Upstream information

CVE-2024-26759 at MITRE

Description

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

mm/swap: fix race when skipping swapcache

When skipping swapcache for SWP_SYNCHRONOUS_IO, if two or more threads
swapin the same entry at the same time, they get different pages (A, B).
Before one thread (T0) finishes the swapin and installs page (A) to the
PTE, another thread (T1) could finish swapin of page (B), swap_free the
entry, then swap out the possibly modified page reusing the same entry.
It breaks the pte_same check in (T0) because PTE value is unchanged,
causing ABA problem. Thread (T0) will install a stalled page (A) into the
PTE and cause data corruption.

One possible callstack is like this:

CPU0 CPU1
---- ----
do_swap_page() do_swap_page() with same entry
<direct swapin path> <direct swapin path>
<alloc page A> <alloc page B>
swap_read_folio() <- read to page A swap_read_folio() <- read to page B
<slow on later locks or interrupt> <finished swapin first>
... set_pte_at()
swap_free() <- entry is free
<write to page B, now page A stalled>
<swap out page B to same swap entry>
pte_same() <- Check pass, PTE seems
unchanged, but page A
is stalled!
swap_free() <- page B content lost!
set_pte_at() <- staled page A installed!

And besides, for ZRAM, swap_free() allows the swap device to discard the
entry content, so even if page (B) is not modified, if swap_read_folio()
on CPU0 happens later than swap_free() on CPU1, it may also cause data
loss.

To fix this, reuse swapcache_prepare which will pin the swap entry using
the cache flag, and allow only one thread to swap it in, also prevent any
parallel code from putting the entry in the cache. Release the pin after
PT unlocked.

Racers just loop and wait since it's a rare and very short event. A
schedule_timeout_uninterruptible(1) call is added to avoid repeated page
faults wasting too much CPU, causing livelock or adding too much noise to
perf statistics. A similar livelock issue was described in commit
029c4628b2eb ("mm: swap: get rid of livelock in swapin readahead")

Reproducer:

This race issue can be triggered easily using a well constructed
reproducer and patched brd (with a delay in read path) [1]:

With latest 6.8 mainline, race caused data loss can be observed easily:
$ gcc -g -lpthread test-thread-swap-race.c && ./a.out
Polulating 32MB of memory region...
Keep swapping out...
Starting round 0...
Spawning 65536 workers...
32746 workers spawned, wait for done...
Round 0: Error on 0x5aa00, expected 32746, got 32743, 3 data loss!
Round 0: Error on 0x395200, expected 32746, got 32743, 3 data loss!
Round 0: Error on 0x3fd000, expected 32746, got 32737, 9 data loss!
Round 0 Failed, 15 data loss!

This reproducer spawns multiple threads sharing the same memory region
using a small swap device. Every two threads updates mapped pages one by
one in opposite direction trying to create a race, with one dedicated
thread keep swapping out the data out using madvise.

The reproducer created a reproduce rate of about once every 5 minutes, so
the race should be totally possible in production.

After this patch, I ran the reproducer for over a few hundred rounds and
no data loss observed.

Performance overhead is minimal, microbenchmark swapin 10G from 32G
zram:

Before: 10934698 us
After: 11157121 us
Cached: 13155355 us (Dropping SWP_SYNCHRONOUS_IO flag)

[kasong@tencent.com: v4]
Link: https://lkml.kernel.org/r/20240219082040.7495-1-ryncsn@gmail.com

SUSE information

Overall state of this security issue: Resolved

This issue is currently rated as having moderate severity.

CVSS v3 Scores
  SUSE
Base Score 5.5
Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality Impact None
Integrity Impact None
Availability Impact High
CVSSv3 Version 3.1
SUSE Bugzilla entry: 1230340 [NEW]

No SUSE Security Announcements cross referenced.

