diff options
| author | Geert Uytterhoeven <geert+renesas@glider.be> | 2018-10-11 10:42:49 +0200 |
|---|---|---|
| committer | Petr Mladek <pmladek@suse.com> | 2018-10-12 11:26:55 +0200 |
| commit | 431bca24308c5a82575571023a7128a881f716b2 (patch) | |
| tree | d6292005fad5736aac758907ae6b1f8370b95efb | |
| parent | ec12bc2909f9759747ab5ad3709472353c43a750 (diff) | |
| download | linux-431bca24308c5a82575571023a7128a881f716b2.tar.gz linux-431bca24308c5a82575571023a7128a881f716b2.tar.bz2 linux-431bca24308c5a82575571023a7128a881f716b2.zip | |
lib/vsprintf: Hash printed address for netdev bits fallback
The handler for "%pN" falls back to printing the raw pointer value when
using a different format than the (sole supported) special format
"%pNF", potentially leaking sensitive information regarding the kernel
layout in memory.
Avoid this leak by printing the hashed address instead.
Note that there are no in-tree users of the fallback.
Fixes: ad67b74d2469d9b8 ("printk: hash addresses printed with %p")
Link: http://lkml.kernel.org/r/20181011084249.4520-4-geert+renesas@glider.be
To: "Tobin C . Harding" <me@tobin.cc>
To: Andrew Morton <akpm@linux-foundation.org>
To: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Petr Mladek <pmladek@suse.com>
| -rw-r--r-- | lib/vsprintf.c | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/lib/vsprintf.c b/lib/vsprintf.c index fee87b038ead..a5da653e00e7 100644 --- a/lib/vsprintf.c +++ b/lib/vsprintf.c @@ -1510,7 +1510,8 @@ char *restricted_pointer(char *buf, char *end, const void *ptr, } static noinline_for_stack -char *netdev_bits(char *buf, char *end, const void *addr, const char *fmt) +char *netdev_bits(char *buf, char *end, const void *addr, + struct printf_spec spec, const char *fmt) { unsigned long long num; int size; @@ -1521,9 +1522,7 @@ char *netdev_bits(char *buf, char *end, const void *addr, const char *fmt) size = sizeof(netdev_features_t); break; default: - num = (unsigned long)addr; - size = sizeof(unsigned long); - break; + return ptr_to_id(buf, end, addr, spec); } return special_hex_number(buf, end, num, size); @@ -1945,7 +1944,7 @@ char *pointer(const char *fmt, char *buf, char *end, void *ptr, break; return restricted_pointer(buf, end, ptr, spec); case 'N': - return netdev_bits(buf, end, ptr, fmt); + return netdev_bits(buf, end, ptr, spec, fmt); case 'a': return address_val(buf, end, ptr, fmt); case 'd': |