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authorJason Gunthorpe <jgg@nvidia.com>2023-03-06 20:27:04 +0300
committerJason Gunthorpe <jgg@nvidia.com>2023-03-10 22:29:59 +0300
commitfd8c1a4aee973e87d890a5861e106625a33b2c4e (patch)
treea69a838d6ec4599420ab8ebe858bf12e4fe3d62c /drivers/iommu/iommufd/selftest.c
parent4ed4791afb34c61650b17407846174a72e4034f4 (diff)
downloadlinux-fd8c1a4aee973e87d890a5861e106625a33b2c4e.tar.xz
iommufd/selftest: Catch overflow of uptr and length
syzkaller hits a WARN_ON when trying to have a uptr close to UINTPTR_MAX: WARNING: CPU: 1 PID: 393 at drivers/iommu/iommufd/selftest.c:403 iommufd_test+0xb19/0x16f0 Modules linked in: CPU: 1 PID: 393 Comm: repro Not tainted 6.2.0-c9c3395d5e3d #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 RIP: 0010:iommufd_test+0xb19/0x16f0 Code: 94 c4 31 ff 44 89 e6 e8 a5 54 17 ff 45 84 e4 0f 85 bb 0b 00 00 41 be fb ff ff ff e8 31 53 17 ff e9 a0 f7 ff ff e8 27 53 17 ff <0f> 0b 41 be 8 RSP: 0018:ffffc90000eabdc0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff8214c487 RDX: 0000000000000000 RSI: ffff88800f5c8000 RDI: 0000000000000002 RBP: ffffc90000eabe48 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000001 R11: 0000000000000000 R12: 00000000cd2b0000 R13: 00000000cd2af000 R14: 0000000000000000 R15: ffffc90000eabe68 FS: 00007f94d76d5740(0000) GS:ffff88807dd00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000043 CR3: 0000000006880006 CR4: 0000000000770ee0 PKRU: 55555554 Call Trace: <TASK> ? write_comp_data+0x2f/0x90 iommufd_fops_ioctl+0x1ef/0x310 __x64_sys_ioctl+0x10e/0x160 ? __pfx_iommufd_fops_ioctl+0x10/0x10 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc Check that the user memory range doesn't overflow. Fixes: f4b20bb34c83 ("iommufd: Add kernel support for testing iommufd") Link: https://lore.kernel.org/r/0-v1-95390ed1df8d+8f-iommufd_mock_overflow_jgg@nvidia.com Reviewed-by: Kevin Tian <kevin.tian@intel.com> Reported-by: Pengfei Xu <pengfei.xu@intel.com> Link: https://lore.kernel.org/r/Y/hOiilV1wJvu/Hv@xpf.sh.intel.com Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Diffstat (limited to 'drivers/iommu/iommufd/selftest.c')
-rw-r--r--drivers/iommu/iommufd/selftest.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c
index 17cb7b95eb27..58471f9452be 100644
--- a/drivers/iommu/iommufd/selftest.c
+++ b/drivers/iommu/iommufd/selftest.c
@@ -480,10 +480,12 @@ static int iommufd_test_md_check_pa(struct iommufd_ucmd *ucmd,
{
struct iommufd_hw_pagetable *hwpt;
struct mock_iommu_domain *mock;
+ uintptr_t end;
int rc;
if (iova % MOCK_IO_PAGE_SIZE || length % MOCK_IO_PAGE_SIZE ||
- (uintptr_t)uptr % MOCK_IO_PAGE_SIZE)
+ (uintptr_t)uptr % MOCK_IO_PAGE_SIZE ||
+ check_add_overflow((uintptr_t)uptr, (uintptr_t)length, &end))
return -EINVAL;
hwpt = get_md_pagetable(ucmd, mockpt_id, &mock);
@@ -531,7 +533,10 @@ static int iommufd_test_md_check_refs(struct iommufd_ucmd *ucmd,
void __user *uptr, size_t length,
unsigned int refs)
{
- if (length % PAGE_SIZE || (uintptr_t)uptr % PAGE_SIZE)
+ uintptr_t end;
+
+ if (length % PAGE_SIZE || (uintptr_t)uptr % PAGE_SIZE ||
+ check_add_overflow((uintptr_t)uptr, (uintptr_t)length, &end))
return -EINVAL;
for (; length; length -= PAGE_SIZE) {