Commit-ID: 85c9306d44f757d2fb3b0e3e399080a025315c7f Gitweb: http://git.kernel.org/tip/85c9306d44f757d2fb3b0e3e399080a025315c7f Author: Aravind Gopalakrishnan <aravind.gopalakrish...@amd.com> AuthorDate: Mon, 12 Oct 2015 11:22:38 +0200 Committer: Ingo Molnar <mi...@kernel.org> CommitDate: Mon, 12 Oct 2015 16:15:47 +0200
x86/ras/mce_amd_inj: Return early on invalid input 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> Signed-off-by: Borislav Petkov <b...@suse.de> Cc: Borislav Petkov <b...@alien8.de> Cc: H. Peter Anvin <h...@zytor.com> Cc: Linus Torvalds <torva...@linux-foundation.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Thomas Gleixner <t...@linutronix.de> Cc: Tony Luck <tony.l...@intel.com> Link: http://lkml.kernel.org/r/1443190851-2172-2-git-send-email-aravind.gopalakrish...@amd.com Link: http://lkml.kernel.org/r/1444641762-9437-3-git-send-email...@alien8.de Signed-off-by: Ingo Molnar <mi...@kernel.org> --- 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 17e35b5..4fd8bb9 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 = { -- 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/
