CVE-2021-46999
sctp: do asoc update earlier in sctp_sf_do_dupcook_a
Severity Score
Exploit Likelihood
Affected Versions
Public Exploits
0Exploited in Wild
-Decision
Descriptions
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.
En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: sctp: haga una actualización anterior en sctp_sf_do_dupcook_a Hay un pánico que ocurre en algunos de los entornos, el seguimiento de la llamada es el siguiente: [] falla de protección general, ... 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] Esto se debe a un problema de use-after-free del transporte. Al procesar un fragmento COOKIE-ECHO duplicado en sctp_sf_do_dupcook_a(), tanto los fragmentos COOKIE-ACK como SHUTDOWN se asignan con el transort del nuevo asoc. Sin embargo, más adelante en la máquina de efectos secundarios, el antiguo asoc se utiliza para enviarlos y el Shutdown_last_sent_to del antiguo asoc se configura en el transporte al que se adjuntó el fragmento SHUTDOWN en sctp_cmd_setup_t2(), que en realidad pertenece al nuevo asoc. Después de que se libera el new_asoc y se agota el tiempo de espera T2 del antiguo asoc, se accederá al Shutdown_last_sent_to del antiguo asoc que ya está liberado en sctp_sf_t2_timer_expire(). Gracias Alexander y Jere por ayudarnos a profundizar en este problema. Para solucionarlo, este parche consiste en realizar primero la actualización de asoc y luego asignar los fragmentos COOKIE-ACK y SHUTDOWN con el antiguo asoc 'actualizado'. Esto tendría más sentido, ya que un fragmento de una asoc no debería enviarse con otra asoc. Hemos solucionado bastantes problemas causados por esto.
CVSS Scores
SSVC
- Decision:Track
Timeline
- 2024-02-27 CVE Reserved
- 2024-02-28 CVE Published
- 2024-02-29 EPSS Updated
- 2024-08-04 CVE Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
- ---------- First Exploit
CWE
CAPEC
References (10)
| URL | Tag | Source |
|---|---|---|
| https://git.kernel.org/stable/c/db8bf823e70f239372c62f13e4eb6f08a1665e8c | Vuln. Introduced | |
| https://git.kernel.org/stable/c/a204d577be70e0a0a6023cf1b9859c9ebffaeecd | Vuln. Introduced | |
| https://git.kernel.org/stable/c/145cb2f7177d94bc54563ed26027e952ee0ae03c | Vuln. Introduced | |
| https://git.kernel.org/stable/c/a5ce8531ea508d270822b2bc6140c6198c8a2a7b | Vuln. Introduced |
| URL | Date | SRC |
|---|
| URL | Date | SRC |
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Affected Vendors, Products, and Versions
| Vendor | Product | Version | Other | Status | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Vendor | Product | Version | Other | Status | <-- --> | Vendor | Product | Version | Other | Status |
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 4.19.123 < 4.19.191 Search vendor "Linux" for product "Linux Kernel" and version " >= 4.19.123 < 4.19.191" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 5.4.41 < 5.4.120 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.4.41 < 5.4.120" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 5.7 < 5.10.38 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.7 < 5.10.38" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 5.7 < 5.11.22 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.7 < 5.11.22" | en |
Affected
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| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 5.7 < 5.12.5 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.7 < 5.12.5" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 5.7 < 5.13 Search vendor "Linux" for product "Linux Kernel" and version " >= 5.7 < 5.13" | en |
Affected
| ||||||
| Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | 5.6.13 Search vendor "Linux" for product "Linux Kernel" and version "5.6.13" | en |
Affected
| ||||||