ghsa-752v-r57r-j98p
Vulnerability from github
In the Linux kernel, the following vulnerability has been resolved:
powerpc/pci: Fix get_phb_number() locking
The recent change to get_phb_number() causes a DEBUG_ATOMIC_SLEEP warning on some systems:
BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper preempt_count: 1, expected: 0 RCU nest depth: 0, expected: 0 1 lock held by swapper/1: #0: c157efb0 (hose_spinlock){+.+.}-{2:2}, at: pcibios_alloc_controller+0x64/0x220 Preemption disabled at: [<00000000>] 0x0 CPU: 0 PID: 1 Comm: swapper Not tainted 5.19.0-yocto-standard+ #1 Call Trace: [d101dc90] [c073b264] dump_stack_lvl+0x50/0x8c (unreliable) [d101dcb0] [c0093b70] __might_resched+0x258/0x2a8 [d101dcd0] [c0d3e634] __mutex_lock+0x6c/0x6ec [d101dd50] [c0a84174] of_alias_get_id+0x50/0xf4 [d101dd80] [c002ec78] pcibios_alloc_controller+0x1b8/0x220 [d101ddd0] [c140c9dc] pmac_pci_init+0x198/0x784 [d101de50] [c140852c] discover_phbs+0x30/0x4c [d101de60] [c0007fd4] do_one_initcall+0x94/0x344 [d101ded0] [c1403b40] kernel_init_freeable+0x1a8/0x22c [d101df10] [c00086e0] kernel_init+0x34/0x160 [d101df30] [c001b334] ret_from_kernel_thread+0x5c/0x64
This is because pcibios_alloc_controller() holds hose_spinlock but of_alias_get_id() takes of_mutex which can sleep.
The hose_spinlock protects the phb_bitmap, and also the hose_list, but it doesn't need to be held while get_phb_number() calls the OF routines, because those are only looking up information in the device tree.
So fix it by having get_phb_number() take the hose_spinlock itself, only where required, and then dropping the lock before returning. pcibios_alloc_controller() then needs to take the lock again before the list_add() but that's safe, the order of the list is not important.
{
"affected": [],
"aliases": [
"CVE-2022-50045"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-06-18T11:15:33Z",
"severity": null
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/pci: Fix get_phb_number() locking\n\nThe recent change to get_phb_number() causes a DEBUG_ATOMIC_SLEEP\nwarning on some systems:\n\n BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580\n in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper\n preempt_count: 1, expected: 0\n RCU nest depth: 0, expected: 0\n 1 lock held by swapper/1:\n #0: c157efb0 (hose_spinlock){+.+.}-{2:2}, at: pcibios_alloc_controller+0x64/0x220\n Preemption disabled at:\n [\u003c00000000\u003e] 0x0\n CPU: 0 PID: 1 Comm: swapper Not tainted 5.19.0-yocto-standard+ #1\n Call Trace:\n [d101dc90] [c073b264] dump_stack_lvl+0x50/0x8c (unreliable)\n [d101dcb0] [c0093b70] __might_resched+0x258/0x2a8\n [d101dcd0] [c0d3e634] __mutex_lock+0x6c/0x6ec\n [d101dd50] [c0a84174] of_alias_get_id+0x50/0xf4\n [d101dd80] [c002ec78] pcibios_alloc_controller+0x1b8/0x220\n [d101ddd0] [c140c9dc] pmac_pci_init+0x198/0x784\n [d101de50] [c140852c] discover_phbs+0x30/0x4c\n [d101de60] [c0007fd4] do_one_initcall+0x94/0x344\n [d101ded0] [c1403b40] kernel_init_freeable+0x1a8/0x22c\n [d101df10] [c00086e0] kernel_init+0x34/0x160\n [d101df30] [c001b334] ret_from_kernel_thread+0x5c/0x64\n\nThis is because pcibios_alloc_controller() holds hose_spinlock but\nof_alias_get_id() takes of_mutex which can sleep.\n\nThe hose_spinlock protects the phb_bitmap, and also the hose_list, but\nit doesn\u0027t need to be held while get_phb_number() calls the OF routines,\nbecause those are only looking up information in the device tree.\n\nSo fix it by having get_phb_number() take the hose_spinlock itself, only\nwhere required, and then dropping the lock before returning.\npcibios_alloc_controller() then needs to take the lock again before the\nlist_add() but that\u0027s safe, the order of the list is not important.",
"id": "GHSA-752v-r57r-j98p",
"modified": "2025-06-18T12:30:44Z",
"published": "2025-06-18T12:30:44Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-50045"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1d9e75c3d8cdf7c96a94cb77450d4ee070279e6a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/5db5ce0f1963c6c8275719a80cb65e9c98d32726"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/6f75057c21eab12c6ccb7f06f859641a6edfab99"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8d48562a2729742f767b0fdd994d6b2a56a49c63"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/90f195c01a2e8d8da6281791617e21109719c981"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/a868f771ee41c97a25a04b8c632a7f06689b307b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ccb0a42d3f40c436295e0fef57ab613ae5b925a4"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
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