Bug 1224921 (CVE-2021-47346)

Summary: VUL-0: CVE-2021-47346: kernel: coresight: tmc-etf: Fix global-out-of-bounds in tmc_update_etf_buffer()
Product: [Novell Products] SUSE Security Incidents Reporter: SMASH SMASH <smash_bz>
Component: IncidentsAssignee: Security Team bot <security-team>
Status: RESOLVED INVALID QA Contact: Security Team bot <security-team>
Severity: Minor    
Priority: P3 - Medium CC: carlos.lopez, mhocko
Version: unspecified   
Target Milestone: ---   
Hardware: Other   
OS: Other   
URL: https://smash.suse.de/issue/406983/
Whiteboard: CVSSv3.1:SUSE:CVE-2021-47346:3.4:(AV:L/AC:L/PR:H/UI:N/S:U/C:L/I:N/A:L)
Found By: Security Response Team Services Priority:
Business Priority: Blocker: ---
Marketing QA Status: --- IT Deployment: ---

Description SMASH SMASH 2024-05-22 11:22:15 UTC
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
 ==================================================================

References:
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2021-47346
https://www.cve.org/CVERecord?id=CVE-2021-47346
https://git.kernel.org/stable/c/0115687be7b13993066aef602253a53d55f5b11f
https://git.kernel.org/stable/c/04bd77ef4f4d9fc6102023b85f4590fc2130aac5
https://git.kernel.org/stable/c/35c1c4bd2d59ad734129d4e232af9d1098023918
https://git.kernel.org/stable/c/5fae8a946ac2df879caf3f79a193d4766d00239b
https://git.kernel.org/stable/c/733d4d95c0101d5f277b8e4910411d016e49a9dc
https://git.kernel.org/stable/c/ef0a06acc6b16388640ad367eedfa2a17f1945db
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2021/CVE-2021-47346.mbox
Comment 2 Michal Hocko 2024-05-24 12:51:57 UTC
nothing to be done
Comment 3 Carlos López 2024-05-28 11:24:43 UTC
Nothing to do, closing.