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authorAlexander Egorenkov <egorenar@linux.ibm.com>2024-05-10 11:39:53 +0200
committerAlexander Gordeev <agordeev@linux.ibm.com>2024-05-14 20:21:54 +0200
commit247576bf624a200b9d4dba6126e760af0d5ebe0e (patch)
tree548d474186879fd6dc3b278167c3a9841e892727 /arch/s390/kernel/ipl.c
parents390/ipl: Fix size of vmcmd buffers for sending z/VM CP diag X'008' cmds (diff)
downloadlinux-247576bf624a200b9d4dba6126e760af0d5ebe0e.tar.xz
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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/kernel/ipl.c')
-rw-r--r--arch/s390/kernel/ipl.c6
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; \
} \