List of released packages

Product(s) Fixed package version(s) References
SUSE Liberty Linux 8
  • bpftool >= 4.18.0-553.8.1.el8_10
  • kernel >= 4.18.0-553.8.1.el8_10
  • kernel-abi-stablelists >= 4.18.0-553.8.1.el8_10
  • kernel-core >= 4.18.0-553.8.1.el8_10
  • kernel-cross-headers >= 4.18.0-553.8.1.el8_10
  • kernel-debug >= 4.18.0-553.8.1.el8_10
  • kernel-debug-core >= 4.18.0-553.8.1.el8_10
  • kernel-debug-devel >= 4.18.0-553.8.1.el8_10
  • kernel-debug-modules >= 4.18.0-553.8.1.el8_10
  • kernel-debug-modules-extra >= 4.18.0-553.8.1.el8_10
  • kernel-devel >= 4.18.0-553.8.1.el8_10
  • kernel-doc >= 4.18.0-553.8.1.el8_10
  • kernel-headers >= 4.18.0-553.8.1.el8_10
  • kernel-modules >= 4.18.0-553.8.1.el8_10
  • kernel-modules-extra >= 4.18.0-553.8.1.el8_10
  • kernel-tools >= 4.18.0-553.8.1.el8_10
  • kernel-tools-libs >= 4.18.0-553.8.1.el8_10
  • kernel-tools-libs-devel >= 4.18.0-553.8.1.el8_10
  • perf >= 4.18.0-553.8.1.el8_10
  • python3-perf >= 4.18.0-553.8.1.el8_10
 Patchnames:
RHSA-2024:4211

Status of this issue by product and package

Please note that this evaluation state might be work in progress, incomplete or outdated. Also information for service packs in the LTSS phase is only included for issues meeting the LTSS criteria. If in doubt, feel free to contact us for clarification. The updates are grouped by state of their lifecycle. SUSE product lifecycles are documented on the lifecycle page.

