CVE-2024-26725
dpll: fix possible deadlock during netlink dump operation
Severity Score
Exploit Likelihood
Affected Versions
Public Exploits
0Exploited in Wild
-Decision
Descriptions
In the Linux kernel, the following vulnerability has been resolved:
dpll: fix possible deadlock during netlink dump operation
Recently, I've been hitting following deadlock warning during dpll pin
dump:
[52804.637962] ======================================================
[52804.638536] WARNING: possible circular locking dependency detected
[52804.639111] 6.8.0-rc2jiri+ #1 Not tainted
[52804.639529] ------------------------------------------------------
[52804.640104] python3/2984 is trying to acquire lock:
[52804.640581] ffff88810e642678 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}, at: netlink_dump+0xb3/0x780
[52804.641417]
but task is already holding lock:
[52804.642010] ffffffff83bde4c8 (dpll_lock){+.+.}-{3:3}, at: dpll_lock_dumpit+0x13/0x20
[52804.642747]
which lock already depends on the new lock.
[52804.643551]
the existing dependency chain (in reverse order) is:
[52804.644259]
-> #1 (dpll_lock){+.+.}-{3:3}:
[52804.644836] lock_acquire+0x174/0x3e0
[52804.645271] __mutex_lock+0x119/0x1150
[52804.645723] dpll_lock_dumpit+0x13/0x20
[52804.646169] genl_start+0x266/0x320
[52804.646578] __netlink_dump_start+0x321/0x450
[52804.647056] genl_family_rcv_msg_dumpit+0x155/0x1e0
[52804.647575] genl_rcv_msg+0x1ed/0x3b0
[52804.648001] netlink_rcv_skb+0xdc/0x210
[52804.648440] genl_rcv+0x24/0x40
[52804.648831] netlink_unicast+0x2f1/0x490
[52804.649290] netlink_sendmsg+0x36d/0x660
[52804.649742] __sock_sendmsg+0x73/0xc0
[52804.650165] __sys_sendto+0x184/0x210
[52804.650597] __x64_sys_sendto+0x72/0x80
[52804.651045] do_syscall_64+0x6f/0x140
[52804.651474] entry_SYSCALL_64_after_hwframe+0x46/0x4e
[52804.652001]
-> #0 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}:
[52804.652650] check_prev_add+0x1ae/0x1280
[52804.653107] __lock_acquire+0x1ed3/0x29a0
[52804.653559] lock_acquire+0x174/0x3e0
[52804.653984] __mutex_lock+0x119/0x1150
[52804.654423] netlink_dump+0xb3/0x780
[52804.654845] __netlink_dump_start+0x389/0x450
[52804.655321] genl_family_rcv_msg_dumpit+0x155/0x1e0
[52804.655842] genl_rcv_msg+0x1ed/0x3b0
[52804.656272] netlink_rcv_skb+0xdc/0x210
[52804.656721] genl_rcv+0x24/0x40
[52804.657119] netlink_unicast+0x2f1/0x490
[52804.657570] netlink_sendmsg+0x36d/0x660
[52804.658022] __sock_sendmsg+0x73/0xc0
[52804.658450] __sys_sendto+0x184/0x210
[52804.658877] __x64_sys_sendto+0x72/0x80
[52804.659322] do_syscall_64+0x6f/0x140
[52804.659752] entry_SYSCALL_64_after_hwframe+0x46/0x4e
[52804.660281]
other info that might help us debug this:
[52804.661077] Possible unsafe locking scenario:
[52804.661671] CPU0 CPU1
[52804.662129] ---- ----
[52804.662577] lock(dpll_lock);
[52804.662924] lock(nlk_cb_mutex-GENERIC);
[52804.663538] lock(dpll_lock);
[52804.664073] lock(nlk_cb_mutex-GENERIC);
[52804.664490]
The issue as follows: __netlink_dump_start() calls control->start(cb)
with nlk->cb_mutex held. In control->start(cb) the dpll_lock is taken.
Then nlk->cb_mutex is released and taken again in netlink_dump(), while
dpll_lock still being held. That leads to ABBA deadlock when another
CPU races with the same operation.
Fix this by moving dpll_lock taking into dumpit() callback which ensures
correct lock taking order.
