Riskcovery

CVE-2022-50697

mrp: introduce active flags to prevent UAF when applicant uninit

State
Published
Severity
7.8 High
Published
Dec 24, 2025
Updated
Oct 15, 2026
Reserved
Dec 24, 2025

Read the record on cve.org

Description

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

mrp: introduce active flags to prevent UAF when applicant uninit

The caller of del_timer_sync must prevent restarting of the timer, If we have no this synchronization, there is a small probability that the cancellation will not be successful.

And syzbot report the fellowing crash: ================================================================== BUG: KASAN: use-after-free in hlist_add_head include/linux/list.h:929 [inline] BUG: KASAN: use-after-free in enqueue_timer+0x18/0xa4 kernel/time/timer.c:605 Write at addr f9ff000024df6058 by task syz-fuzzer/2256 Pointer tag: [f9], memory tag: [fe]

CPU: 1 PID: 2256 Comm: syz-fuzzer Not tainted 6.1.0-rc5-syzkaller-00008- ge01d50cbd6ee #0 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace.part.0+0xe0/0xf0 arch/arm64/kernel/stacktrace.c:156 dump_backtrace arch/arm64/kernel/stacktrace.c:162 [inline] show_stack+0x18/0x40 arch/arm64/kernel/stacktrace.c:163 __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x68/0x84 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:284 [inline] print_report+0x1a8/0x4a0 mm/kasan/report.c:395 kasan_report+0x94/0xb4 mm/kasan/report.c:495 __do_kernel_fault+0x164/0x1e0 arch/arm64/mm/fault.c:320 do_bad_area arch/arm64/mm/fault.c:473 [inline] do_tag_check_fault+0x78/0x8c arch/arm64/mm/fault.c:749 do_mem_abort+0x44/0x94 arch/arm64/mm/fault.c:825 el1_abort+0x40/0x60 arch/arm64/kernel/entry-common.c:367 el1h_64_sync_handler+0xd8/0xe4 arch/arm64/kernel/entry-common.c:427 el1h_64_sync+0x64/0x68 arch/arm64/kernel/entry.S:576 hlist_add_head include/linux/list.h:929 [inline] enqueue_timer+0x18/0xa4 kernel/time/timer.c:605 mod_timer+0x14/0x20 kernel/time/timer.c:1161 mrp_periodic_timer_arm net/802/mrp.c:614 [inline] mrp_periodic_timer+0xa0/0xc0 net/802/mrp.c:627 call_timer_fn.constprop.0+0x24/0x80 kernel/time/timer.c:1474 expire_timers+0x98/0xc4 kernel/time/timer.c:1519

To fix it, we can introduce a new active flags to make sure the timer will not restart.

Scores

CVSSScoreVectorSource
3.17.8 HighCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HLinux

Weaknesses

The record names no weakness.

Affected Products

ProductVersions
LinuxLinux
  • febf018d22347b5df94066bca05d0c11a84e839d to before 98f53e591940e4c3818be358c5dc684d5b30cb56Affected
  • febf018d22347b5df94066bca05d0c11a84e839d to before aacffc1a8dbf67c5463cb4f67b37143c01ca6fa9Affected
  • febf018d22347b5df94066bca05d0c11a84e839d to before 78d48bc41f7726113c9f114268d3ab11212814daAffected
  • febf018d22347b5df94066bca05d0c11a84e839d to before aadb1507a77b060c529edfeaf67f803e31461f24Affected
  • febf018d22347b5df94066bca05d0c11a84e839d to before 755eb0879224ffc2a43de724554aeaf0e51e5a64Affected
  • febf018d22347b5df94066bca05d0c11a84e839d to before 5d5a481a7fd0234f617535dc464ea010804a1129Affected
  • febf018d22347b5df94066bca05d0c11a84e839d to before 1a185fe83c2a60c1e3596fb9d82dbeb148dc09c6Affected
  • febf018d22347b5df94066bca05d0c11a84e839d to before 563e45fd5046045cc194af3ba17f5423e1c98170Affected
  • febf018d22347b5df94066bca05d0c11a84e839d to before ab0377803dafc58f1e22296708c1c28e309414d6Affected
LinuxLinux
  • 3.9Affected
  • before 3.9Not affected
  • 4.9.337 through 4.9.*Not affected
  • 4.14.303 through 4.14.*Not affected
  • 4.19.270 through 4.19.*Not affected
  • 5.4.229 through 5.4.*Not affected
  • 5.10.163 through 5.10.*Not affected
  • 5.15.86 through 5.15.*Not affected
  • 6.0.16 through 6.0.*Not affected
  • 6.1.2 through 6.1.*Not affected
  • 6.2 and laterNot affected

References

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