parisc: Fix data TLB miss in sba_unmap_sg

published 2024-07-16 2 y ago modified 2026-06-17 4 mo ago also EUVD-2022-53674

cvss: 5.5; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 0.2%; EPSS 0.2% chance of exploitation in 30 days, percentile 15%
public exploits: 0; none known

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

Rolf Eike Beer reported the following bug:

[1274934.746891] Bad Address (null pointer deref?): Code=15 (Data TLB miss fault) at addr 0000004140000018 [1274934.746891] CPU: 3 PID: 5549 Comm: cmake Not tainted 5.15.4-gentoo-parisc64 #4 [1274934.746891] Hardware name: 9000/785/C8000 [1274934.746891] [1274934.746891] YZrvWESTHLNXBCVMcbcbcbcbOGFRQPDI [1274934.746891] PSW: 00001000000001001111111000001110 Not tainted [1274934.746891] r00-03 000000ff0804fe0e 0000000040bc9bc0 00000000406760e4 0000004140000000 [1274934.746891] r04-07 0000000040b693c0 0000004140000000 000000004a2b08b0 0000000000000001 [1274934.746891] r08-11 0000000041f98810 0000000000000000 000000004a0a7000 0000000000000001 [1274934.746891] r12-15 0000000040bddbc0 0000000040c0cbc0 0000000040bddbc0 0000000040bddbc0 [1274934.746891] r16-19 0000000040bde3c0 0000000040bddbc0 0000000040bde3c0 0000000000000007 [1274934.746891] r20-23 0000000000000006 000000004a368950 0000000000000000 0000000000000001 [1274934.746891] r24-27 0000000000001fff 000000000800000e 000000004a1710f0 0000000040b693c0 [1274934.746891] r28-31 0000000000000001 0000000041f988b0 0000000041f98840 000000004a171118 [1274934.746891] sr00-03 00000000066e5800 0000000000000000 0000000000000000 00000000066e5800 [1274934.746891] sr04-07 0000000000000000 0000000000000000 0000000000000000 0000000000000000 [1274934.746891] [1274934.746891] IASQ: 0000000000000000 0000000000000000 IAOQ: 00000000406760e8 00000000406760ec [1274934.746891] IIR: 48780030 ISR: 0000000000000000 IOR: 0000004140000018 [1274934.746891] CPU: 3 CR30: 00000040e3a9c000 CR31: ffffffffffffffff [1274934.746891] ORIG_R28: 0000000040acdd58 [1274934.746891] IAOQ[0]: sba_unmap_sg+0xb0/0x118 [1274934.746891] IAOQ[1]: sba_unmap_sg+0xb4/0x118 [1274934.746891] RP(r2): sba_unmap_sg+0xac/0x118 [1274934.746891] Backtrace: [1274934.746891] [<00000000402740cc>] dma_unmap_sg_attrs+0x6c/0x70 [1274934.746891] [<000000004074d6bc>] scsi_dma_unmap+0x54/0x60 [1274934.746891] [<00000000407a3488>] mptscsih_io_done+0x150/0xd70 [1274934.746891] [<0000000040798600>] mpt_interrupt+0x168/0xa68 [1274934.746891] [<0000000040255a48>] __handle_irq_event_percpu+0xc8/0x278 [1274934.746891] [<0000000040255c34>] handle_irq_event_percpu+0x3c/0xd8 [1274934.746891] [<000000004025ecb4>] handle_percpu_irq+0xb4/0xf0 [1274934.746891] [<00000000402548e0>] generic_handle_irq+0x50/0x70 [1274934.746891] [<000000004019a254>] call_on_stack+0x18/0x24 [1274934.746891] [1274934.746891] Kernel panic - not syncing: Bad Address (null pointer deref?)

The bug is caused by overrunning the sglist and incorrectly testing sg_dma_len(sglist) before nents. Normally this doesn't cause a crash, but in this case sglist crossed a page boundary. This occurs in the following code:

while (sg_dma_len(sglist) && nents--) {

The fix is simply to test nents first and move the decrement of nents into the loop.

Patch / fix

fixed in 1 distros 2 links 8

Linux Linux 4.9.303, 4.14.268, 4.19.231, 5.4.181, 5.10.102, 5.15.25, 5.16.11, 5.17

debian ubuntu

linux Debian 14, Debian 13, Debian 12 5.16.11-1

debian advisories DEBIAN-CVE-2022-48795

linux Ubuntu 18.04 LTS 4.15.0-177.186
linux Ubuntu 20.04 LTS 5.4.0-110.124
linux-aws Ubuntu 18.04 LTS 4.15.0-1128.137
linux-aws Ubuntu 20.04 LTS 5.4.0-1073.78
linux-gcp Ubuntu 20.04 LTS 5.4.0-1073.78
linux-ibm Ubuntu 20.04 LTS 5.4.0-1021.23
linux-iot Ubuntu 20.04 LTS 5.4.0-1004.6
linux-kvm Ubuntu 18.04 LTS 4.15.0-1114.117

ubuntu advisories UBUNTU-CVE-2022-48795

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2022-48795 updated 2026-11-05 cvss 5.5

kernel: parisc: Fix data TLB miss in sba_unmap_sg

Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation: none
Automatable: no
Technical impact: partial
Assessed: 2 y ago (2024-09-10)

Exploit prediction

0.24% chance of exploitation in the next 30 days, higher than 15% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
NVD	3.1	5.5	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

Linux Linux

Classification

Technology feeds

Linux kernel rss critical rss

References

Sources

CVE List CVE-2022-48795
NVD CVE-2022-48795

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

Summary