En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: dpll: soluciona un posible punto muerto durante la operación de volcado de netlink Recientemente, he estado recibiendo la siguiente advertencia de punto muerto durante el volcado de pin de dpll: [52804.637962] =========== =========================================== [52804.638536] ADVERTENCIA: posible circular dependencia de bloqueo detectada [52804.639111] 6.8.0-rc2jiri+ #1 No contaminado [52804.639529] -------------------------------- ---------------------- [52804.640104] python3/2984 está intentando adquirir el bloqueo: [52804.640581] ffff88810e642678 (nlk_cb_mutex-GENERIC){+.+.}- {3:3}, en: netlink_dump+0xb3/0x780 [52804.641417] pero la tarea ya mantiene el bloqueo: [52804.642010] ffffffff83bde4c8 (dpll_lock){+.+.}-{3:3}, en: dpll_lock_dumpit+0x13/0x20 [52804.642747] qué bloqueo ya depende del nuevo bloqueo. [52804.643551] la cadena de dependencia existente (en orden inverso) es: [52804.644259] -> #1 (dpll_lock){+.+.}-{3:3}: [52804.644836] lock_acquire+0x174/0x3e0 [52804.645271] __mutex_lock+ 0x119/0x1150 [52804.645723] dpll_lock_dumpit+0x13/0x20 [52804.646169] genl_start+0x266/0x320 [52804.646578] __netlink_dump_start+0x321/0x450 [52804.647056 ] genl_family_rcv_msg_dumpit+0x155/0x1e0 [52804.647575] genl_rcv_msg+0x1ed/0x3b0 [52804.648001] netlink_rcv_skb+0xdc/ 0x210 [52804.648440] genl_rcv+0x24/0x40 [52804.648831] netlink_unicast+0x2f1/0x490 [52804.649290] netlink_sendmsg+0x36d/0x660 [52804.649742] __sock_sendmsg +0x73/0xc0 [52804.650165] __sys_sendto+0x184/0x210 [52804.650597] __x64_sys_sendto+0x72/0x80 [ 52804.651045] do_syscall_64+0x6f/0x140 [52804.651474] Entry_SYSCALL_64_after_hwframe+0x46/0x4e [52804.652001] -> #0 (nlk_cb_mutex-GENERIC){+.+.}-{3:3}: [52804.6 52650] check_prev_add+0x1ae/0x1280 [52804.653107 ] __lock_acquire+0x1ed3/0x29a0 [52804.653559] lock_acquire+0x174/0x3e0 [52804.653984] __mutex_lock+0x119/0x1150 [52804.654423] netlink_dump+0xb3/0x780 [52804.654 845] __netlink_dump_start+0x389/0x450 [52804.655321] genl_family_rcv_msg_dumpit+0x155/0x1e0 [52804.655842] genl_rcv_msg +0x1ed/0x3b0 [52804.656272] netlink_rcv_skb+0xdc/0x210 [52804.656721] genl_rcv+0x24/0x40 [52804.657119] netlink_unicast+0x2f1/0x490 [52804.657570] netlink_sendm sg+0x36d/0x660 [52804.658022] __sock_sendmsg+0x73/0xc0 [52804.658450] __sys_sendto+0x184 /0x210 [52804.658877] __x64_sys_sendto+0x72/0x80 [52804.659322] do_syscall_64+0x6f/0x140 [52804.659752] Entry_SYSCALL_64_after_hwframe+0x46/0x4e [52804.66 0281] otra información que podría ayudarnos a depurar esto: [52804.661077] Posible escenario de bloqueo inseguro: [52804.661671] CPU0 CPU1 [52804.662129] ---- ---- [52804.662577] bloqueo(dpll_lock); [52804.662924] bloqueo (nlk_cb_mutex-GENERIC); [52804.663538] bloqueo(dpll_lock); [52804.664073] bloqueo (nlk_cb_mutex-GENERIC); [52804.664490] El problema es el siguiente: __netlink_dump_start() llama a control->start(cb) con nlk->cb_mutex retenido. En control->start(cb) se toma dpll_lock. Luego, nlk->cb_mutex se libera y se toma nuevamente en netlink_dump(), mientras dpll_lock aún se mantiene. Eso lleva a un punto muerto de ABBA cuando otra CPU corre con la misma operación. Solucione este problema moviendo dpll_lock a la devolución de llamada dumpit(), lo que garantiza el orden correcto de toma de bloqueo.
CVSS Scores
SSVC
- Decision:Track
Timeline
- 2024-02-19 CVE Reserved
- 2024-04-03 CVE Published
- 2024-04-04 EPSS Updated
- 2024-09-11 CVE Updated
- ---------- Exploited in Wild
- ---------- KEV Due Date
- ---------- First Exploit
CWE
CAPEC
References (3)
URL | Tag | Source |
---|---|---|
https://git.kernel.org/stable/c/9d71b54b65b1fb6c0d3a6c5c88ba9b915c783fbc | Vuln. Introduced |
URL | Date | SRC |
---|
URL | Date | SRC |
---|---|---|
https://git.kernel.org/stable/c/087739cbd0d0b87b6cec2c0799436ac66e24acc8 | 2024-02-23 | |
https://git.kernel.org/stable/c/53c0441dd2c44ee93fddb5473885fd41e4bc2361 | 2024-02-09 |
URL | Date | SRC |
---|
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" | >= 6.7 < 6.7.6 Search vendor "Linux" for product "Linux Kernel" and version " >= 6.7 < 6.7.6" | en |
Affected
| ||||||
Linux Search vendor "Linux" | Linux Kernel Search vendor "Linux" for product "Linux Kernel" | >= 6.7 < 6.8 Search vendor "Linux" for product "Linux Kernel" and version " >= 6.7 < 6.8" | en |
Affected
|