CVE-2022-50045
powerpc/pci: Fix get_phb_number() locking
- Published
- Updated
- Reserved
- Assigned by
- Linux
Description
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.
Timeline
ID reserved
By Linux
Published
- 17 months later
· 17 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Analyzed | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.15% · top 96% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Weakness
Affected products
- affected a79e4395619c926ea7e828b2023c0fbe2776385b – < 6f75057c21eab12c6ccb7f06f859641a6edfab99
- affected 205826dcac3271ab04fb97d66f1b4f8219723259 – < 5db5ce0f1963c6c8275719a80cb65e9c98d32726
- affected 3ec50b8a0128359ff4ad4061a75c3322d0ab6ac9 – < ccb0a42d3f40c436295e0fef57ab613ae5b925a4
- affected 47a8fe1b154aa6d836582365b1c70684af8597e4 – < a868f771ee41c97a25a04b8c632a7f06689b307b
- affected ef0f4eeaba2463a77ac5a4e42c30717deb3c7b62 – < 1d9e75c3d8cdf7c96a94cb77450d4ee070279e6a
- affected f35c7f506fb96a23a1961c7314c5931ec8bc473e – < 90f195c01a2e8d8da6281791617e21109719c981
- affected 0fe1e96fef0a5c53b4c0d1500d356f3906000f81 – < 8d48562a2729742f767b0fdd994d6b2a56a49c63
- affected e0274da3ac318296fed503422ccda98ce67e99cb
- affected 5.18.18 – < 5.19
- affected 5.10.137 – < 5.10.138
- affected 5.15.61 – < 5.15.63
- affected 5.19.2 – < 5.19.4
References (7)
- https://git.kernel.org/stable/c/6f75057c21eab12c6ccb7f06f859641a6edfab99 (opens in a new tab)
- https://git.kernel.org/stable/c/5db5ce0f1963c6c8275719a80cb65e9c98d32726 (opens in a new tab)
- https://git.kernel.org/stable/c/ccb0a42d3f40c436295e0fef57ab613ae5b925a4 (opens in a new tab)
- https://git.kernel.org/stable/c/a868f771ee41c97a25a04b8c632a7f06689b307b (opens in a new tab)
- https://git.kernel.org/stable/c/1d9e75c3d8cdf7c96a94cb77450d4ee070279e6a (opens in a new tab)
- https://git.kernel.org/stable/c/90f195c01a2e8d8da6281791617e21109719c981 (opens in a new tab)
- https://git.kernel.org/stable/c/8d48562a2729742f767b0fdd994d6b2a56a49c63 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2022-50045)Record last updated .