diff options
| author | Luck, Tony <tony.luck@intel.com> | 2018-04-27 09:37:08 -0700 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-05-06 12:46:39 +0200 |
| commit | 985c78d3ff8e9c74450fa2bb08eb55e680d999ca (patch) | |
| tree | 7b186d3946c2a07045df8f7ed276eaeaaf24ad58 /arch/x86/kernel/cpu/mcheck/mce-inject.c | |
| parent | 13e8582245267b872dc6eb4ab695fffc797d99f5 (diff) | |
x86/MCE: Fix stack out-of-bounds write in mce-inject.c: Flags_read()
Each of the strings that we want to put into the buf[MAX_FLAG_OPT_SIZE]
in flags_read() is two characters long. But the sprintf() adds
a trailing newline and will add a terminating NUL byte. So
MAX_FLAG_OPT_SIZE needs to be 4.
sprintf() calls vsnprintf() and *that* does return:
" * The return value is the number of characters which would
* be generated for the given input, excluding the trailing
* '\0', as per ISO C99."
Note the "excluding".
Reported-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: stable@vger.kernel.org
Cc: linux-edac <linux-edac@vger.kernel.org>
Link: http://lkml.kernel.org/r/20180427163707.ktaiysvbk3yhk4wm@agluck-desk
Diffstat (limited to 'arch/x86/kernel/cpu/mcheck/mce-inject.c')
| -rw-r--r-- | arch/x86/kernel/cpu/mcheck/mce-inject.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/mcheck/mce-inject.c b/arch/x86/kernel/cpu/mcheck/mce-inject.c index 475cb4f5f14f..c805a06e14c3 100644 --- a/arch/x86/kernel/cpu/mcheck/mce-inject.c +++ b/arch/x86/kernel/cpu/mcheck/mce-inject.c @@ -48,7 +48,7 @@ static struct dentry *dfs_inj; static u8 n_banks; -#define MAX_FLAG_OPT_SIZE 3 +#define MAX_FLAG_OPT_SIZE 4 #define NBCFG 0x44 enum injection_type { |