# CVE-2021-47598: linux: In the Linux kernel, the following vulnerability has been resolved:  sch_cake: do not call cake_destroy() from cake_i...

CVE-2021-47598 is fixed in linux on 1 platform, first by DEBIAN-CVE-2021-47598, released June 19, 2024. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2021-47598
- Priority: High
- CVSS: 7.8 (high)
- EPSS: 0.0026
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Jun 19, 2024

## Description

In the Linux kernel, the following vulnerability has been resolved:  sch_cake: do not call cake_destroy() from cake_init()  qdiscs are not supposed to call their own destroy() method from init(), because core stack already does that.  syzbot was able to trigger use after free:  DEBUG_LOCKS_WARN_ON(lock->magic != lock) WARNING: CPU: 0 PID: 21902 at kernel/locking/mutex.c:586 __mutex_lock_common kernel/locking/mutex.c:586 [inline] WARNING: CPU: 0 PID: 21902 at kernel/locking/mutex.c:586 __mutex_lock+0x9ec/0x12f0 kernel/locking/mutex.c:740 Modules linked in: CPU: 0 PID: 21902 Comm: syz-executor189 Not tainted 5.16.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__mutex_lock_common kernel/locking/mutex.c:586 [inline] RIP: 0010:__mutex_lock+0x9ec/0x12f0 kernel/locking/mutex.c:740 Code: 08 84 d2 0f 85 19 08 00 00 8b 05 97 38 4b 04 85 c0 0f 85 27 f7 ff ff 48 c7 c6 20 00 ac 89 48 c7 c7 a0 fe ab 89 e8 bf 76 ba ff <0f> 0b e9 0d f7 ff ff 48 8b 44 24 40 48 8d b8 c8 08 00 00 48 89 f8 RSP: 0018:ffffc9000627f290 EFLAGS: 00010282 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 RDX: ffff88802315d700 RSI: ffffffff815f1db8 RDI: fffff52000c4fe44 RBP: ffff88818f28e000 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffff815ebb5e R11: 0000000000000000 R12: 0000000000000000 R13: dffffc0000000000 R14: ffffc9000627f458 R15: 0000000093c30000 FS:  0000555556abc400(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fda689c3303 CR3: 000000001cfbb000 CR4: 0000000000350ef0 Call Trace:  <TASK>  tcf_chain0_head_change_cb_del+0x2e/0x3d0 net/sched/cls_api.c:810  tcf_block_put_ext net/sched/cls_api.c:1381 [inline]  tcf_block_put_ext net/sched/cls_api.c:1376 [inline]  tcf_block_put+0xbc/0x130 net/sched/cls_api.c:1394  cake_destroy+0x3f/0x80 net/sched/sch_cake.c:2695  qdisc_create.constprop.0+0x9da/0x10f0 net/sched/sch_api.c:1293  tc_modify_qdisc+0x4c5/0x1980 net/sched/sch_api.c:1660  rtnetlink_rcv_msg+0x413/0xb80 net/core/rtnetlink.c:5571  netlink_rcv_skb+0x153/0x420 net/netlink/af_netlink.c:2496  netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]  netlink_unicast+0x533/0x7d0 net/netlink/af_netlink.c:1345  netlink_sendmsg+0x904/0xdf0 net/netlink/af_netlink.c:1921  sock_sendmsg_nosec net/socket.c:704 [inline]  sock_sendmsg+0xcf/0x120 net/socket.c:724  ____sys_sendmsg+0x6e8/0x810 net/socket.c:2409  ___sys_sendmsg+0xf3/0x170 net/socket.c:2463  __sys_sendmsg+0xe5/0x1b0 net/socket.c:2492  do_syscall_x64 arch/x86/entry/common.c:50 [inline]  do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80  entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f1bb06badb9 Code: Unable to access opcode bytes at RIP 0x7f1bb06bad8f. RSP: 002b:00007fff3012a658 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007f1bb06badb9 RDX: 0000000000000000 RSI: 00000000200007c0 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000003 R10: 0000000000000003 R11: 0000000000000246 R12: 00007fff3012a688 R13: 00007fff3012a6a0 R14: 00007fff3012a6e0 R15: 00000000000013c2  </TASK>

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 5.15.15-1 | [DEBIAN-CVE-2021-47598](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47598.md) | Jun 19, 2024 |
| Linux | linux Debian 13.5 (trixie) | 5.15.15-1 | [DEBIAN-CVE-2021-47598](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47598.md) | Jun 19, 2024 |
| Linux | linux Debian 14 | 5.15.15-1 | [DEBIAN-CVE-2021-47598](https://patchblox.com/security/data/fix/linux/debian-cve-2021-47598.md) | Jun 19, 2024 |

---

Data as of 2026-11-08T13:06:02Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

Free to use with attribution: show "Data: Patchblox Patch Radar" with a link to https://patchblox.com/security/patch-radar. Terms, including what needs a written agreement: https://patchblox.com/security/patch-radar/use-the-data

Product names, logos and trademarks shown on Patch Radar belong to their respective owners. They are used only to identify the software each security fix applies to and to help readers find their platform. Their use does not imply any affiliation with, or endorsement by, those owners, and Patchblox is not affiliated with any of them.