Product(s) Source package State
Products under general support and receiving all security fixes.
SUSE Enterprise Storage 7.1 kernel-default Ignore
SUSE Enterprise Storage 7.1 kernel-source Ignore
SUSE Enterprise Storage 7.1 kernel-source-azure Ignore
SUSE Linux Enterprise Desktop 15 SP5 kernel-default Ignore
SUSE Linux Enterprise Desktop 15 SP5 kernel-source Ignore
SUSE Linux Enterprise High Performance Computing 12 SP5 kernel-default Ignore
SUSE Linux Enterprise High Performance Computing 12 SP5 kernel-source Ignore
SUSE Linux Enterprise High Performance Computing 12 SP5 kernel-source-azure Ignore
SUSE Linux Enterprise High Performance Computing 15 SP5 kernel-default Ignore
SUSE Linux Enterprise High Performance Computing 15 SP5 kernel-source Ignore
SUSE Linux Enterprise High Performance Computing 15 SP5 kernel-source-azure Ignore
SUSE Linux Enterprise Micro 5.1 kernel-default Ignore
SUSE Linux Enterprise Micro 5.1 kernel-rt Ignore
SUSE Linux Enterprise Micro 5.1 kernel-source-rt Ignore
SUSE Linux Enterprise Micro 5.2 kernel-default Ignore
SUSE Linux Enterprise Micro 5.2 kernel-rt Ignore
SUSE Linux Enterprise Micro 5.2 kernel-source-rt Ignore
SUSE Linux Enterprise Micro 5.3 kernel-default Ignore
SUSE Linux Enterprise Micro 5.3 kernel-rt Ignore
SUSE Linux Enterprise Micro 5.3 kernel-source-rt Ignore
SUSE Linux Enterprise Micro 5.4 kernel-default Ignore
SUSE Linux Enterprise Micro 5.4 kernel-rt Ignore
SUSE Linux Enterprise Micro 5.4 kernel-source-rt Ignore
SUSE Linux Enterprise Micro 5.5 kernel-source-rt Ignore
SUSE Linux Enterprise Micro 6.0 kernel-source Ignore
SUSE Linux Enterprise Micro 6.0 kernel-source-rt Ignore
SUSE Linux Enterprise Module for Basesystem 15 SP5 kernel-default Ignore
SUSE Linux Enterprise Module for Basesystem 15 SP5 kernel-source Ignore
SUSE Linux Enterprise Module for Development Tools 15 SP5 kernel-default Ignore
SUSE Linux Enterprise Module for Development Tools 15 SP5 kernel-source Ignore
SUSE Linux Enterprise Module for Public Cloud 15 SP5 kernel-source-azure Ignore
SUSE Linux Enterprise Real Time 12 SP5 kernel-source-rt Ignore
SUSE Linux Enterprise Real Time 15 SP5 kernel-source-rt Ignore
SUSE Linux Enterprise Server 12 SP5 kernel-default Ignore
SUSE Linux Enterprise Server 12 SP5 kernel-source Ignore
SUSE Linux Enterprise Server 12 SP5 kernel-source-azure Ignore
SUSE Linux Enterprise Server 15 SP5 kernel-default Ignore
SUSE Linux Enterprise Server 15 SP5 kernel-source Ignore
SUSE Linux Enterprise Server 15 SP5 kernel-source-azure Ignore
SUSE Linux Enterprise Server for SAP Applications 12 SP5 kernel-default Ignore
SUSE Linux Enterprise Server for SAP Applications 12 SP5 kernel-source Ignore
SUSE Linux Enterprise Server for SAP Applications 12 SP5 kernel-source-azure Ignore
SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-default Ignore
SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-source Ignore
SUSE Linux Enterprise Server for SAP Applications 15 SP5 kernel-source-azure Ignore
SUSE Manager Proxy 4.3 kernel-default Ignore
SUSE Manager Proxy 4.3 kernel-source Ignore
SUSE Manager Proxy 4.3 kernel-source-azure Ignore
SUSE Manager Retail Branch Server 4.3 kernel-default Ignore
SUSE Manager Retail Branch Server 4.3 kernel-source Ignore
SUSE Manager Retail Branch Server 4.3 kernel-source-azure Ignore
SUSE Manager Server 4.3 kernel-default Ignore
SUSE Manager Server 4.3 kernel-source Ignore
SUSE Manager Server 4.3 kernel-source-azure Ignore
SUSE Real Time Module 15 SP5 kernel-source-rt Ignore
openSUSE Leap 15.5 kernel-source Ignore
openSUSE Leap 15.5 kernel-source-azure Ignore
openSUSE Leap 15.5 kernel-source-rt Ignore
Products under Long Term Service Pack support and receiving important and critical security fixes.
SUSE Linux Enterprise Desktop 15 SP4 kernel-source Ignore
SUSE Linux Enterprise High Performance Computing 15 SP2 kernel-source Ignore
SUSE Linux Enterprise High Performance Computing 15 SP2 kernel-source-azure Ignore
SUSE Linux Enterprise High Performance Computing 15 SP2-ESPOS kernel-source Ignore
SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS kernel-default Ignore
SUSE Linux Enterprise High Performance Computing 15 SP2-LTSS kernel-source Ignore
SUSE Linux Enterprise High Performance Computing 15 SP3 kernel-source Ignore
SUSE Linux Enterprise High Performance Computing 15 SP3 kernel-source-azure Ignore
