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authorRobin Murphy <robin.murphy@arm.com>2020-06-02 16:08:18 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2020-09-03 12:29:16 +0300
commitc71c249310b535e91b0991489f08a469b678838a (patch)
treedb0b53b86db057977e4007df6c8bd3bc7718f328 /drivers/iommu
parent8bcd6545f0b409e86b7b9b51ae1a51e037816a7d (diff)
downloadlinux-c71c249310b535e91b0991489f08a469b678838a.tar.xz
iommu/iova: Don't BUG on invalid PFNs
[ Upstream commit d3e3d2be688b4b5864538de61e750721a311e4fc ] Unlike the other instances which represent a complete loss of consistency within the rcache mechanism itself, or a fundamental and obvious misconfiguration by an IOMMU driver, the BUG_ON() in iova_magazine_free_pfns() can be provoked at more or less any time in a "spooky action-at-a-distance" manner by any old device driver passing nonsense to dma_unmap_*() which then propagates through to queue_iova(). Not only is this well outside the IOVA layer's control, it's also nowhere near fatal enough to justify panicking anyway - all that really achieves is to make debugging the offending driver more difficult. Let's simply WARN and otherwise ignore bogus PFNs. Reported-by: Prakash Gupta <guptap@codeaurora.org> Signed-off-by: Robin Murphy <robin.murphy@arm.com> Reviewed-by: Prakash Gupta <guptap@codeaurora.org> Link: https://lore.kernel.org/r/acbd2d092b42738a03a21b417ce64e27f8c91c86.1591103298.git.robin.murphy@arm.com Signed-off-by: Joerg Roedel <jroedel@suse.de> Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/iova.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c
index 49fc01f2a28d..45a251da5453 100644
--- a/drivers/iommu/iova.c
+++ b/drivers/iommu/iova.c
@@ -811,7 +811,9 @@ iova_magazine_free_pfns(struct iova_magazine *mag, struct iova_domain *iovad)
for (i = 0 ; i < mag->size; ++i) {
struct iova *iova = private_find_iova(iovad, mag->pfns[i]);
- BUG_ON(!iova);
+ if (WARN_ON(!iova))
+ continue;
+
private_free_iova(iovad, iova);
}