"value":"In the Linux kernel, the following vulnerability has been resolved:\n\niommufd: Fix protection fault in iommufd_test_syz_conv_iova\n\nSyzkaller reported the following bug:\n\n general protection fault, probably for non-canonical address 0xdffffc0000000038: 0000 [#1] SMP KASAN\n KASAN: null-ptr-deref in range [0x00000000000001c0-0x00000000000001c7]\n Call Trace:\n lock_acquire\n lock_acquire+0x1ce/0x4f0\n down_read+0x93/0x4a0\n iommufd_test_syz_conv_iova+0x56/0x1f0\n iommufd_test_access_rw.isra.0+0x2ec/0x390\n iommufd_test+0x1058/0x1e30\n iommufd_fops_ioctl+0x381/0x510\n vfs_ioctl\n __do_sys_ioctl\n __se_sys_ioctl\n __x64_sys_ioctl+0x170/0x1e0\n do_syscall_x64\n do_syscall_64+0x71/0x140\n\nThis is because the new iommufd_access_change_ioas() sets access->ioas to\nNULL during its process, so the lock might be gone in a concurrent racing\ncontext.\n\nFix this by doing the same access->ioas sanity as iommufd_access_rw() and\niommufd_access_pin_pages() functions do."