CVE-2023-53630
Description
From CVE.org
In the Linux kernel, the following vulnerability has been resolved: iommufd: Fix unpinning of pages when an access is present syzkaller found that the calculation of batch_last_index should use 'start_index' since at input to this function the batch is either empty or it has already been adjusted to cross any accesses so it will start at the point we are unmapping from. Getting this wrong causes the unmap to run over the end of the pages which corrupts pages that were never mapped. In most cases this triggers the num pinned debugging: WARNING: CPU: 0 PID: 557 at drivers/iommu/iommufd/pages.c:294 __iopt_area_unfill_domain+0x152/0x560 Modules linked in: CPU: 0 PID: 557 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:__iopt_area_unfill_domain+0x152/0x560 Code: d2 0f ff 44 8b 64 24 54 48 8b 44 24 48 31 ff 44 89 e6 48 89 44 24 38 e8 fc d3 0f ff 45 85 e4 0f 85 eb 01 00 00 e8 0e d2 0f ff <0f> 0b e8 07 d2 0f ff 48 8b 44 24 38 89 5c 24 58 89 18 8b 44 24 54 RSP: 0018:ffffc9000108baf0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 00000000ffffffff RCX: ffffffff821e3f85 RDX: 0000000000000000 RSI: ffff88800faf0000 RDI: 0000000000000002 RBP: ffffc9000108bd18 R08: 000000000003ca25 R09: 0000000000000014 R10: 000000000003ca00 R11: 0000000000000024 R12: 0000000000000004 R13: 0000000000000801 R14: 00000000000007ff R15: 0000000000000800 FS: 00007f3499ce1740(0000) GS:ffff88807dc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000020000243 CR3: 00000000179c2001 CR4: 0000000000770ef0 PKRU: 55555554 Call Trace: <TASK> iopt_area_unfill_domain+0x32/0x40 iopt_table_remove_domain+0x23f/0x4c0 iommufd_device_selftest_detach+0x3a/0x90 iommufd_selftest_destroy+0x55/0x70 iommufd_object_destroy_user+0xce/0x130 iommufd_destroy+0xa2/0xc0 iommufd_fops_ioctl+0x206/0x330 __x64_sys_ioctl+0x10e/0x160 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x72/0xdc Also add some useful WARN_ON sanity checks.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.4 | 5.5 | 8.8 |
| Attack Vector | Local | Local | Local |
| Attack Complexity | High | Low | Low |
| Privileges Required | High | Low | Low |
| User Interaction | None | None | None |
| Scope | Unchanged | Unchanged | Changed |
| Confidentiality | High | None | High |
| Integrity Impact | High | None | High |
| Availability Impact | High | High | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Understanding the Weakness (CWE)
Integrity,Availability,Confidentiality
Technical Impact: DoS: Crash, Exit, or Restart; Execute Unauthorized Code or Commands; Read Memory; Modify Memory
If the incorrect calculation is used in the context of memory allocation, then the software may create a buffer that is smaller or larger than expected. If the allocated buffer is smaller than expected, this could lead to an out-of-bounds read or write (CWE-119), possibly causing a crash, allowing arbitrary code execution, or exposing sensitive data.
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