CVE-2022-50405

net/tunnel: wait until all sk_user_data reader finish before releasing the sock

State: Published
Severity: 7.8 High
Published: Sep 18, 2025
Updated: Aug 5, 2026
Reserved: Sep 17, 2025

Description

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

net/tunnel: wait until all sk_user_data reader finish before releasing the sock

There is a race condition in vxlan that when deleting a vxlan device during receiving packets, there is a possibility that the sock is released after getting vxlan_sock vs from sk_user_data. Then in later vxlan_ecn_decapsulate(), vxlan_get_sk_family() we will got NULL pointer dereference. e.g.

#0 [ffffa25ec6978a38] machine_kexec at ffffffff8c669757 #1 [ffffa25ec6978a90] __crash_kexec at ffffffff8c7c0a4d #2 [ffffa25ec6978b58] crash_kexec at ffffffff8c7c1c48 #3 [ffffa25ec6978b60] oops_end at ffffffff8c627f2b #4 [ffffa25ec6978b80] page_fault_oops at ffffffff8c678fcb #5 [ffffa25ec6978bd8] exc_page_fault at ffffffff8d109542 #6 [ffffa25ec6978c00] asm_exc_page_fault at ffffffff8d200b62 [exception RIP: vxlan_ecn_decapsulate+0x3b] RIP: ffffffffc1014e7b RSP: ffffa25ec6978cb0 RFLAGS: 00010246 RAX: 0000000000000008 RBX: ffff8aa000888000 RCX: 0000000000000000 RDX: 000000000000000e RSI: ffff8a9fc7ab803e RDI: ffff8a9fd1168700 RBP: ffff8a9fc7ab803e R8: 0000000000700000 R9: 00000000000010ae R10: ffff8a9fcb748980 R11: 0000000000000000 R12: ffff8a9fd1168700 R13: ffff8aa000888000 R14: 00000000002a0000 R15: 00000000000010ae ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #7 [ffffa25ec6978ce8] vxlan_rcv at ffffffffc10189cd [vxlan] #8 [ffffa25ec6978d90] udp_queue_rcv_one_skb at ffffffff8cfb6507 #9 [ffffa25ec6978dc0] udp_unicast_rcv_skb at ffffffff8cfb6e45 #10 [ffffa25ec6978dc8] __udp4_lib_rcv at ffffffff8cfb8807 #11 [ffffa25ec6978e20] ip_protocol_deliver_rcu at ffffffff8cf76951 #12 [ffffa25ec6978e48] ip_local_deliver at ffffffff8cf76bde #13 [ffffa25ec6978ea0] __netif_receive_skb_one_core at ffffffff8cecde9b #14 [ffffa25ec6978ec8] process_backlog at ffffffff8cece139 #15 [ffffa25ec6978f00] __napi_poll at ffffffff8ceced1a #16 [ffffa25ec6978f28] net_rx_action at ffffffff8cecf1f3 #17 [ffffa25ec6978fa0] __softirqentry_text_start at ffffffff8d4000ca #18 [ffffa25ec6978ff0] do_softirq at ffffffff8c6fbdc3

Reproducer: https://github.com/Mellanox/ovs-tests/blob/master/test-ovs-vxlan-remove-tunnel-during-traffic.sh

Fix this by waiting for all sk_user_data reader to finish before releasing the sock.

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	Linux
3.1	5.5 Medium	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H	CISA-ADP

Weaknesses

CWE-476 NULL Pointer Dereference

Affected Products

Product	Versions
LinuxLinux	6a93cc9052748c6355ec9d5b6c38b77f85f1cb0d to before e8316584b0a6c61c9c407631040c22712b26e38cAffected 6a93cc9052748c6355ec9d5b6c38b77f85f1cb0d to before 84e566d157cc22ad2da8bdd970495855fbf13d92Affected 6a93cc9052748c6355ec9d5b6c38b77f85f1cb0d to before be34e79e0ae6adbf6e7e75ddaee9ad84795ab933Affected 6a93cc9052748c6355ec9d5b6c38b77f85f1cb0d to before 303000c793f705d07b551eb7c1c27001c5b33c8dAffected 6a93cc9052748c6355ec9d5b6c38b77f85f1cb0d to before 91f09a776ae335ca836ed864b8f2a9461882a280Affected 6a93cc9052748c6355ec9d5b6c38b77f85f1cb0d to before 9a6544343bba7da929d6d4a2dc44ec0f15970081Affected 6a93cc9052748c6355ec9d5b6c38b77f85f1cb0d to before b38aa7465411795e9e744b8d94633910497fec2aAffected 6a93cc9052748c6355ec9d5b6c38b77f85f1cb0d to before 588d0b8462f5ffed3e677e65639825b2678117abAffected 6a93cc9052748c6355ec9d5b6c38b77f85f1cb0d to before 3cf7203ca620682165706f70a1b12b5194607dceAffected
LinuxLinux	3.18Affected before 3.18Not affected 4.9.337 through 4.9.Not affected 4.14.303 through 4.14.Not affected 4.19.270 through 4.19.Not affected 5.4.229 through 5.4.Not affected 5.10.163 through 5.10.Not affected 5.15.86 through 5.15.Not affected 6.0.16 through 6.0.Not affected 6.1.2 through 6.1.Not affected 6.2 and laterNot affected

Product

Versions

LinuxLinux

6a93cc9052748c6355ec9d5b6c38b77f85f1cb0d to before e8316584b0a6c61c9c407631040c22712b26e38cAffected
6a93cc9052748c6355ec9d5b6c38b77f85f1cb0d to before 84e566d157cc22ad2da8bdd970495855fbf13d92Affected
6a93cc9052748c6355ec9d5b6c38b77f85f1cb0d to before be34e79e0ae6adbf6e7e75ddaee9ad84795ab933Affected
6a93cc9052748c6355ec9d5b6c38b77f85f1cb0d to before 303000c793f705d07b551eb7c1c27001c5b33c8dAffected
6a93cc9052748c6355ec9d5b6c38b77f85f1cb0d to before 91f09a776ae335ca836ed864b8f2a9461882a280Affected
6a93cc9052748c6355ec9d5b6c38b77f85f1cb0d to before 9a6544343bba7da929d6d4a2dc44ec0f15970081Affected
6a93cc9052748c6355ec9d5b6c38b77f85f1cb0d to before b38aa7465411795e9e744b8d94633910497fec2aAffected
6a93cc9052748c6355ec9d5b6c38b77f85f1cb0d to before 588d0b8462f5ffed3e677e65639825b2678117abAffected
6a93cc9052748c6355ec9d5b6c38b77f85f1cb0d to before 3cf7203ca620682165706f70a1b12b5194607dceAffected

LinuxLinux

3.18Affected
before 3.18Not affected
4.9.337 through 4.9.*Not affected
4.14.303 through 4.14.*Not affected
4.19.270 through 4.19.*Not affected
5.4.229 through 5.4.*Not affected
5.10.163 through 5.10.*Not affected
5.15.86 through 5.15.*Not affected
6.0.16 through 6.0.*Not affected
6.1.2 through 6.1.*Not affected
6.2 and laterNot affected

References

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