CVE-2021-47346 coresight: tmc-etf: Fix global-out-of-bounds in tmc_update_etf_buffer()

2024-05-2114:35:52

Linux

github.com

linux kernel

vulnerability

coresight

tmc-etf

global-out-of-bounds

kasan

bug

security

6.8 Medium

AI Score

Confidence

Low

0.0004 Low

EPSS

Percentile

10.3%

JSON

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

coresight: tmc-etf: Fix global-out-of-bounds in tmc_update_etf_buffer()

commit 6f755e85c332 (“coresight: Add helper for inserting synchronization
packets”) removed trailing ‘\0’ from barrier_pkt array and updated the
call sites like etb_update_buffer() to have proper checks for barrier_pkt
size before read but missed updating tmc_update_etf_buffer() which still
reads barrier_pkt past the array size resulting in KASAN out-of-bounds
bug. Fix this by adding a check for barrier_pkt size before accessing
like it is done in etb_update_buffer().

BUG: KASAN: global-out-of-bounds in tmc_update_etf_buffer+0x4b8/0x698
Read of size 4 at addr ffffffd05b7d1030 by task perf/2629

Call trace:
dump_backtrace+0x0/0x27c
show_stack+0x20/0x2c
dump_stack+0x11c/0x188
print_address_description+0x3c/0x4a4
__kasan_report+0x140/0x164
kasan_report+0x10/0x18
__asan_report_load4_noabort+0x1c/0x24
tmc_update_etf_buffer+0x4b8/0x698
etm_event_stop+0x248/0x2d8
etm_event_del+0x20/0x2c
event_sched_out+0x214/0x6f0
group_sched_out+0xd0/0x270
ctx_sched_out+0x2ec/0x518
__perf_event_task_sched_out+0x4fc/0xe6c
__schedule+0x1094/0x16a0
preempt_schedule_irq+0x88/0x170
arm64_preempt_schedule_irq+0xf0/0x18c
el1_irq+0xe8/0x180
perf_event_exec+0x4d8/0x56c
setup_new_exec+0x204/0x400
load_elf_binary+0x72c/0x18c0
search_binary_handler+0x13c/0x420
load_script+0x500/0x6c4
search_binary_handler+0x13c/0x420
exec_binprm+0x118/0x654
__do_execve_file+0x77c/0xba4
__arm64_compat_sys_execve+0x98/0xac
el0_svc_common+0x1f8/0x5e0
el0_svc_compat_handler+0x84/0xb0
el0_svc_compat+0x10/0x50

The buggy address belongs to the variable:
barrier_pkt+0x10/0x40

Memory state around the buggy address:
ffffffd05b7d0f00: fa fa fa fa 04 fa fa fa fa fa fa fa 00 00 00 00
ffffffd05b7d0f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffffd05b7d1000: 00 00 00 00 00 00 fa fa fa fa fa fa 00 00 00 03
^
ffffffd05b7d1080: fa fa fa fa 00 02 fa fa fa fa fa fa 03 fa fa fa
ffffffd05b7d1100: fa fa fa fa 00 00 00 00 05 fa fa fa fa fa fa fa

CNA Affected

[
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "unaffected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/hwtracing/coresight/coresight-tmc-etf.c"
    ],
    "versions": [
      {
        "version": "0c3fc4d5fa26",
        "lessThan": "04bd77ef4f4d",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "0c3fc4d5fa26",
        "lessThan": "ef0a06acc6b1",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "0c3fc4d5fa26",
        "lessThan": "35c1c4bd2d59",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "0c3fc4d5fa26",
        "lessThan": "733d4d95c010",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "0c3fc4d5fa26",
        "lessThan": "0115687be7b1",
        "status": "affected",
        "versionType": "git"
      },
      {
        "version": "0c3fc4d5fa26",
        "lessThan": "5fae8a946ac2",
        "status": "affected",
        "versionType": "git"
      }
    ]
  },
  {
    "product": "Linux",
    "vendor": "Linux",
    "defaultStatus": "affected",
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "programFiles": [
      "drivers/hwtracing/coresight/coresight-tmc-etf.c"
    ],
    "versions": [
      {
        "version": "4.14",
        "status": "affected"
      },
      {
        "version": "0",
        "lessThan": "4.14",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "4.19.198",
        "lessThanOrEqual": "4.19.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.4.133",
        "lessThanOrEqual": "5.4.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.10.51",
        "lessThanOrEqual": "5.10.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.12.18",
        "lessThanOrEqual": "5.12.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.13.3",
        "lessThanOrEqual": "5.13.*",
        "status": "unaffected",
        "versionType": "custom"
      },
      {
        "version": "5.14",
        "lessThanOrEqual": "*",
        "status": "unaffected",
        "versionType": "original_commit_for_fix"
      }
    ]
  }
]