CVE-2022-50259 [Medium] | Information Disclosure in Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: bpf, sockmap: fix race in sock_map_free() sock_map_free() calls release_sock(sk) without owning a reference on the socket. This can cause use-after-free as syzbot found [1] Jakub Sitnicki already took care of a similar issue in sock_hash_free() in commit 75e68e5bf2c7 ("bpf, sockhash: Synchronize delete from bucket list on map free") [1] refcount_t: decrement hit 0; leaking memory. WARNING: CPU: 0 PID: 3785 at lib/refcount.c:31 refcount_warn_saturate+0x17c/0x1a0 lib/refcount.c:31 Modules linked in: CPU: 0 PID: 3785 Comm: kworker/u4:6 Not tainted 6.1.0-rc7-syzkaller-00103-gef4d3ea40565 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022 Workqueue: events_unbound bpf_map_free_deferred RIP: 0010:refcount_warn_saturate+0x17c/0x1a0 lib/refcount.c:31 Code: 68 8b 31 c0 e8 75 71 15 fd 0f 0b e9 64 ff ff ff e8 d9 6e 4e fd c6 05 62 9c 3d 0a 01 48 c7 c7 80 bb 68 8b 31 c0 e8 54 71 15 fd <0f> 0b e9 43 ff ff ff 89 d9 80 e1 07 80 c1 03 38 c1 0f 8c a2 fe ff RSP: 0018:ffffc9000456fb60 EFLAGS: 00010246 RAX: eae59bab72dcd700 RBX: 0000000000000004 RCX: ffff8880207057c0 RDX: 0000000000000000 RSI: 0000000000000201 RDI: 0000000000000000 RBP: 0000000000000004 R08: ffffffff816fdabd R09: fffff520008adee5 R10: fffff520008adee5 R11: 1ffff920008adee4 R12: 0000000000000004 R13: dffffc0000000000 R14: ffff88807b1c6c00 R15: 1ffff1100f638dcf FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30c30000 CR3: 000000000d08e000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: <TASK> __refcount_dec include/linux/refcount.h:344 [inline] refcount_dec include/linux/refcount.h:359 [inline] __sock_put include/net/sock.h:779 [inline] tcp_release_cb+0x2d0/0x360 net/ipv4/tcp_output.c:1092 release_sock+0xaf/0x1c0 net/core/sock.c:3468 sock_map_free+0x219/0x2c0 net/core/sock_map.c:356 process_one_work+0x81c/0xd10 kernel/workqueue.c:2289 worker_thread+0xb14/0x1330 kernel/workqueue.c:2436 kthread+0x266/0x300 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306 </TASK>

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2025-09-16	—	0.02%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2025-09-16

—

0.02%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
4.7	3.1	MEDIUM	`CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:H) Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:N) Doesn’t really leak secrets in a meaningful way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.0	3.6	[email protected]

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

4.7

3.1

MEDIUM

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H): Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N): Doesn’t really leak secrets in a meaningful way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.0

3.6

[email protected]

OS Trackers for CVE-2022-50259

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2022-50259 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5.	https://security-tracker.debian.org/tracker/CVE-2022-50259
`redhat`	low	—	https://access.redhat.com/security/cve/CVE-2022-50259
`suse`	medium	CVE-2022-50259 severity moderate: SUSE including 25 source package names (cluster-md-kmp-default, dlm-kmp-default, …), 144 product×package rows across 30 product lines (SUSE Linux Enterprise High Availability Extension 15 SP7, SUSE Linux Enterprise Live Patching 12 SP5, … (30 product lines)): Known Not Affected 144.	https://www.suse.com/security/cve/CVE-2022-50259/
`ubuntu`	medium	CVE-2022-50259 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1414 status rows across 9 suites (bionic, focal, jammy, noble, plucky, questing, trusty, upstream, xenial): DNE 1017, ignored 158, released 134, not-affected 104, needs-triage 1.	https://ubuntu.com/security/CVE-2022-50259

Affected software / configurations for CVE-2022-50259

Vendor	Product	Version	Raw CPE
linux	linux_kernel	>= 5.4.14, < 5.4.229	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.5.1, < 5.10.163	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.11, < 5.15.86	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.16, < 6.0.16	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 6.1, < 6.1.2	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	5.5	cpe:2.3:o:linux:linux_kernel:5.5:-::::::
linux	linux_kernel	5.5	cpe:2.3:o:linux:linux_kernel:5.5:rc7::::::

References for CVE-2022-50259

URL	Tags
https://git.kernel.org/stable/c/0a182f8d607464911756b4dbef5d6cad8de22469	Patch
https://git.kernel.org/stable/c/4cabc3af4a6f36c222fecb15858c1060e59218e7	Patch
https://git.kernel.org/stable/c/5c3568166129bc73fd6b37748d2d8f95cd8f22f3	Patch
https://git.kernel.org/stable/c/a443c55d96dede82a724df6e70a318ad15c199e1	Patch
https://git.kernel.org/stable/c/be719496ae6a7fc325e9e5056a52f63ebc84cc0c	Patch
https://git.kernel.org/stable/c/e8b2b392a646bf5cb9413c1cc7a39d99c1b65a62	Patch

URL

CVE-2022-50259 | bpf, sockmap: fix race in sock_map_free()

Exploit prediction scoring system (EPSS) score for CVE-2022-50259

Common vulnerability scoring system (CVSS) metrics for CVE-2022-50259

Weakness enumeration for CVE-2022-50259

OS Trackers for CVE-2022-50259

Affected software / configurations for CVE-2022-50259

References for CVE-2022-50259