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| author | Aravind Gopalakrishnan <Aravind.Gopalakrishnan@amd.com> | 2015-10-12 11:22:38 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-10-12 16:15:47 +0200 |
| commit | 85c9306d44f757d2fb3b0e3e399080a025315c7f (patch) | |
| tree | f3739ff23a559c7370e6a578edbde3daad2e3c5a /arch/x86/ras | |
| parent | cdbcd239e2e264dc3ef7bc7865bcb8ec0023876f (diff) | |
| download | linux-stable-85c9306d44f757d2fb3b0e3e399080a025315c7f.tar.gz linux-stable-85c9306d44f757d2fb3b0e3e399080a025315c7f.tar.bz2 linux-stable-85c9306d44f757d2fb3b0e3e399080a025315c7f.zip | |
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.Gopalakrishnan@amd.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/1443190851-2172-2-git-send-email-Aravind.Gopalakrishnan@amd.com
Link: http://lkml.kernel.org/r/1444641762-9437-3-git-send-email-bp@alien8.de
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/ras')
| -rw-r--r-- | arch/x86/ras/mce_amd_inj.c | 9 |
1 files 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 = { |