There are multiple errors in how sys_32_personality() handles personality
flags stored in top three bytes.
- directly comparing current->personality against PER_LINUX32 doesn't work
in cases when any of the personality flags stored in the top three bytes
are used.
- directly forcefully setting personality to PER_LINUX32 or PER_LINUX
discards any flags stored in the top three bytes
Fix the first one by properly using personality() macro to compare only
bytes covered by PER_MASK.
Fix the second one by setting only the bits that should be set, instead of
overwriting the whole value.
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
---
arch/s390/kernel/sys_s390.c | 9 +++++----
1 files changed, 5 insertions(+), 4 deletions(-)
diff --git a/arch/s390/kernel/sys_s390.c b/arch/s390/kernel/sys_s390.c
index b4a29ee..6afcfd9 100644
--- a/arch/s390/kernel/sys_s390.c
+++ b/arch/s390/kernel/sys_s390.c
@@ -81,11 +81,12 @@ SYSCALL_DEFINE1(s390_personality, unsigned int, personality)
{
unsigned int ret;
- if (current->personality == PER_LINUX32 && personality == PER_LINUX)
- personality = PER_LINUX32;
+ if (personality(current->personality) == PER_LINUX32 &&
+ personality(personality) == PER_LINUX)
+ personality &= ~PER_LINUX | PER_LINUX32;
ret = sys_personality(personality);
- if (ret == PER_LINUX32)
- ret = PER_LINUX;
+ if (personality(ret) == PER_LINUX32)
+ ret &= ~PER_LINUX32 | PER_LINUX;
return ret;
}
--
Jiri Kosina
SUSE Labs
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