SUSE Linux Enterprise High Performance Computing 15 SP3-ESPOS kernel-source Ignore
SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-default Ignore
SUSE Linux Enterprise High Performance Computing 15 SP3-LTSS kernel-source Ignore
SUSE Linux Enterprise High Performance Computing 15 SP4 kernel-source Ignore
SUSE Linux Enterprise High Performance Computing 15 SP4 kernel-source-azure Ignore
SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS kernel-default Ignore
SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS kernel-source Ignore
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-default Ignore
SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS kernel-source Ignore
SUSE Linux Enterprise Module for Basesystem 15 SP2 kernel-source Ignore
SUSE Linux Enterprise Module for Basesystem 15 SP3 kernel-source Ignore
SUSE Linux Enterprise Module for Basesystem 15 SP4 kernel-source Ignore
SUSE Linux Enterprise Module for Development Tools 15 SP2 kernel-source Ignore
SUSE Linux Enterprise Module for Development Tools 15 SP3 kernel-source Ignore
SUSE Linux Enterprise Module for Development Tools 15 SP4 kernel-source Ignore
SUSE Linux Enterprise Module for Public Cloud 15 SP4 kernel-source-azure Ignore
SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE kernel-default Ignore
SUSE Linux Enterprise Server 11 SP4 LTSS EXTREME CORE kernel-source Ignore
SUSE Linux Enterprise Server 15 SP2 kernel-source Ignore
SUSE Linux Enterprise Server 15 SP2 kernel-source-azure Ignore
SUSE Linux Enterprise Server 15 SP2-LTSS kernel-default Ignore
SUSE Linux Enterprise Server 15 SP2-LTSS kernel-source Ignore
SUSE Linux Enterprise Server 15 SP3 kernel-source Ignore
SUSE Linux Enterprise Server 15 SP3 kernel-source-azure Ignore
SUSE Linux Enterprise Server 15 SP3-LTSS kernel-default Ignore
SUSE Linux Enterprise Server 15 SP3-LTSS kernel-source Ignore
SUSE Linux Enterprise Server 15 SP4 kernel-source Ignore
SUSE Linux Enterprise Server 15 SP4 kernel-source-azure Ignore
SUSE Linux Enterprise Server 15 SP4-LTSS kernel-default Ignore
SUSE Linux Enterprise Server 15 SP4-LTSS kernel-source Ignore
SUSE Linux Enterprise Server for SAP Applications 15 SP2 kernel-default Ignore
SUSE Linux Enterprise Server for SAP Applications 15 SP2 kernel-source Ignore
SUSE Linux Enterprise Server for SAP Applications 15 SP2 kernel-source-azure Ignore
SUSE Linux Enterprise Server for SAP Applications 15 SP3 kernel-default Ignore
SUSE Linux Enterprise Server for SAP Applications 15 SP3 kernel-source Ignore
SUSE Linux Enterprise Server for SAP Applications 15 SP3 kernel-source-azure Ignore
SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-default Ignore
SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-source Ignore
SUSE Linux Enterprise Server for SAP Applications 15 SP4 kernel-source-azure Ignore
Products past their end of life and not receiving proactive updates anymore.
HPE Helion OpenStack 8 kernel-source Ignore
SUSE CaaS Platform 4.0 kernel-source Ignore
SUSE CaaS Platform Toolchain 3 kernel-source Ignore
SUSE Enterprise Storage 6 kernel-source Ignore
SUSE Enterprise Storage 7 kernel-source Ignore
SUSE Enterprise Storage 7 kernel-source-azure Ignore
SUSE Linux Enterprise Desktop 11 SP4 kernel-source Ignore
SUSE Linux Enterprise Desktop 12 SP2 kernel-source Ignore
SUSE Linux Enterprise Desktop 12 SP3 kernel-source Ignore
SUSE Linux Enterprise Desktop 12 SP4 kernel-source Ignore
SUSE Linux Enterprise Desktop 15 kernel-source Ignore
SUSE Linux Enterprise Desktop 15 SP1 kernel-source Ignore
SUSE Linux Enterprise Desktop 15 SP2 kernel-source Ignore
SUSE Linux Enterprise Desktop 15 SP3 kernel-source Ignore
SUSE Linux Enterprise High Performance Computing 15 kernel-source Ignore
SUSE Linux Enterprise High Performance Computing 15 SP1 kernel-source Ignore
SUSE Linux Enterprise High Performance Computing 15 SP1-ESPOS kernel-source Ignore
SUSE Linux Enterprise High Performance Computing 15 SP1-LTSS kernel-source Ignore
SUSE Linux Enterprise High Performance Computing 15-ESPOS kernel-source Ignore
SUSE Linux Enterprise High Performance Computing 15-LTSS kernel-source Ignore
SUSE Linux Enterprise Micro 5.0 kernel-default Ignore
SUSE Linux Enterprise Module for Basesystem 15 kernel-source Ignore
SUSE Linux Enterprise Module for Basesystem 15 SP1 kernel-source Ignore
