CVE-2022-50697
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.
EPSS (Exploit Prediction Scoring System)
EPSS (Exploit Prediction Scoring System)
Prevede la probabilità di sfruttamento basata su intelligence sulle minacce e sulle caratteristiche della vulnerabilità.