6.6-stable review patch. If anyone has any objections, please let me know.
------------------
From: Heiko Carstens <hca@xxxxxxxxxxxxx>
commit b5efb63acf7bddaf20eacfcac654c25c446eabe8 upstream.
crst_table_free() used to work with NULL pointers before the conversion
to ptdescs. Since crst_table_free() can be called with a NULL pointer
(error handling in crst_table_upgrade() add an explicit check.
Also add the same check to base_crst_free() for consistency reasons.
In real life this should not happen, since order two GFP_KERNEL
allocations will not fail, unless FAIL_PAGE_ALLOC is enabled and used.
Reported-by: Yunseong Kim <yskelg@xxxxxxxxx>
Fixes: 6326c26c1514 ("s390: convert various pgalloc functions to use ptdescs")
Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Acked-by: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxx
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/s390/mm/pgalloc.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/arch/s390/mm/pgalloc.c
+++ b/arch/s390/mm/pgalloc.c
@@ -53,6 +53,8 @@ unsigned long *crst_table_alloc(struct m
void crst_table_free(struct mm_struct *mm, unsigned long *table)
{
+ if (!table)
+ return;
pagetable_free(virt_to_ptdesc(table));
}
@@ -500,6 +502,8 @@ static unsigned long *base_crst_alloc(un
static void base_crst_free(unsigned long *table)
{
+ if (!table)
+ return;
pagetable_free(virt_to_ptdesc(table));
}
