This is a note to let you know that I've just added the patch titled
s390/vmem: fix empty page tables cleanup under KASAN
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
s390-vmem-fix-empty-page-tables-cleanup-under-kasan.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit e88bf54b722a75a8a6ac5e609eb9aebc52391253
Author: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Date: Sat Jan 28 17:35:12 2023 +0100
s390/vmem: fix empty page tables cleanup under KASAN
[ Upstream commit 108303b0a2d27cb14eed565e33e64ad9eefe5d7e ]
Commit b9ff81003cf1 ("s390/vmem: cleanup empty page tables") introduced
empty page tables cleanup in vmem code, but when the kernel is built
with KASAN enabled the code has no effect due to wrong KASAN shadow
memory intersection condition, which effectively ignores any memory
range below KASAN shadow. Fix intersection condition to make code
work as anticipated.
Fixes: b9ff81003cf1 ("s390/vmem: cleanup empty page tables")
Reviewed-by: Alexander Gordeev <agordeev@xxxxxxxxxxxxx>
Signed-off-by: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/s390/mm/vmem.c b/arch/s390/mm/vmem.c
index ee1a97078527b..9a0ce5315f36d 100644
--- a/arch/s390/mm/vmem.c
+++ b/arch/s390/mm/vmem.c
@@ -297,7 +297,7 @@ static void try_free_pmd_table(pud_t *pud, unsigned long start)
if (end > VMALLOC_START)
return;
#ifdef CONFIG_KASAN
- if (start < KASAN_SHADOW_END && KASAN_SHADOW_START > end)
+ if (start < KASAN_SHADOW_END && end > KASAN_SHADOW_START)
return;
#endif
pmd = pmd_offset(pud, start);
@@ -372,7 +372,7 @@ static void try_free_pud_table(p4d_t *p4d, unsigned long start)
if (end > VMALLOC_START)
return;
#ifdef CONFIG_KASAN
- if (start < KASAN_SHADOW_END && KASAN_SHADOW_START > end)
+ if (start < KASAN_SHADOW_END && end > KASAN_SHADOW_START)
return;
#endif
@@ -426,7 +426,7 @@ static void try_free_p4d_table(pgd_t *pgd, unsigned long start)
if (end > VMALLOC_START)
return;
#ifdef CONFIG_KASAN
- if (start < KASAN_SHADOW_END && KASAN_SHADOW_START > end)
+ if (start < KASAN_SHADOW_END && end > KASAN_SHADOW_START)
return;
#endif
