CVE-2022-49623
CVE-2022-49623 is a high-severity vulnerability in Linux Linux Kernel with a CVSS 3.x base score of 7.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-125.
Key facts
- Severity: High (CVSS 3.x base score 7.1)
- EPSS exploit prediction: 0% (17th percentile)
- Actively exploited: Not listed in CISA KEV
- EU (EUVD) id: EUVD-2022-54609
- Weakness: CWE-125
- Affected product: Linux Linux Kernel
- Published:
- Last modified:
Description
In the Linux kernel, the following vulnerability has been resolved: powerpc/xive/spapr: correct bitmap allocation size kasan detects access beyond the end of the xibm->bitmap allocation: BUG: KASAN: slab-out-of-bounds in _find_first_zero_bit+0x40/0x140 Read of size 8 at addr c00000001d1d0118 by task swapper/0/1 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc2-00001-g90df023b36dd #28 Call Trace: [c00000001d98f770] [c0000000012baab8] dump_stack_lvl+0xac/0x108 (unreliable) [c00000001d98f7b0] [c00000000068faac] print_report+0x37c/0x710 [c00000001d98f880] [c0000000006902c0] kasan_report+0x110/0x354 [c00000001d98f950] [c000000000692324] __asan_load8+0xa4/0xe0 [c00000001d98f970] [c0000000011c6ed0] _find_first_zero_bit+0x40/0x140 [c00000001d98f9b0] [c0000000000dbfbc] xive_spapr_get_ipi+0xcc/0x260 [c00000001d98fa70] [c0000000000d6d28] xive_setup_cpu_ipi+0x1e8/0x450 [c00000001d98fb30] [c000000004032a20] pSeries_smp_probe+0x5c/0x118 [c00000001d98fb60] [c000000004018b44] smp_prepare_cpus+0x944/0x9ac [c00000001d98fc90] [c000000004009f9c] kernel_init_freeable+0x2d4/0x640 [c00000001d98fd90] [c0000000000131e8] kernel_init+0x28/0x1d0 [c00000001d98fe10] [c00000000000cd54] ret_from_kernel_thread+0x5c/0x64 Allocated by task 0: kasan_save_stack+0x34/0x70 __kasan_kmalloc+0xb4/0xf0 __kmalloc+0x268/0x540 xive_spapr_init+0x4d0/0x77c pseries_init_irq+0x40/0x27c init_IRQ+0x44/0x84 start_kernel+0x2a4/0x538 start_here_common+0x1c/0x20 The buggy address belongs to the object at c00000001d1d0118 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 0 bytes inside of 8-byte region [c00000001d1d0118, c00000001d1d0120) The buggy address belongs to the physical page: page:c00c000000074740 refcount:1 mapcount:0 mapping:0000000000000000 index:0xc00000001d1d0558 pfn:0x1d1d flags: 0x7ffff000000200(slab|node=0|zone=0|lastcpupid=0x7ffff) raw: 007ffff000000200 c00000001d0003c8 c00000001d0003c8 c00000001d010480 raw: c00000001d1d0558 0000000001e1000a 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: c00000001d1d0000: fc 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc c00000001d1d0080: fc fc 00 fc fc fc fc fc fc fc fc fc fc fc fc fc >c00000001d1d0100: fc fc fc 02 fc fc fc fc fc fc fc fc fc fc fc fc ^ c00000001d1d0180: fc fc fc fc 04 fc fc fc fc fc fc fc fc fc fc fc c00000001d1d0200: fc fc fc fc fc 04 fc fc fc fc fc fc fc fc fc fc This happens because the allocation uses the wrong unit (bits) when it should pass (BITS_TO_LONGS(count) * sizeof(long)) or equivalent. With small numbers of bits, the allocated object can be smaller than sizeof(long), which results in invalid accesses. Use bitmap_zalloc() to allocate and initialize the irq bitmap, paired with bitmap_free() for consistency.
Frequently asked questions
- What is CVE-2022-49623?
