| From 140456f994195b568ecd7fc2287a34eadffef3ca Mon Sep 17 00:00:00 2001 |
| From: Andrey Ryabinin <arbn@yandex-team.com> |
| Date: Wed, 17 Feb 2021 17:30:04 +0300 |
| Subject: iommu/amd: Fix sleeping in atomic in increase_address_space() |
| |
| From: Andrey Ryabinin <arbn@yandex-team.com> |
| |
| commit 140456f994195b568ecd7fc2287a34eadffef3ca upstream. |
| |
| increase_address_space() calls get_zeroed_page(gfp) under spin_lock with |
| disabled interrupts. gfp flags passed to increase_address_space() may allow |
| sleeping, so it comes to this: |
| |
| BUG: sleeping function called from invalid context at mm/page_alloc.c:4342 |
| in_atomic(): 1, irqs_disabled(): 1, pid: 21555, name: epdcbbf1qnhbsd8 |
| |
| Call Trace: |
| dump_stack+0x66/0x8b |
| ___might_sleep+0xec/0x110 |
| __alloc_pages_nodemask+0x104/0x300 |
| get_zeroed_page+0x15/0x40 |
| iommu_map_page+0xdd/0x3e0 |
| amd_iommu_map+0x50/0x70 |
| iommu_map+0x106/0x220 |
| vfio_iommu_type1_ioctl+0x76e/0x950 [vfio_iommu_type1] |
| do_vfs_ioctl+0xa3/0x6f0 |
| ksys_ioctl+0x66/0x70 |
| __x64_sys_ioctl+0x16/0x20 |
| do_syscall_64+0x4e/0x100 |
| entry_SYSCALL_64_after_hwframe+0x44/0xa9 |
| |
| Fix this by moving get_zeroed_page() out of spin_lock/unlock section. |
| |
| Fixes: 754265bcab ("iommu/amd: Fix race in increase_address_space()") |
| Signed-off-by: Andrey Ryabinin <arbn@yandex-team.com> |
| Acked-by: Will Deacon <will@kernel.org> |
| Cc: <stable@vger.kernel.org> |
| Link: https://lore.kernel.org/r/20210217143004.19165-1-arbn@yandex-team.com |
| Signed-off-by: Joerg Roedel <jroedel@suse.de> |
| Signed-off-by: Andrey Ryabinin <arbn@yandex-team.com> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| drivers/iommu/amd_iommu.c | 10 ++++++---- |
| 1 file changed, 6 insertions(+), 4 deletions(-) |
| |
| --- a/drivers/iommu/amd_iommu.c |
| +++ b/drivers/iommu/amd_iommu.c |
| @@ -1347,24 +1347,26 @@ static void increase_address_space(struc |
| unsigned long flags; |
| u64 *pte; |
| |
| + pte = (void *)get_zeroed_page(gfp); |
| + if (!pte) |
| + return; |
| + |
| spin_lock_irqsave(&domain->lock, flags); |
| |
| if (WARN_ON_ONCE(domain->mode == PAGE_MODE_6_LEVEL)) |
| /* address space already 64 bit large */ |
| goto out; |
| |
| - pte = (void *)get_zeroed_page(gfp); |
| - if (!pte) |
| - goto out; |
| - |
| *pte = PM_LEVEL_PDE(domain->mode, |
| iommu_virt_to_phys(domain->pt_root)); |
| domain->pt_root = pte; |
| domain->mode += 1; |
| domain->updated = true; |
| + pte = NULL; |
| |
| out: |
| spin_unlock_irqrestore(&domain->lock, flags); |
| + free_page((unsigned long)pte); |
| |
| return; |
| } |