linux-cve-announce - CVE-2025-71087: iavf: fix off-by-one issues in iavf_config_rss

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [day] [month] [year] [list]
Message-ID: <2026011340-CVE-2025-71087-53c4@gregkh>
Date: Tue, 13 Jan 2026 16:35:46 +0100
From: Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To: linux-cve-announce@...r.kernel.org
Cc: Greg Kroah-Hartman <gregkh@...nel.org>
Subject: CVE-2025-71087: iavf: fix off-by-one issues in iavf_config_rss_reg()

From: Greg Kroah-Hartman <gregkh@...nel.org>

Description
===========

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

iavf: fix off-by-one issues in iavf_config_rss_reg()

There are off-by-one bugs when configuring RSS hash key and lookup
table, causing out-of-bounds reads to memory [1] and out-of-bounds
writes to device registers.

Before commit 43a3d9ba34c9 ("i40evf: Allow PF driver to configure RSS"),
the loop upper bounds were:
    i <= I40E_VFQF_{HKEY,HLUT}_MAX_INDEX
which is safe since the value is the last valid index.

That commit changed the bounds to:
    i <= adapter->rss_{key,lut}_size / 4
where `rss_{key,lut}_size / 4` is the number of dwords, so the last
valid index is `(rss_{key,lut}_size / 4) - 1`. Therefore, using `<=`
accesses one element past the end.

Fix the issues by using `<` instead of `<=`, ensuring we do not exceed
the bounds.

[1] KASAN splat about rss_key_size off-by-one
  BUG: KASAN: slab-out-of-bounds in iavf_config_rss+0x619/0x800
  Read of size 4 at addr ffff888102c50134 by task kworker/u8:6/63

  CPU: 0 UID: 0 PID: 63 Comm: kworker/u8:6 Not tainted 6.18.0-rc2-enjuk-tnguy-00378-g3005f5b77652-dirty #156 PREEMPT(voluntary)
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
  Workqueue: iavf iavf_watchdog_task
  Call Trace:
   <TASK>
   dump_stack_lvl+0x6f/0xb0
   print_report+0x170/0x4f3
   kasan_report+0xe1/0x1a0
   iavf_config_rss+0x619/0x800
   iavf_watchdog_task+0x2be7/0x3230
   process_one_work+0x7fd/0x1420
   worker_thread+0x4d1/0xd40
   kthread+0x344/0x660
   ret_from_fork+0x249/0x320
   ret_from_fork_asm+0x1a/0x30
   </TASK>

  Allocated by task 63:
   kasan_save_stack+0x30/0x50
   kasan_save_track+0x14/0x30
   __kasan_kmalloc+0x7f/0x90
   __kmalloc_noprof+0x246/0x6f0
   iavf_watchdog_task+0x28fc/0x3230
   process_one_work+0x7fd/0x1420
   worker_thread+0x4d1/0xd40
   kthread+0x344/0x660
   ret_from_fork+0x249/0x320
   ret_from_fork_asm+0x1a/0x30

  The buggy address belongs to the object at ffff888102c50100
   which belongs to the cache kmalloc-64 of size 64
  The buggy address is located 0 bytes to the right of
   allocated 52-byte region [ffff888102c50100, ffff888102c50134)

  The buggy address belongs to the physical page:
  page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x102c50
  flags: 0x200000000000000(node=0|zone=2)
  page_type: f5(slab)
  raw: 0200000000000000 ffff8881000418c0 dead000000000122 0000000000000000
  raw: 0000000000000000 0000000080200020 00000000f5000000 0000000000000000
  page dumped because: kasan: bad access detected

  Memory state around the buggy address:
   ffff888102c50000: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc
   ffff888102c50080: 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc fc
  >ffff888102c50100: 00 00 00 00 00 00 04 fc fc fc fc fc fc fc fc fc
                                       ^
   ffff888102c50180: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
   ffff888102c50200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc

The Linux kernel CVE team has assigned CVE-2025-71087 to this issue.


Affected and fixed versions
===========================

	Issue introduced in 4.7 with commit 43a3d9ba34c9ca313573201d3f45de5ab3494cec and fixed in 6.1.160 with commit d7369dc8dd7cbf5cee3a22610028d847b6f02982
	Issue introduced in 4.7 with commit 43a3d9ba34c9ca313573201d3f45de5ab3494cec and fixed in 6.6.120 with commit 18de0e41d69d97fab10b91fecf10ae78a5e43232
	Issue introduced in 4.7 with commit 43a3d9ba34c9ca313573201d3f45de5ab3494cec and fixed in 6.12.64 with commit f36de3045d006e6d9be1be495f2ed88d1721e752
	Issue introduced in 4.7 with commit 43a3d9ba34c9ca313573201d3f45de5ab3494cec and fixed in 6.18.4 with commit 3095228e1320371e143835d0cebeef1a8a754c66
	Issue introduced in 4.7 with commit 43a3d9ba34c9ca313573201d3f45de5ab3494cec and fixed in 6.19-rc4 with commit 6daa2893f323981c7894c68440823326e93a7d61

Please see https://www.kernel.org for a full list of currently supported
kernel versions by the kernel community.

Unaffected versions might change over time as fixes are backported to
older supported kernel versions.  The official CVE entry at
	https://cve.org/CVERecord/?id=CVE-2025-71087
will be updated if fixes are backported, please check that for the most
up to date information about this issue.


Affected files
==============

The file(s) affected by this issue are:
	drivers/net/ethernet/intel/iavf/iavf_main.c


Mitigation
==========

The Linux kernel CVE team recommends that you update to the latest
stable kernel version for this, and many other bugfixes.  Individual
changes are never tested alone, but rather are part of a larger kernel
release.  Cherry-picking individual commits is not recommended or
supported by the Linux kernel community at all.  If however, updating to
the latest release is impossible, the individual changes to resolve this
issue can be found at these commits:
	https://git.kernel.org/stable/c/d7369dc8dd7cbf5cee3a22610028d847b6f02982
	https://git.kernel.org/stable/c/18de0e41d69d97fab10b91fecf10ae78a5e43232
	https://git.kernel.org/stable/c/f36de3045d006e6d9be1be495f2ed88d1721e752
	https://git.kernel.org/stable/c/3095228e1320371e143835d0cebeef1a8a754c66
	https://git.kernel.org/stable/c/6daa2893f323981c7894c68440823326e93a7d61