CVE-2021-47419
CVE-2021-47419CVE-2021-47419
linux / linux_kernel
Description
In the Linux kernel, the following vulnerability has been resolved:
net/sched: sch_taprio: properly cancel timer from taprio_destroy()
There is a comment in qdisc_create() about us not calling ops->reset()
in some cases.
err_out4:
/*
* Any broken qdiscs that would require a ops->reset() here?
* The qdisc was never in action so it shouldn't be necessary.
*/
As taprio sets a timer before actually receiving a packet, we need
to cancel it from ops->destroy, just in case ops->reset has not
been called.
syzbot reported:
ODEBUG: free active (active state 0) object type: hrtimer hint: advance_sched+0x0/0x9a0 arch/x86/include/asm/atomic64_64.h:22
WARNING: CPU: 0 PID: 8441 at lib/debugobjects.c:505 debug_print_object+0x16e/0x250 lib/debugobjects.c:505
Modules linked in:
CPU: 0 PID: 8441 Comm: syz-executor813 Not tainted 5.14.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:debug_print_object+0x16e/0x250 lib/debugo
Scoring
| CVSS | 7.8 () |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
| Last modified | 2026-08-04 |