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authorAndrey Ryabinin <arbn@yandex-team.com>2021-02-17 17:30:04 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-03-11 14:05:01 +0100
commit4ed2042cb8c2ee90f027c03287b1e1355c3fa077 (patch)
treecd3f9146514c71f6f3b4666b818ffa68b31a77c5 /drivers
parentc6547dc1e3753382a58bc339a24ed4ef04b09dd3 (diff)
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iommu/amd: Fix sleeping in atomic in increase_address_space()
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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/iommu/amd_iommu.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c
index d0cbe910ee9d..5d5941aca16a 100644
--- a/drivers/iommu/amd_iommu.c
+++ b/drivers/iommu/amd_iommu.c
@@ -1348,24 +1348,26 @@ static void increase_address_space(struct protection_domain *domain,
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;
}