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| author |  Alexander Egorenkov <egorenar@linux.ibm.com>
| 2024-05-10 11:39:53 +0200 |
|---|---|---|
| committer |  Alexander Gordeev <agordeev@linux.ibm.com>
| 2024-05-14 20:21:54 +0200 |
| commit | 247576bf624a200b9d4dba6126e760af0d5ebe0e (patch) | |
| tree | 548d474186879fd6dc3b278167c3a9841e892727 /arch/s390 | |
| parent | s390/ipl: Fix size of vmcmd buffers for sending z/VM CP diag X'008' cmds (diff) | |
| download | linux-247576bf624a200b9d4dba6126e760af0d5ebe0e.tar.gz linux-247576bf624a200b9d4dba6126e760af0d5ebe0e.tar.bz2 linux-247576bf624a200b9d4dba6126e760af0d5ebe0e.zip | |
s390/ipl: Do not accept z/VM CP diag X'008' cmds longer than max length
The old implementation of vmcmd sysfs string attributes truncated passed
z/VM CP diagnose X'008' commands which were longer than the max allowed
number of characters but the reported number of written characters was
still equal to the entire length of a given string. This can result in
silent failures of some s390-tools (e.g. dumpconf) which can be very hard
to detect. Therefore, this commit makes a write attempt to a vmcmd sysfs
attribute
* fail with E2BIG error if a given string is longer than the maximum
allowed one
* never destroy the old data in the vmcmd sysfs attribute if the new data
doesn't fit into it entirely
* return the actual number of written characters if it succeeds
Reviewed-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com>
Diffstat (limited to 'arch/s390')
| -rw-r--r-- | arch/s390/kernel/ipl.c | 6 |
1 files changed, 5 insertions, 1 deletions
diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c index eb3fd130ee81..f78c40e2b631 100644 --- a/arch/s390/kernel/ipl.c +++ b/arch/s390/kernel/ipl.c @@ -266,7 +266,11 @@ static ssize_t sys_##_prefix##_##_name##_store(struct kobject *kobj, \ struct kobj_attribute *attr, \ const char *buf, size_t len) \ { \ - strscpy(_value, buf, sizeof(_value)); \ + if (len >= sizeof(_value)) \ + return -E2BIG; \ + len = strscpy(_value, buf, sizeof(_value)); \ + if (len < 0) \ + return len; \ strim(_value); \ return len; \ } \ |