From: Aravind Gopalakrishnan <aravind.gopalakrish...@amd.com> Invalid inputs such as these are currently reported in dmesg as failing:
$> echo sweet > flags [ 122.079139] flags_write: Invalid flags value: et even though the 'flags' attribute has been updated correctly: $> cat flags sw This is because userspace keeps writing the remaining buffer until it encounters an error. However, the input as a whole is wrong and we should not be writing anything to the file. Therefore, correct flags_write() to return -EINVAL immediately on bad input strings. Signed-off-by: Aravind Gopalakrishnan <aravind.gopalakrish...@amd.com> Cc: "H. Peter Anvin" <h...@zytor.com> Cc: Ingo Molnar <mi...@redhat.com> Cc: Thomas Gleixner <t...@linutronix.de> Cc: x86-ml <x...@kernel.org> Link: http://lkml.kernel.org/r/1443190851-2172-2-git-send-email-aravind.gopalakrish...@amd.com Signed-off-by: Borislav Petkov <b...@suse.de> --- arch/x86/ras/mce_amd_inj.c | 9 +++------ 1 file changed, 3 insertions(+), 6 deletions(-) diff --git a/arch/x86/ras/mce_amd_inj.c b/arch/x86/ras/mce_amd_inj.c index 17e35b5bf779..4fd8bb9b90b9 100644 --- a/arch/x86/ras/mce_amd_inj.c +++ b/arch/x86/ras/mce_amd_inj.c @@ -129,12 +129,9 @@ static ssize_t flags_write(struct file *filp, const char __user *ubuf, { char buf[MAX_FLAG_OPT_SIZE], *__buf; int err; - size_t ret; if (cnt > MAX_FLAG_OPT_SIZE) - cnt = MAX_FLAG_OPT_SIZE; - - ret = cnt; + return -EINVAL; if (copy_from_user(&buf, ubuf, cnt)) return -EFAULT; @@ -150,9 +147,9 @@ static ssize_t flags_write(struct file *filp, const char __user *ubuf, return err; } - *ppos += ret; + *ppos += cnt; - return ret; + return cnt; } static const struct file_operations flags_fops = { -- 2.3.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
