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

net: hamradio: fix memory leak in mkiss_close

My local syzbot instance hit memory leak in
mkiss_open()[1]. The problem was in missing
free_netdev() in mkiss_close().

In mkiss_open() netdevice is allocated and then
registered, but in mkiss_close() netdevice was
only unregistered, but not freed.

Fail log:

BUG: memory leak
unreferenced object 0xffff8880281ba000 (size 4096):
comm "syz-executor.1", pid 11443, jiffies 4295046091 (age 17.660s)
hex dump (first 32 bytes):
61 78 30 00 00 00 00 00 00 00 00 00 00 00 00 00 ax0.............
00 27 fa 2a 80 88 ff ff 00 00 00 00 00 00 00 00 .'.*............
backtrace:
[<ffffffff81a27201>] kvmalloc_node+0x61/0xf0
[<ffffffff8706e7e8>] alloc_netdev_mqs+0x98/0xe80
[<ffffffff84e64192>] mkiss_open+0xb2/0x6f0 [1]
[<ffffffff842355db>] tty_ldisc_open+0x9b/0x110
[<ffffffff84236488>] tty_set_ldisc+0x2e8/0x670
[<ffffffff8421f7f3>] tty_ioctl+0xda3/0x1440
[<ffffffff81c9f273>] __x64_sys_ioctl+0x193/0x200
[<ffffffff8911263a>] do_syscall_64+0x3a/0xb0
[<ffffffff89200068>] entry_SYSCALL_64_after_hwframe+0x44/0xae

BUG: memory leak
unreferenced object 0xffff8880141a9a00 (size 96):
comm "syz-executor.1", pid 11443, jiffies 4295046091 (age 17.660s)
hex dump (first 32 bytes):
e8 a2 1b 28 80 88 ff ff e8 a2 1b 28 80 88 ff ff ...(.......(....
98 92 9c aa b0 40 02 00 00 00 00 00 00 00 00 00 .....@..........
backtrace:
[<ffffffff8709f68b>] __hw_addr_create_ex+0x5b/0x310
[<ffffffff8709fb38>] __hw_addr_add_ex+0x1f8/0x2b0
[<ffffffff870a0c7b>] dev_addr_init+0x10b/0x1f0
[<ffffffff8706e88b>] alloc_netdev_mqs+0x13b/0xe80
[<ffffffff84e64192>] mkiss_open+0xb2/0x6f0 [1]
[<ffffffff842355db>] tty_ldisc_open+0x9b/0x110
[<ffffffff84236488>] tty_set_ldisc+0x2e8/0x670
[<ffffffff8421f7f3>] tty_ioctl+0xda3/0x1440
[<ffffffff81c9f273>] __x64_sys_ioctl+0x193/0x200
[<ffffffff8911263a>] do_syscall_64+0x3a/0xb0
[<ffffffff89200068>] entry_SYSCALL_64_after_hwframe+0x44/0xae

BUG: memory leak
unreferenced object 0xffff8880219bfc00 (size 512):
comm "syz-executor.1", pid 11443, jiffies 4295046091 (age 17.660s)
hex dump (first 32 bytes):
00 a0 1b 28 80 88 ff ff 80 8f b1 8d ff ff ff ff ...(............
80 8f b1 8d ff ff ff ff 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff81a27201>] kvmalloc_node+0x61/0xf0
[<ffffffff8706eec7>] alloc_netdev_mqs+0x777/0xe80
[<ffffffff84e64192>] mkiss_open+0xb2/0x6f0 [1]
[<ffffffff842355db>] tty_ldisc_open+0x9b/0x110
[<ffffffff84236488>] tty_set_ldisc+0x2e8/0x670
[<ffffffff8421f7f3>] tty_ioctl+0xda3/0x1440
[<ffffffff81c9f273>] __x64_sys_ioctl+0x193/0x200
[<ffffffff8911263a>] do_syscall_64+0x3a/0xb0
[<ffffffff89200068>] entry_SYSCALL_64_after_hwframe+0x44/0xae

BUG: memory leak
unreferenced object 0xffff888029b2b200 (size 256):
comm "syz-executor.1", pid 11443, jiffies 4295046091 (age 17.660s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<ffffffff81a27201>] kvmalloc_node+0x61/0xf0
[<ffffffff8706f062>] alloc_netdev_mqs+0x912/0xe80
[<ffffffff84e64192>] mkiss_open+0xb2/0x6f0 [1]
[<ffffffff842355db>] tty_ldisc_open+0x9b/0x110
[<ffffffff84236488>] tty_set_ldisc+0x2e8/0x670
[<ffffffff8421f7f3>] tty_ioctl+0xda3/0x1440
[<ffffffff81c9f273>] __x64_sys_ioctl+0x193/0x200
[<ffffffff8911263a>] do_syscall_64+0x3a/0xb0
[<ffffffff89200068>] entry_SYSCALL_64_after_hwframe+0x44/0xae
Published: 2024-05-21
Score: 5.5 Medium
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

History

Mon, 30 Dec 2024 19:30:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses CWE-401
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc4:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc5:*:*:*:*:*:*
cpe:2.3:o:linux:linux_kernel:5.13:rc6:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Metrics cvssV3_1

{'score': 5.1, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:L'}

 cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

Mon, 04 Nov 2024 12:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Wed, 11 Sep 2024 18:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Wed, 11 Sep 2024 13:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-05-11T13:50:36.850Z

Reserved: 2024-04-10T18:59:19.531Z

Link: CVE-2021-47237

cve-icon Vulnrichment

Updated: 2024-08-04T05:32:07.921Z

cve-icon NVD

Status : Analyzed

Published: 2024-05-21T15:15:12.930

Modified: 2024-12-30T19:05:28.320

Link: CVE-2021-47237

cve-icon Redhat

Severity : Low

Publid Date: 2024-05-21T00:00:00Z

Links: CVE-2021-47237 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses