CVE-2024-36972

En el kernel de Linux, se ha resuelto la siguiente vulnerabilidad: af_unix: actualice unix_sk(sk)->oob_skb bajo el bloqueo sk_receive_queue. Billy Jheng Bing-Jhong informó de una ejecución entre __unix_gc() y queue_oob(). __unix_gc() intenta recolectar basura de sockets en vuelo close()d, y luego, si el socket tiene MSG_OOB en unix_sk(sk)->oob_skb, GC eliminará la referencia y establecerá NULL sin bloqueo. Sin embargo, el socket del par aún puede enviar el mensaje MSG_OOB y queue_oob() puede actualizar unix_sk(sk)->oob_skb simultáneamente, lo que lleva a la desreferencia del puntero NULL. [0] Para solucionar el problema, actualicemos unix_sk(sk)->oob_skb bajo el bloqueo de sk_receive_queue y lo llevemos a todos los lugares donde toquemos oob_skb. Tenga en cuenta que posponemos kfree_skb() en Manage_oob() para silenciar el falso positivo de Lockdep (consulte [1]). [0]: ERROR: desreferencia del puntero NULL del kernel, dirección: 0000000000000008 PF: acceso de escritura del supervisor en modo kernel PF: error_code(0x0002) - página no presente PGD 8000000009f5e067 P4D 8000000009f5e067 PUD 9f5d067 PMD 0 Ups: 02 [#1] SMP ADELANTADO PTI CPU: 3 PID: 50 Comm: kworker/3:1 No contaminado 6.9.0-rc5-00191-gd091e579b864 #110 Nombre del hardware: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0- gd239552ce722-prebuilt.qemu.org 01/04/2014 Cola de trabajo: eventos retrasados_fput RIP: 0010:skb_dequeue (./include/linux/skbuff.h:2386 ./include/linux/skbuff.h:2402 net/core/skbuff. c:3847) Código: 39 e3 74 3e 8b 43 10 48 89 ef 83 e8 01 89 43 10 49 8b 44 24 08 49 c7 44 24 08 00 00 00 00 49 8b 14 24 49 c7 04 24 00 0 00 00 <48 > 89 42 08 48 89 10 e8 e7 c5 42 00 4c 89 e0 5b 5d 41 5c c3 cc cc RSP: 0018:ffffc900001bfd48 EFLAGS: 00000002 RAX: 0000000000000000 RBX: 80088f5ae8 RCX: 00000000361289f9 RDX: 0000000000000000 RSI: 0000000000000206 RDI: ffff8880088f5b00 RBP: ffff8880088f5b00 R08: 0000000000080000 R09: 0000000000000001 R10: 0000000000000003 R11: 00000000000000001 R12: ffff8880056b6a00 R13: ffff8880088f5280 R14: 0000000000000001 R15: ffff8880088f5a80 FS: 0000000000000000(0000) GS:ffff88807dd80000(0000) knlGS:00000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0 : 0000000080050033 CR2: 0000000000000008 CR3: 0000000006314000 CR4: 00000000007506f0 PKRU: 55555554 Seguimiento de llamadas: unix_release_sock (net/unix/af_unix.c:654) ix_release (net/unix/af_unix.c:1050) __sock_release (net/socket. c:660) sock_close (net/socket.c:1423) __fput (fs/file_table.c:423) retrasado_fput (fs/file_table.c:444 (discriminador 3)) Process_one_work (kernel/workqueue.c:3259) trabajador_thread ( kernel/workqueue.c:3329 kernel/workqueue.c:3416) kthread (kernel/kthread.c:388) ret_from_fork (arch/x86/kernel/process.c:153) ret_from_fork_asm (arch/x86/entry/entry_64.S :257) Módulos vinculados en: CR2: 0000000000000008

In the Linux kernel, the following vulnerability has been resolved: af_unix: Update unix_sk(sk)->oob_skb under sk_receive_queue lock. Billy Jheng Bing-Jhong reported a race between __unix_gc() and queue_oob(). __unix_gc() tries to garbage-collect close()d inflight sockets, and then if the socket has MSG_OOB in unix_sk(sk)->oob_skb, GC will drop the reference and set NULL to it locklessly. However, the peer socket still can send MSG_OOB message and queue_oob() can update unix_sk(sk)->oob_skb concurrently, leading NULL pointer dereference. [0] To fix the issue, let's update unix_sk(sk)->oob_skb under the sk_receive_queue's lock and take it everywhere we touch oob_skb. Note that we defer kfree_skb() in manage_oob() to silence lockdep false-positive (See [1]). [0]: BUG: kernel NULL pointer dereference, address: 0000000000000008 PF: supervisor write access in kernel mode PF: error_code(0x0002) - not-present page PGD 8000000009f5e067 P4D 8000000009f5e067 PUD 9f5d067 PMD 0 Oops: 0002 [#1] PREEMPT SMP PTI CPU: 3 PID: 50 Comm: kworker/3:1 Not tainted 6.9.0-rc5-00191-gd091e579b864 #110 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014 Workqueue: events delayed_fput RIP: 0010:skb_dequeue (./include/linux/skbuff.h:2386 ./include/linux/skbuff.h:2402 net/core/skbuff.c:3847) Code: 39 e3 74 3e 8b 43 10 48 89 ef 83 e8 01 89 43 10 49 8b 44 24 08 49 c7 44 24 08 00 00 00 00 49 8b 14 24 49 c7 04 24 00 00 00 00 <48> 89 42 08 48 89 10 e8 e7 c5 42 00 4c 89 e0 5b 5d 41 5c c3 cc cc RSP: 0018:ffffc900001bfd48 EFLAGS: 00000002 RAX: 0000000000000000 RBX: ffff8880088f5ae8 RCX: 00000000361289f9 RDX: 0000000000000000 RSI: 0000000000000206 RDI: ffff8880088f5b00 RBP: ffff8880088f5b00 R08: 0000000000080000 R09: 0000000000000001 R10: 0000000000000003 R11: 0000000000000001 R12: ffff8880056b6a00 R13: ffff8880088f5280 R14: 0000000000000001 R15: ffff8880088f5a80 FS: 0000000000000000(0000) GS:ffff88807dd80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000008 CR3: 0000000006314000 CR4: 00000000007506f0 PKRU: 55555554 Call Trace: <TASK> unix_release_sock (net/unix/af_unix.c:654) unix_release (net/unix/af_unix.c:1050) __sock_release (net/socket.c:660) sock_close (net/socket.c:1423) __fput (fs/file_table.c:423) delayed_fput (fs/file_table.c:444 (discriminator 3)) process_one_work (kernel/workqueue.c:3259) worker_thread (kernel/workqueue.c:3329 kernel/workqueue.c:3416) kthread (kernel/kthread.c:388) ret_from_fork (arch/x86/kernel/process.c:153) ret_from_fork_asm (arch/x86/entry/entry_64.S:257) </TASK> Modules linked in: CR2: 0000000000000008

Ziming Zhang discovered that the DRM driver for VMware Virtual GPU did not properly handle certain error conditions, leading to a NULL pointer dereference. A local attacker could possibly trigger this vulnerability to cause a denial of service. Gui-Dong Han discovered that the software RAID driver in the Linux kernel contained a race condition, leading to an integer overflow vulnerability. A privileged attacker could possibly use this to cause a denial of service.