diff options
| author | Matthew Rosato <mjrosato@linux.ibm.com> | 2025-08-27 17:08:27 -0400 |
|---|---|---|
| committer | Joerg Roedel <joerg.roedel@amd.com> | 2025-09-05 15:11:07 +0200 |
| commit | b3506e9bcc777ed6af2ab631c86a9990ed97b474 (patch) | |
| tree | d6cf84e51c98226e73a87d1edc913e6362c180d0 | |
| parent | 923b70581cb6acede90f8aaf4afe5d1c58c67b71 (diff) | |
iommu/s390: Fix memory corruption when using identity domain
zpci_get_iommu_ctrs() returns counter information to be reported as part
of device statistics; these counters are stored as part of the s390_domain.
The problem, however, is that the identity domain is not backed by an
s390_domain and so the conversion via to_s390_domain() yields a bad address
that is zero'd initially and read on-demand later via a sysfs read.
These counters aren't necessary for the identity domain; just return NULL
in this case.
This issue was discovered via KASAN with reports that look like:
BUG: KASAN: global-out-of-bounds in zpci_fmb_enable_device
when using the identity domain for a device on s390.
Cc: stable@vger.kernel.org
Fixes: 64af12c6ec3a ("iommu/s390: implement iommu passthrough via identity domain")
Reported-by: Cam Miller <cam@linux.ibm.com>
Signed-off-by: Matthew Rosato <mjrosato@linux.ibm.com>
Tested-by: Cam Miller <cam@linux.ibm.com>
Reviewed-by: Farhan Ali <alifm@linux.ibm.com>
Reviewed-by: Niklas Schnelle <schnelle@linux.ibm.com>
Link: https://lore.kernel.org/r/20250827210828.274527-1-mjrosato@linux.ibm.com
Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>
| -rw-r--r-- | drivers/iommu/s390-iommu.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c index 9c80d61deb2c..d7370347c910 100644 --- a/drivers/iommu/s390-iommu.c +++ b/drivers/iommu/s390-iommu.c @@ -1032,7 +1032,8 @@ struct zpci_iommu_ctrs *zpci_get_iommu_ctrs(struct zpci_dev *zdev) lockdep_assert_held(&zdev->dom_lock); - if (zdev->s390_domain->type == IOMMU_DOMAIN_BLOCKED) + if (zdev->s390_domain->type == IOMMU_DOMAIN_BLOCKED || + zdev->s390_domain->type == IOMMU_DOMAIN_IDENTITY) return NULL; s390_domain = to_s390_domain(zdev->s390_domain); |