CVE-2023-53236

In the Linux kernel, the following vulnerability has been resolved:

iommufd: Do not corrupt the pfn list when doing batch carry

If batch->end is 0 then setting npfns[0] before computing the new value of

pfns will fail to adjust the pfn and result in various page accounting

corruptions. It should be ordered after.

This seems to result in various kinds of page meta-data corruption related

failures:

WARNING: CPU: 1 PID: 527 at mm/gup.c:75 try_grab_folio+0x503/0x740

Modules linked in:

CPU: 1 PID: 527 Comm: repro Not tainted 6.3.0-rc2-eeac8ede1755+ #1

Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014

RIP: 0010:try_grab_folio+0x503/0x740

Code: e3 01 48 89 de e8 6d c1 dd ff 48 85 db 0f 84 7c fe ff ff e8 4f bf dd ff 49 8d 47 ff 48 89 45 d0 e9 73 fe ff ff e8 3d bf dd ff <0f> 0b 31 db e9 d0 fc ff ff e8 2f bf dd ff 48 8b 5d c8 31 ff 48 89

RSP: 0018:ffffc90000f37908 EFLAGS: 00010046

RAX: 0000000000000000 RBX: 00000000fffffc02 RCX: ffffffff81504c26

RDX: 0000000000000000 RSI: ffff88800d030000 RDI: 0000000000000002

RBP: ffffc90000f37948 R08: 000000000003ca24 R09: 0000000000000008

R10: 000000000003ca00 R11: 0000000000000023 R12: ffffea000035d540

R13: 0000000000000001 R14: 0000000000000000 R15: ffffea000035d540

FS: 00007fecbf659740(0000) GS:ffff88807dd00000(0000) knlGS:0000000000000000

CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033

CR2: 00000000200011c3 CR3: 000000000ef66006 CR4: 0000000000770ee0

PKRU: 55555554

Call Trace:

<TASK>

internal_get_user_pages_fast+0xd32/0x2200

pin_user_pages_fast+0x65/0x90

pfn_reader_user_pin+0x376/0x390

pfn_reader_next+0x14a/0x7b0

pfn_reader_first+0x140/0x1b0

iopt_area_fill_domain+0x74/0x210

iopt_table_add_domain+0x30e/0x6e0

iommufd_device_selftest_attach+0x7f/0x140

iommufd_test+0x10ff/0x16f0

iommufd_fops_ioctl+0x206/0x330

__x64_sys_ioctl+0x10e/0x160

do_syscall_64+0x3b/0x90

entry_SYSCALL_64_after_hwframe+0x72/0xdc