- In the Linux kernel, the following vulnerability has been resolved: powerpc/xive/spapr: correct bitmap allocation size kasan detects access beyond the end of the xibm->bitmap allocation: BUG: KASAN: slab-out-of-bounds in _find_first_zero_bit+0x40/0x140 Read of size 8 at addr c00000001d1d0118 by task swapper/0/1 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 5.19.0-rc2-00001-g90df023b36dd #28 Call Trace: [c00000001d98f770] [c0000000012baab8] dump_stack_lvl+0xac/0x108 (unreliable) [c00000001d98f7b0] [c00000000068faac] print_report+0x37c/0x710 [c00000001d98f880] [c0000000006902c0] kasan_report+0x110/0x354 [c00000001d98f950] [c000000000692324] __asan_load8+0xa4/0xe0 [c00000001d98f970] [c0000000011c6ed0] _find_first_zero_bit+0x40/0x140 [c00000001d98f9b0] [c0000000000dbfbc] xive_spapr_get_ipi+0xcc/0x260 [c00000001d98fa70] [c0000000000d6d28] xive_setup_cpu_ipi+0x1e8/0x450 [c00000001d98fb30] [c000000004032a20] pSeries_smp_probe+0x5c/0x118 [c00000001d98fb60] [c000000004018b44] smp_prepare_cpus+0x944/0x9ac [c00000001d98fc90] [c000000004009f9c] kernel_init_freeable+0x2d4/0x640 [c00000001d98fd90] [c0000000000131e8] kernel_init+0x28/0x1d0 [c00000001d98fe10] [c00000000000cd54] ret_from_kernel_thread+0x5c/0x64 Allocated by task 0: kasan_save_stack+0x34/0x70 __kasan_kmalloc+0xb4/0xf0 __kmalloc+0x268/0x540 xive_spapr_init+0x4d0/0x77c pseries_init_irq+0x40/0x27c init_IRQ+0x44/0x84 start_kernel+0x2a4/0x538 start_here_common+0x1c/0x20 The buggy address belongs to the object at c00000001d1d0118 which belongs to the cache kmalloc-8 of size 8 The buggy address is located 0 bytes inside of 8-byte region [c00000001d1d0118, c00000001d1d0120) The buggy address belongs to the physical page: page:c00c000000074740 refcount:1 mapcount:0 mapping:0000000000000000 index:0xc00000001d1d0558 pfn:0x1d1d flags: 0x7ffff000000200(slab|node=0|zone=0|lastcpupid=0x7ffff) raw: 007ffff000000200 c00000001d0003c8 c00000001d0003c8 c00000001d010480 raw: c00000001d1d0558 0000000001e1000a 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: c00000001d1d0000: fc 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc c00000001d1d0080: fc fc 00 fc fc fc fc fc fc fc fc fc fc fc fc fc >c00000001d1d0100: fc fc fc 02 fc fc fc fc fc fc fc fc fc fc fc fc ^ c00000001d1d0180: fc fc fc fc 04 fc fc fc fc fc fc fc fc fc fc fc c00000001d1d0200: fc fc fc fc fc 04 fc fc fc fc fc fc fc fc fc fc This happens because the allocation uses the wrong unit (bits) when it should pass (BITS_TO_LONGS(count) * sizeof(long)) or equivalent. With small numbers of bits, the allocated object can be smaller than sizeof(long), which results in invalid accesses. Use bitmap_zalloc() to allocate and initialize the irq bitmap, paired with bitmap_free() for consistency.
- How severe is CVE-2022-49623?
- CVE-2022-49623 has a CVSS 3.x base score of 7.1, rated high severity. It is exploitable over local access with low attack complexity, requires low privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability high.
- Is CVE-2022-49623 being actively exploited?
- It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (17th percentile), an estimate of the probability of exploitation in the next 30 days.
- What products are affected by CVE-2022-49623?
- CVE-2022-49623 primarily affects Linux Linux Kernel. In total, 5 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
- How do I fix CVE-2022-49623?
- Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
- Does CVE-2022-49623 have an EU (EUVD) identifier?
- Yes. CVE-2022-49623 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2022-54609.
- When was CVE-2022-49623 published?
- CVE-2022-49623 was published on 2025-02-26 and last updated on 2026-06-17.
References
- https://git.kernel.org/stable/c/10f2cd373e65bcd3be8f3cdc71c330c25763dfd8
- https://git.kernel.org/stable/c/19fc5bb93c6bbdce8292b4d7eed04e2fa118d2fe
- https://git.kernel.org/stable/c/99d1c36bddd93919072b5a51a89297bbb5ad6a6f
Affected products (5)
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.19:rc1:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.19:rc2:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.19:rc3:*:*:*:*:*:*
- cpe:2.3:o:linux:linux_kernel:5.19:rc4:*:*:*:*:*:*
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