This is a note to let you know that I've just added the patch titled
iommufd/selftest: Fix buffer read overrrun in the dirty test
to the 6.10-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
iommufd-selftest-fix-buffer-read-overrrun-in-the-dir.patch
and it can be found in the queue-6.10 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 94b71d04a45adb27050dc4f90b2154348f432e60
Author: Jason Gunthorpe <jgg@xxxxxxxx>
Date: Thu Aug 22 11:47:09 2024 -0300
iommufd/selftest: Fix buffer read overrrun in the dirty test
[ Upstream commit 79ea4a496ab5c970a3a793d863ed8893b1af107c ]
test_bit() is used to read the memory storing the bitmap, however
test_bit() always uses a unsigned long 8 byte access.
If the bitmap is not an aligned size of 64 bits this will now trigger a
KASAN warning reading past the end of the buffer.
Properly round the buffer allocation to an unsigned long size. Continue to
copy_from_user() using a byte granularity.
Fixes: 9560393b830b ("iommufd/selftest: Fix iommufd_test_dirty() to handle <u8 bitmaps")
Link: https://patch.msgid.link/r/0-v1-113e8d9e7861+5ae-iommufd_kasan_jgg@xxxxxxxxxx
Reviewed-by: Joao Martins <joao.m.martins@xxxxxxxxxx>
Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>
Signed-off-by: Jason Gunthorpe <jgg@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
index 654ed33390957..62bfeb7a35d85 100644
--- a/drivers/iommu/iommufd/selftest.c
+++ b/drivers/iommu/iommufd/selftest.c
@@ -1313,7 +1313,7 @@ static int iommufd_test_dirty(struct iommufd_ucmd *ucmd, unsigned int mockpt_id,
unsigned long page_size, void __user *uptr,
u32 flags)
{
- unsigned long bitmap_size, i, max;
+ unsigned long i, max;
struct iommu_test_cmd *cmd = ucmd->cmd;
struct iommufd_hw_pagetable *hwpt;
struct mock_iommu_domain *mock;
@@ -1334,15 +1334,14 @@ static int iommufd_test_dirty(struct iommufd_ucmd *ucmd, unsigned int mockpt_id,
}
max = length / page_size;
- bitmap_size = DIV_ROUND_UP(max, BITS_PER_BYTE);
-
- tmp = kvzalloc(bitmap_size, GFP_KERNEL_ACCOUNT);
+ tmp = kvzalloc(DIV_ROUND_UP(max, BITS_PER_LONG) * sizeof(unsigned long),
+ GFP_KERNEL_ACCOUNT);
if (!tmp) {
rc = -ENOMEM;
goto out_put;
}
- if (copy_from_user(tmp, uptr, bitmap_size)) {
+ if (copy_from_user(tmp, uptr,DIV_ROUND_UP(max, BITS_PER_BYTE))) {
rc = -EFAULT;
goto out_free;
}