SUSE Linux Enterprise Module for Development Tools 15 kernel-source Ignore
SUSE Linux Enterprise Module for Development Tools 15 SP1 kernel-source Ignore
SUSE Linux Enterprise Module for Public Cloud 15 SP2 kernel-source-azure Ignore
SUSE Linux Enterprise Module for Public Cloud 15 SP3 kernel-source-azure Ignore
SUSE Linux Enterprise Point of Sale 12 SP2-CLIENT kernel-source Ignore
SUSE Linux Enterprise Real Time 15 SP2 kernel-source Ignore
SUSE Linux Enterprise Real Time 15 SP3 kernel-source Ignore
SUSE Linux Enterprise Real Time 15 SP3 kernel-source-rt Ignore
SUSE Linux Enterprise Real Time 15 SP4 kernel-source Ignore
SUSE Linux Enterprise Real Time 15 SP4 kernel-source-rt Ignore
SUSE Linux Enterprise Server 11 SP4 kernel-source Ignore
SUSE Linux Enterprise Server 11 SP4 LTSS kernel-default Ignore
SUSE Linux Enterprise Server 11 SP4 LTSS kernel-source Ignore
SUSE Linux Enterprise Server 11 SP4-LTSS kernel-source Ignore
SUSE Linux Enterprise Server 12 SP2 kernel-source Ignore
SUSE Linux Enterprise Server 12 SP2-BCL kernel-source Ignore
SUSE Linux Enterprise Server 12 SP2-ESPOS kernel-source Ignore
SUSE Linux Enterprise Server 12 SP2-LTSS kernel-source Ignore
SUSE Linux Enterprise Server 12 SP3 kernel-source Ignore
SUSE Linux Enterprise Server 12 SP3-BCL kernel-source Ignore
SUSE Linux Enterprise Server 12 SP3-ESPOS kernel-source Ignore
SUSE Linux Enterprise Server 12 SP3-LTSS kernel-source Ignore
SUSE Linux Enterprise Server 12 SP4 kernel-source Ignore
SUSE Linux Enterprise Server 12 SP4-ESPOS kernel-source Ignore
SUSE Linux Enterprise Server 12 SP4-LTSS kernel-default Ignore
SUSE Linux Enterprise Server 12 SP4-LTSS kernel-source Ignore
SUSE Linux Enterprise Server 15 kernel-source Ignore
SUSE Linux Enterprise Server 15 SP1 kernel-source Ignore
SUSE Linux Enterprise Server 15 SP1-BCL kernel-source Ignore
SUSE Linux Enterprise Server 15 SP1-LTSS kernel-default Ignore
SUSE Linux Enterprise Server 15 SP1-LTSS kernel-source Ignore
SUSE Linux Enterprise Server 15 SP2-BCL kernel-source Ignore
SUSE Linux Enterprise Server 15 SP3-BCL kernel-source Ignore
SUSE Linux Enterprise Server 15-LTSS kernel-default Ignore
SUSE Linux Enterprise Server 15-LTSS kernel-source Ignore
SUSE Linux Enterprise Server for Raspberry Pi 12 SP2 kernel-source Ignore
SUSE Linux Enterprise Server for SAP Applications 12 SP2 kernel-source Ignore
SUSE Linux Enterprise Server for SAP Applications 12 SP3 kernel-source Ignore
SUSE Linux Enterprise Server for SAP Applications 12 SP4 kernel-default Ignore
SUSE Linux Enterprise Server for SAP Applications 12 SP4 kernel-source Ignore
SUSE Linux Enterprise Server for SAP Applications 15 kernel-source Ignore
SUSE Linux Enterprise Server for SAP Applications 15 SP1 kernel-source Ignore
SUSE Manager Proxy 4.0 kernel-source Ignore
SUSE Manager Proxy 4.1 kernel-source Ignore
SUSE Manager Proxy 4.1 kernel-source-azure Ignore
SUSE Manager Proxy 4.2 kernel-source Ignore
SUSE Manager Proxy 4.2 kernel-source-azure Ignore
SUSE Manager Retail Branch Server 4.0 kernel-source Ignore
SUSE Manager Retail Branch Server 4.1 kernel-source Ignore
SUSE Manager Retail Branch Server 4.1 kernel-source-azure Ignore
SUSE Manager Retail Branch Server 4.2 kernel-source Ignore
SUSE Manager Retail Branch Server 4.2 kernel-source-azure Ignore
SUSE Manager Server 4.0 kernel-source Ignore
SUSE Manager Server 4.1 kernel-source Ignore
SUSE Manager Server 4.1 kernel-source-azure Ignore
SUSE Manager Server 4.2 kernel-source Ignore
SUSE Manager Server 4.2 kernel-source-azure Ignore
SUSE OpenStack Cloud 7 kernel-source Ignore
SUSE OpenStack Cloud 8 kernel-source Ignore
SUSE OpenStack Cloud 9 kernel-default Ignore
SUSE OpenStack Cloud 9 kernel-source Ignore
SUSE OpenStack Cloud Crowbar 8 kernel-source Ignore
SUSE OpenStack Cloud Crowbar 9 kernel-default Ignore
SUSE OpenStack Cloud Crowbar 9 kernel-source Ignore
SUSE Real Time Module 15 SP3 kernel-source-rt Ignore
SUSE Real Time Module 15 SP4 kernel-source-rt Ignore
openSUSE Leap 15.3 kernel-source Ignore
openSUSE Leap 15.3 kernel-source-azure Ignore
openSUSE Leap 15.3 kernel-source-rt Ignore
openSUSE Leap 15.4 kernel-source Ignore
openSUSE Leap 15.4 kernel-source-azure Ignore
openSUSE Leap 15.4 kernel-source-rt Ignore

SUSE Timeline for this CVE

CVE page created: Wed Apr 3 20:01:06 2024
CVE page last modified: Tue Sep 10 12:00:54 2024