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Vulnerability · Published Feb 28, 2024 · Assigned by Linux

CVE-2021-46999sctp: do asoc update earlier in sctp_sf_do_dupcook_a

Critical 9.8

In plain English

A critical-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 55% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)9.8Critical
Exploit odds (30 days)0.7%top 45.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: sctp: do asoc update earlier in sctp_sf_do_dupcook_a There's a panic that occurs in a few of envs, the call trace is as below: [] general protection fault, ... 0x29acd70f1000a: 0000 [#1] SMP PTI [] RIP: 0010:sctp_ulpevent_notify_peer_addr_change+0x4b/0x1fa [sctp] [] sctp_assoc_control_transport+0x1b9/0x210 [sctp] [] sctp_do_8_2_transport_strike.isra.16+0x15c/0x220 [sctp] [] sctp_cmd_interpreter.isra.21+0x1231/0x1a10 [sctp] [] sctp_do_sm+0xc3/0x2a0 [sctp] [] sctp_generate_timeout_event+0x81/0xf0 [sctp] This is caused by a transport use-after-free issue. When processing a duplicate COOKIE-ECHO chunk in sctp_sf_do_dupcook_a(), both COOKIE-ACK and SHUTDOWN chunks are allocated with the transort from the new asoc. However, later in the sideeffect machine, the old asoc is used to send them out and old asoc's shutdown_last_sent_to is set to the transport that SHUTDOWN chunk attached to in sctp_cmd_setup_t2(), which actually belongs to the new asoc. After the new_asoc is freed and the old asoc T2 timeout, the old asoc's shutdown_last_sent_to that is already freed would be accessed in sctp_sf_t2_timer_expire(). Thanks Alexander and Jere for helping dig into this issue. To fix it, this patch is to do the asoc update first, then allocate the COOKIE-ACK and SHUTDOWN chunks with the 'updated' old asoc. This would make more sense, as a chunk from an asoc shouldn't be sent out with another asoc. We had fixed quite a few issues caused by this.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux5.10.38-1DEBIAN-CVE-2021-46999
Debian:13linux5.10.38-1DEBIAN-CVE-2021-46999
Debian:14linux5.10.38-1DEBIAN-CVE-2021-46999
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2021-46999
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2021-46999
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2021-46999
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2021-46999
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2021-46999
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2021-46999
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2021-46999
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2021-46999
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2021-46999
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2021-46999
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2021-46999
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2021-46999
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2021-46999
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2021-46999
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2021-46999
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2021-46999
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2021-46999
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2021-46999
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2021-46999
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2021-46999
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2021-46999
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2021-46999
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2021-46999
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2021-46999

Affected products (as reported)

VendorProductVersions
Linux Linux db8bf823e70f239372c62f13e4eb6f08a1665e8c – before d624f2991b977821375fbd56c91b0c91d456a697a204d577be70e0a0a6023cf1b9859c9ebffaeecd – before b1b31948c0af44628e43353828453461bb74098f145cb2f7177d94bc54563ed26027e952ee0ae03c – before f01988ecf3654f805282dce2d3bb9afe68d2691e145cb2f7177d94bc54563ed26027e952ee0ae03c – before 61b877bad9bb0d82b7d8841be50872557090a704145cb2f7177d94bc54563ed26027e952ee0ae03c – before 0bfd913c2121b3d553bfd52810fe6061d542d625145cb2f7177d94bc54563ed26027e952ee0ae03c – before 35b4f24415c854cd718ccdf38dbea6297f010aaea5ce8531ea508d270822b2bc6140c6198c8a2a7b4.19.123 – before 4.19.191
Linux Linux 5.7

References