diff options
| author | Nicolin Chen <nicolinc@nvidia.com> | 2024-02-22 22:23:47 +0100 |
|---|---|---|
| committer | Jason Gunthorpe <jgg@nvidia.com> | 2024-02-26 21:58:11 +0100 |
| commit | cf7c2789822db8b5efa34f5ebcf1621bc0008d48 (patch) | |
| tree | f9d2a7f055cdfa3756b46e5f4dc62bd1eb72f97a /drivers/iommu/iommufd | |
| parent | iommufd/selftest: Fix mock_dev_num bug (diff) | |
| download | linux-cf7c2789822db8b5efa34f5ebcf1621bc0008d48.tar.xz linux-cf7c2789822db8b5efa34f5ebcf1621bc0008d48.zip | |
iommufd: Fix protection fault in iommufd_test_syz_conv_iova
Syzkaller reported the following bug:
general protection fault, probably for non-canonical address 0xdffffc0000000038: 0000 [#1] SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000001c0-0x00000000000001c7]
Call Trace:
lock_acquire
lock_acquire+0x1ce/0x4f0
down_read+0x93/0x4a0
iommufd_test_syz_conv_iova+0x56/0x1f0
iommufd_test_access_rw.isra.0+0x2ec/0x390
iommufd_test+0x1058/0x1e30
iommufd_fops_ioctl+0x381/0x510
vfs_ioctl
__do_sys_ioctl
__se_sys_ioctl
__x64_sys_ioctl+0x170/0x1e0
do_syscall_x64
do_syscall_64+0x71/0x140
This is because the new iommufd_access_change_ioas() sets access->ioas to
NULL during its process, so the lock might be gone in a concurrent racing
context.
Fix this by doing the same access->ioas sanity as iommufd_access_rw() and
iommufd_access_pin_pages() functions do.
Cc: stable@vger.kernel.org
Fixes: 9227da7816dd ("iommufd: Add iommufd_access_change_ioas(_id) helpers")
Link: https://lore.kernel.org/r/3f1932acaf1dd494d404c04364d73ce8f57f3e5e.1708636627.git.nicolinc@nvidia.com
Reported-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Diffstat (limited to 'drivers/iommu/iommufd')
| -rw-r--r-- | drivers/iommu/iommufd/selftest.c | 27 |
1 files changed, 21 insertions, 6 deletions
diff --git a/drivers/iommu/iommufd/selftest.c b/drivers/iommu/iommufd/selftest.c index 2bfe77bd351d..d59e199a8705 100644 --- a/drivers/iommu/iommufd/selftest.c +++ b/drivers/iommu/iommufd/selftest.c @@ -63,8 +63,8 @@ enum { * In syzkaller mode the 64 bit IOVA is converted into an nth area and offset * value. This has a much smaller randomization space and syzkaller can hit it. */ -static unsigned long iommufd_test_syz_conv_iova(struct io_pagetable *iopt, - u64 *iova) +static unsigned long __iommufd_test_syz_conv_iova(struct io_pagetable *iopt, + u64 *iova) { struct syz_layout { __u32 nth_area; @@ -88,6 +88,21 @@ static unsigned long iommufd_test_syz_conv_iova(struct io_pagetable *iopt, return 0; } +static unsigned long iommufd_test_syz_conv_iova(struct iommufd_access *access, + u64 *iova) +{ + unsigned long ret; + + mutex_lock(&access->ioas_lock); + if (!access->ioas) { + mutex_unlock(&access->ioas_lock); + return 0; + } + ret = __iommufd_test_syz_conv_iova(&access->ioas->iopt, iova); + mutex_unlock(&access->ioas_lock); + return ret; +} + void iommufd_test_syz_conv_iova_id(struct iommufd_ucmd *ucmd, unsigned int ioas_id, u64 *iova, u32 *flags) { @@ -100,7 +115,7 @@ void iommufd_test_syz_conv_iova_id(struct iommufd_ucmd *ucmd, ioas = iommufd_get_ioas(ucmd->ictx, ioas_id); if (IS_ERR(ioas)) return; - *iova = iommufd_test_syz_conv_iova(&ioas->iopt, iova); + *iova = __iommufd_test_syz_conv_iova(&ioas->iopt, iova); iommufd_put_object(ucmd->ictx, &ioas->obj); } @@ -1161,7 +1176,7 @@ static int iommufd_test_access_pages(struct iommufd_ucmd *ucmd, } if (flags & MOCK_FLAGS_ACCESS_SYZ) - iova = iommufd_test_syz_conv_iova(&staccess->access->ioas->iopt, + iova = iommufd_test_syz_conv_iova(staccess->access, &cmd->access_pages.iova); npages = (ALIGN(iova + length, PAGE_SIZE) - @@ -1263,8 +1278,8 @@ static int iommufd_test_access_rw(struct iommufd_ucmd *ucmd, } if (flags & MOCK_FLAGS_ACCESS_SYZ) - iova = iommufd_test_syz_conv_iova(&staccess->access->ioas->iopt, - &cmd->access_rw.iova); + iova = iommufd_test_syz_conv_iova(staccess->access, + &cmd->access_rw.iova); rc = iommufd_access_rw(staccess->access, iova, tmp, length, flags); if (rc) |