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authorAndrey Ryabinin <arbn@yandex-team.com>2021-02-17 17:30:04 +0300
committerJoerg Roedel <jroedel@suse.de>2021-03-04 15:15:56 +0300
commit140456f994195b568ecd7fc2287a34eadffef3ca (patch)
tree1e4ac114d3b9f5d6aa11e434f54bbe62828b0ecd /drivers/iommu
parent45e606f2726926b04094e1c9bf809bca4884c57f (diff)
downloadlinux-140456f994195b568ecd7fc2287a34eadffef3ca.tar.xz
iommu/amd: Fix sleeping in atomic in increase_address_space()
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>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/amd/io_pgtable.c10
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/iommu/amd/io_pgtable.c b/drivers/iommu/amd/io_pgtable.c
index 1c4961e05c12..bb0ee5c9fde7 100644
--- a/drivers/iommu/amd/io_pgtable.c
+++ b/drivers/iommu/amd/io_pgtable.c
@@ -182,6 +182,10 @@ static bool increase_address_space(struct protection_domain *domain,
bool ret = true;
u64 *pte;
+ pte = (void *)get_zeroed_page(gfp);
+ if (!pte)
+ return false;
+
spin_lock_irqsave(&domain->lock, flags);
if (address <= PM_LEVEL_SIZE(domain->iop.mode))
@@ -191,10 +195,6 @@ static bool increase_address_space(struct protection_domain *domain,
if (WARN_ON_ONCE(domain->iop.mode == PAGE_MODE_6_LEVEL))
goto out;
- pte = (void *)get_zeroed_page(gfp);
- if (!pte)
- goto out;
-
*pte = PM_LEVEL_PDE(domain->iop.mode, iommu_virt_to_phys(domain->iop.root));
domain->iop.root = pte;
@@ -208,10 +208,12 @@ static bool increase_address_space(struct protection_domain *domain,
*/
amd_iommu_domain_set_pgtable(domain, pte, domain->iop.mode);
+ pte = NULL;
ret = true;
out:
spin_unlock_irqrestore(&domain->lock, flags);
+ free_page((unsigned long)pte);
return ret;
}