Upstream information

CVE-2021-46957 at MITRE

Description

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

riscv/kprobe: fix kernel panic when invoking sys_read traced by kprobe

The execution of sys_read end up hitting a BUG_ON() in __find_get_block
after installing kprobe at sys_read, the BUG message like the following:

[ 65.708663] ------------[ cut here ]------------
[ 65.709987] kernel BUG at fs/buffer.c:1251!
[ 65.711283] Kernel BUG [#1]
[ 65.712032] Modules linked in:
[ 65.712925] CPU: 0 PID: 51 Comm: sh Not tainted 5.12.0-rc4 #1
[ 65.714407] Hardware name: riscv-virtio,qemu (DT)
[ 65.715696] epc : __find_get_block+0x218/0x2c8
[ 65.716835] ra : __getblk_gfp+0x1c/0x4a
[ 65.717831] epc : ffffffe00019f11e ra : ffffffe00019f56a sp : ffffffe002437930
[ 65.719553] gp : ffffffe000f06030 tp : ffffffe0015abc00 t0 : ffffffe00191e038
[ 65.721290] t1 : ffffffe00191e038 t2 : 000000000000000a s0 : ffffffe002437960
[ 65.723051] s1 : ffffffe00160ad00 a0 : ffffffe00160ad00 a1 : 000000000000012a
[ 65.724772] a2 : 0000000000000400 a3 : 0000000000000008 a4 : 0000000000000040
[ 65.726545] a5 : 0000000000000000 a6 : ffffffe00191e000 a7 : 0000000000000000
[ 65.728308] s2 : 000000000000012a s3 : 0000000000000400 s4 : 0000000000000008
[ 65.730049] s5 : 000000000000006c s6 : ffffffe00240f800 s7 : ffffffe000f080a8
[ 65.731802] s8 : 0000000000000001 s9 : 000000000000012a s10: 0000000000000008
[ 65.733516] s11: 0000000000000008 t3 : 00000000000003ff t4 : 000000000000000f
[ 65.734434] t5 : 00000000000003ff t6 : 0000000000040000
[ 65.734613] status: 0000000000000100 badaddr: 0000000000000000 cause: 0000000000000003
[ 65.734901] Call Trace:
[ 65.735076] [<ffffffe00019f11e>] __find_get_block+0x218/0x2c8
[ 65.735417] [<ffffffe00020017a>] __ext4_get_inode_loc+0xb2/0x2f6
[ 65.735618] [<ffffffe000201b6c>] ext4_get_inode_loc+0x3a/0x8a
[ 65.735802] [<ffffffe000203380>] ext4_reserve_inode_write+0x2e/0x8c
[ 65.735999] [<ffffffe00020357a>] __ext4_mark_inode_dirty+0x4c/0x18e
[ 65.736208] [<ffffffe000206bb0>] ext4_dirty_inode+0x46/0x66
[ 65.736387] [<ffffffe000192914>] __mark_inode_dirty+0x12c/0x3da
[ 65.736576] [<ffffffe000180dd2>] touch_atime+0x146/0x150
[ 65.736748] [<ffffffe00010d762>] filemap_read+0x234/0x246
[ 65.736920] [<ffffffe00010d834>] generic_file_read_iter+0xc0/0x114
[ 65.737114] [<ffffffe0001f5d7a>] ext4_file_read_iter+0x42/0xea
[ 65.737310] [<ffffffe000163f2c>] new_sync_read+0xe2/0x15a
[ 65.737483] [<ffffffe000165814>] vfs_read+0xca/0xf2
[ 65.737641] [<ffffffe000165bae>] ksys_read+0x5e/0xc8
[ 65.737816] [<ffffffe000165c26>] sys_read+0xe/0x16
[ 65.737973] [<ffffffe000003972>] ret_from_syscall+0x0/0x2
[ 65.738858] ---[ end trace fe93f985456c935d ]---

A simple reproducer looks like:
echo 'p:myprobe sys_read fd=%a0 buf=%a1 count=%a2' > /sys/kernel/debug/tracing/kprobe_events
echo 1 > /sys/kernel/debug/tracing/events/kprobes/myprobe/enable
cat /sys/kernel/debug/tracing/trace

Here's what happens to hit that BUG_ON():

1) After installing kprobe at entry of sys_read, the first instruction
is replaced by 'ebreak' instruction on riscv64 platform.

2) Once kernel reach the 'ebreak' instruction at the entry of sys_read,
it trap into the riscv breakpoint handler, where it do something to
setup for coming single-step of origin instruction, including backup
the 'sstatus' in pt_regs, followed by disable interrupt during single
stepping via clear 'SIE' bit of 'sstatus' in pt_regs.

3) Then kernel restore to the instruction slot contains two instructions,
one is original instruction at entry of sys_read, the other is 'ebreak'.
Here it trigger a 'Instruction page fault' exception (value at 'scause'
is '0xc'), if PF is not filled into PageTabe for that slot yet.

4) Again kernel trap into page fault exception handler, where it choose
different policy according to the state of running kprobe. Because
afte 2) the state is KPROBE_HIT_SS, so kernel reset the current kp
---truncated---

SUSE information

Overall state of this security issue: Resolved

This issue is currently rated as having moderate severity.

CVSS v3 Scores
  CNA (CISA-ADP)
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: 1220518 [RESOLVED / FIXED]

No SUSE Security Announcements cross referenced.


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


SUSE Timeline for this CVE

CVE page created: Tue Feb 27 21:06:20 2024
CVE page last modified: Sun Nov 3 00:42:05 2024