{"id":"AZL-48813","summary":"CVE-2024-36972 affecting package kernel for versions less than 5.15.176.3-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\naf_unix: Update unix_sk(sk)-\u003eoob_skb under sk_receive_queue lock.\n\nBilly Jheng Bing-Jhong reported a race between __unix_gc() and\nqueue_oob().\n\n__unix_gc() tries to garbage-collect close()d inflight sockets,\nand then if the socket has MSG_OOB in unix_sk(sk)-\u003eoob_skb, GC\nwill drop the reference and set NULL to it locklessly.\n\nHowever, the peer socket still can send MSG_OOB message and\nqueue_oob() can update unix_sk(sk)-\u003eoob_skb concurrently, leading\nNULL pointer dereference. [0]\n\nTo fix the issue, let's update unix_sk(sk)-\u003eoob_skb under the\nsk_receive_queue's lock and take it everywhere we touch oob_skb.\n\nNote that we defer kfree_skb() in manage_oob() to silence lockdep\nfalse-positive (See [1]).\n\n[0]:\nBUG: kernel NULL pointer dereference, address: 0000000000000008\n PF: supervisor write access in kernel mode\n PF: error_code(0x0002) - not-present page\nPGD 8000000009f5e067 P4D 8000000009f5e067 PUD 9f5d067 PMD 0\nOops: 0002 [#1] PREEMPT SMP PTI\nCPU: 3 PID: 50 Comm: kworker/3:1 Not tainted 6.9.0-rc5-00191-gd091e579b864 #110\nHardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.0-0-gd239552ce722-prebuilt.qemu.org 04/01/2014\nWorkqueue: events delayed_fput\nRIP: 0010:skb_dequeue (./include/linux/skbuff.h:2386 ./include/linux/skbuff.h:2402 net/core/skbuff.c:3847)\nCode: 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 \u003c48\u003e 89 42 08 48 89 10 e8 e7 c5 42 00 4c 89 e0 5b 5d 41 5c c3 cc cc\nRSP: 0018:ffffc900001bfd48 EFLAGS: 00000002\nRAX: 0000000000000000 RBX: ffff8880088f5ae8 RCX: 00000000361289f9\nRDX: 0000000000000000 RSI: 0000000000000206 RDI: ffff8880088f5b00\nRBP: ffff8880088f5b00 R08: 0000000000080000 R09: 0000000000000001\nR10: 0000000000000003 R11: 0000000000000001 R12: ffff8880056b6a00\nR13: ffff8880088f5280 R14: 0000000000000001 R15: ffff8880088f5a80\nFS:  0000000000000000(0000) GS:ffff88807dd80000(0000) knlGS:0000000000000000\nCS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 0000000000000008 CR3: 0000000006314000 CR4: 00000000007506f0\nPKRU: 55555554\nCall Trace:\n \u003cTASK\u003e\n unix_release_sock (net/unix/af_unix.c:654)\n unix_release (net/unix/af_unix.c:1050)\n __sock_release (net/socket.c:660)\n sock_close (net/socket.c:1423)\n __fput (fs/file_table.c:423)\n delayed_fput (fs/file_table.c:444 (discriminator 3))\n process_one_work (kernel/workqueue.c:3259)\n worker_thread (kernel/workqueue.c:3329 kernel/workqueue.c:3416)\n kthread (kernel/kthread.c:388)\n ret_from_fork (arch/x86/kernel/process.c:153)\n ret_from_fork_asm (arch/x86/entry/entry_64.S:257)\n \u003c/TASK\u003e\nModules linked in:\nCR2: 0000000000000008","modified":"2026-04-01T05:17:16.431397Z","published":"2024-06-10T15:15:52Z","upstream":["CVE-2024-36972"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-36972"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:2","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"5.15.176.3-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-48813.json"}}],"schema_version":"1.7.5"}