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 5.15-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-5.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit f4639ddf41190b7217873474a7487ed12b8d911d 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 2b1c6d916cf9c..39912629b0619 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