1wm.cuse dev_get_platdata()
  drivers/memstick/core/ms_block.c: fix unreachable state in h_msb_read_page()
  drivers/memstick/core/mspro_block.c: fix attributes array allocation
  drivers/pps/clients/pps-gpio.c: remove redundant of_match_ptr
  kernel/panic.c: reduce 1 byte usage for print tainted buffer
  gcov: reuse kbasename helper
  kernel/gcov/fs.c: use pr_warn()
  kernel/module.c: use pr_foo()
  gcov: compile specific gcov implementation based on gcc version
  gcov: add support for gcc 4.7 gcov format
  gcov: move gcov structs definitions to a gcc version specific file
  kernel/taskstats.c: return -ENOMEM when alloc memory fails in add_del_listener()
  kernel/taskstats.c: add nla_nest_cancel() for failure processing between nla_nest_start() and nla_nest_end()
  kernel/sysctl_binary.c: use scnprintf() instead of snprintf()
  ...

1 files changed, 32 insertions, 3 deletions

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index 26559bdb4c49..48586ac3a62e 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -27,6 +27,7 @@
 #include <linux/uaccess.h>
 #include <linux/ioport.h>
 #include <linux/dcache.h>
+#include <linux/cred.h>
 #include <net/addrconf.h>
 
 #include <asm/page.h>		/* for PAGE_SIZE */
@@ -1218,6 +1219,8 @@ int kptr_restrict __read_mostly;
  *            The maximum supported length is 64 bytes of the input. Consider
  *            to use print_hex_dump() for the larger input.
  * - 'a' For a phys_addr_t type and its derivative types (passed by reference)
+ * - 'd[234]' For a dentry name (optionally 2-4 last components)
+ * - 'D[234]' Same as 'd' but for a struct file
  *
  * Note: The difference between 'S' and 'F' is that on ia64 and ppc64
  * function pointers are really function descriptors, which contain a
@@ -1312,11 +1315,37 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr,
 				spec.field_width = default_width;
 			return string(buf, end, "pK-error", spec);
 		}
-		if (!((kptr_restrict == 0) ||
-		      (kptr_restrict == 1 &&
-		       has_capability_noaudit(current, CAP_SYSLOG))))
+
+		switch (kptr_restrict) {
+		case 0:
+			/* Always print %pK values */
+			break;
+		case 1: {
+			/*
+			 * 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.
+			 */
+			const struct cred *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;
+		}
 		break;
+
 	case 'N':
 		switch (fmt[1]) {
 		case 'F':