From: "XianLiang Huang" <huangxianliang@lanxincomputing.com>
To: <tjeznach@rivosinc.com>
Cc: <markus.elfring@web.de>, <joro@8bytes.org>, <will@kernel.org>,
<robin.murphy@arm.com>, <paul.walmsley@sifive.com>,
<palmer@dabbelt.com>, <aou@eecs.berkeley.edu>, <alex@ghiti.fr>,
<iommu@lists.linux.dev>, <linux-riscv@lists.infradead.org>,
<linux-kernel@vger.kernel.org>,
<huangxianliang@lanxincomputing.com>
Subject: [PATCH v4] iommu/riscv: prevent NULL deref in iova_to_phys
Date: Wed, 20 Aug 2025 15:22:48 +0800 [thread overview]
Message-ID: <20250820072248.312-1-huangxianliang@lanxincomputing.com> (raw)
The riscv_iommu_pte_fetch() function returns either NULL for
unmapped/never-mapped iova, or a valid leaf pte pointer that requires no
further validation.
riscv_iommu_iova_to_phys() failed to handle NULL returns. Prevent null pointer
dereference in riscv_iommu_iova_to_phys(), and remove the pte validation.
Fixes: 488ffbf18171 ("iommu/riscv: Paging domain support")
Cc: Tomasz Jeznach <tjeznach@rivosinc.com>
Signed-off-by: XianLiang Huang <huangxianliang@lanxincomputing.com>
---
Changes
v4:
- Change the summary as Markus recommends
v3:
- Remove redundant pte validation in riscv_iommu_iova_to_phys
- Improve subject line to emphasize prevention
v2:
- Refine problem description
- Add "Fixes" tag
---
drivers/iommu/riscv/iommu.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/iommu/riscv/iommu.c b/drivers/iommu/riscv/iommu.c
index 2d0d31ba2886..0eae2f4bdc5e 100644
--- a/drivers/iommu/riscv/iommu.c
+++ b/drivers/iommu/riscv/iommu.c
@@ -1283,7 +1283,7 @@ static phys_addr_t riscv_iommu_iova_to_phys(struct iommu_domain *iommu_domain,
unsigned long *ptr;
ptr = riscv_iommu_pte_fetch(domain, iova, &pte_size);
- if (_io_pte_none(*ptr) || !_io_pte_present(*ptr))
+ if (!ptr)
return 0;
return pfn_to_phys(__page_val_to_pfn(*ptr)) | (iova & (pte_size - 1));
--
2.34.1
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next reply other threads:[~2025-08-20 7:38 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-08-20 7:22 XianLiang Huang [this message]
2025-08-20 8:25 ` [PATCH v4] iommu/riscv: prevent NULL deref in iova_to_phys Markus Elfring
2025-08-20 9:21 ` XianLiang Huang
2025-08-20 10:40 ` [v4] " Markus Elfring
2025-08-20 11:16 ` XianLiang Huang
2025-08-20 11:30 ` Markus Elfring
2025-08-22 2:36 ` XianLiang Huang
2025-08-22 6:52 ` [PATCH v4] " Joerg Roedel
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