ghsa-j2g4-vr97-pwvm
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
af_unix: Drop oob_skb ref before purging queue in GC.
syzbot reported another task hung in __unix_gc(). [0]
The current while loop assumes that all of the left candidates have oob_skb and calling kfree_skb(oob_skb) releases the remaining candidates.
However, I missed a case that oob_skb has self-referencing fd and another fd and the latter sk is placed before the former in the candidate list. Then, the while loop never proceeds, resulting the task hung.
__unix_gc() has the same loop just before purging the collected skb, so we can call kfree_skb(oob_skb) there and let __skb_queue_purge() release all inflight sockets.
[0]:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 2784 Comm: kworker/u4:8 Not tainted 6.8.0-rc4-syzkaller-01028-g71b605d32017 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024
Workqueue: events_unbound __unix_gc
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:200
Code: 89 fb e8 23 00 00 00 48 8b 3d 84 f5 1a 0c 48 89 de 5b e9 43 26 57 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
{
"affected": [],
"aliases": [
"CVE-2024-26750"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2024-04-04T09:15:07Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\naf_unix: Drop oob_skb ref before purging queue in GC.\n\nsyzbot reported another task hung in __unix_gc(). [0]\n\nThe current while loop assumes that all of the left candidates\nhave oob_skb and calling kfree_skb(oob_skb) releases the remaining\ncandidates.\n\nHowever, I missed a case that oob_skb has self-referencing fd and\nanother fd and the latter sk is placed before the former in the\ncandidate list. Then, the while loop never proceeds, resulting\nthe task hung.\n\n__unix_gc() has the same loop just before purging the collected skb,\nso we can call kfree_skb(oob_skb) there and let __skb_queue_purge()\nrelease all inflight sockets.\n\n[0]:\nSending NMI from CPU 0 to CPUs 1:\nNMI backtrace for cpu 1\nCPU: 1 PID: 2784 Comm: kworker/u4:8 Not tainted 6.8.0-rc4-syzkaller-01028-g71b605d32017 #0\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/25/2024\nWorkqueue: events_unbound __unix_gc\nRIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:200\nCode: 89 fb e8 23 00 00 00 48 8b 3d 84 f5 1a 0c 48 89 de 5b e9 43 26 57 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 \u003cf3\u003e 0f 1e fa 48 8b 04 24 65 48 8b 0d 90 52 70 7e 65 8b 15 91 52 70\nRSP: 0018:ffffc9000a17fa78 EFLAGS: 00000287\nRAX: ffffffff8a0a6108 RBX: ffff88802b6c2640 RCX: ffff88802c0b3b80\nRDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000000000\nRBP: ffffc9000a17fbf0 R08: ffffffff89383f1d R09: 1ffff1100ee5ff84\nR10: dffffc0000000000 R11: ffffed100ee5ff85 R12: 1ffff110056d84ee\nR13: ffffc9000a17fae0 R14: 0000000000000000 R15: ffffffff8f47b840\nFS: 0000000000000000(0000) GS:ffff8880b9500000(0000) knlGS:0000000000000000\nCS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\nCR2: 00007ffef5687ff8 CR3: 0000000029b34000 CR4: 00000000003506f0\nDR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000\nDR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400\nCall Trace:\n \u003cNMI\u003e\n \u003c/NMI\u003e\n \u003cTASK\u003e\n __unix_gc+0xe69/0xf40 net/unix/garbage.c:343\n process_one_work kernel/workqueue.c:2633 [inline]\n process_scheduled_works+0x913/0x1420 kernel/workqueue.c:2706\n worker_thread+0xa5f/0x1000 kernel/workqueue.c:2787\n kthread+0x2ef/0x390 kernel/kthread.c:388\n ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147\n ret_from_fork_asm+0x1b/0x30 arch/x86/entry/entry_64.S:242\n \u003c/TASK\u003e",
"id": "GHSA-j2g4-vr97-pwvm",
"modified": "2024-04-04T15:30:33Z",
"published": "2024-04-04T09:30:35Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-26750"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/43ba9e331559a30000c862eea313248707afa787"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6c480d0f131862645d172ca9e25dc152b1a5c3a6"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/aa82ac51d63328714645c827775d64dbfd9941f3"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/c4c795b21dd23d9514ae1c6646c3fb2c78b5be60"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/e9eac260369d0cf57ea53df95427125725507a0d"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
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