{"id":"CVE-2022-50045","title":"powerpc/pci: Fix get_phb_number() locking","summary":"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 f…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= a79e4395619c926ea7e828b2023c0fbe2776385b < 6f75057c21eab12c6ccb7f06f859641a6edfab99","Linux >= 205826dcac3271ab04fb97d66f1b4f8219723259 < 5db5ce0f1963c6c8275719a80cb65e9c98d32726","Linux >= 3ec50b8a0128359ff4ad4061a75c3322d0ab6ac9 < ccb0a42d3f40c436295e0fef57ab613ae5b925a4","Linux >= 47a8fe1b154aa6d836582365b1c70684af8597e4 < a868f771ee41c97a25a04b8c632a7f06689b307b","Linux >= ef0f4eeaba2463a77ac5a4e42c30717deb3c7b62 < 1d9e75c3d8cdf7c96a94cb77450d4ee070279e6a","Linux >= f35c7f506fb96a23a1961c7314c5931ec8bc473e < 90f195c01a2e8d8da6281791617e21109719c981","Linux >= 0fe1e96fef0a5c53b4c0d1500d356f3906000f81 < 8d48562a2729742f767b0fdd994d6b2a56a49c63","Linux e0274da3ac318296fed503422ccda98ce67e99cb","Linux >= 5.18.18 < 5.19","Linux >= 5.10.137 < 5.10.138","Linux >= 5.15.61 < 5.15.63","Linux >= 5.19.2 < 5.19.4"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-05T19:53:24.838996Z"},"published":"2025-06-18","updated":"2026-11-05","sourceUpdated":"2026-11-05T20:00:14.866Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2022-50045","references":[{"url":"https://git.kernel.org/stable/c/6f75057c21eab12c6ccb7f06f859641a6edfab99"},{"url":"https://git.kernel.org/stable/c/5db5ce0f1963c6c8275719a80cb65e9c98d32726"},{"url":"https://git.kernel.org/stable/c/ccb0a42d3f40c436295e0fef57ab613ae5b925a4"},{"url":"https://git.kernel.org/stable/c/a868f771ee41c97a25a04b8c632a7f06689b307b"},{"url":"https://git.kernel.org/stable/c/1d9e75c3d8cdf7c96a94cb77450d4ee070279e6a"},{"url":"https://git.kernel.org/stable/c/90f195c01a2e8d8da6281791617e21109719c981"},{"url":"https://git.kernel.org/stable/c/8d48562a2729742f767b0fdd994d6b2a56a49c63"}],"tags":["cve.org"],"epss":0.00147,"epssPercentile":0.03945,"ingestedAt":"2026-11-05T22:38:31.639Z","slug":"CVE-2022-50045","body":"## Overview\n\nIn 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  [<00000000>] 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't 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's safe, the order of the list is not important.\n\n## Affected\n\n- `Linux >= a79e4395619c926ea7e828b2023c0fbe2776385b < 6f75057c21eab12c6ccb7f06f859641a6edfab99`\n- `Linux >= 205826dcac3271ab04fb97d66f1b4f8219723259 < 5db5ce0f1963c6c8275719a80cb65e9c98d32726`\n- `Linux >= 3ec50b8a0128359ff4ad4061a75c3322d0ab6ac9 < ccb0a42d3f40c436295e0fef57ab613ae5b925a4`\n- `Linux >= 47a8fe1b154aa6d836582365b1c70684af8597e4 < a868f771ee41c97a25a04b8c632a7f06689b307b`\n- `Linux >= ef0f4eeaba2463a77ac5a4e42c30717deb3c7b62 < 1d9e75c3d8cdf7c96a94cb77450d4ee070279e6a`\n- `Linux >= f35c7f506fb96a23a1961c7314c5931ec8bc473e < 90f195c01a2e8d8da6281791617e21109719c981`\n- `Linux >= 0fe1e96fef0a5c53b4c0d1500d356f3906000f81 < 8d48562a2729742f767b0fdd994d6b2a56a49c63`\n- `Linux e0274da3ac318296fed503422ccda98ce67e99cb`\n- `Linux >= 5.18.18 < 5.19`\n- `Linux >= 5.10.137 < 5.10.138`\n- `Linux >= 5.15.61 < 5.15.63`\n- `Linux >= 5.19.2 < 5.19.4`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}