CVE-2022-49623 [High] | Out-of-bounds Read in Linux Kernel

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.

#	Date	Old EPSS score	New EPSS score	Delta (New - Old)
1	2026-05-05	0.08%	0.01%	-0.07%
2	2026-04-06	0.04%	0.08%	+0.03%
3	2025-02-27	—	0.04%	—

Date

Old EPSS score

New EPSS score

Delta (New - Old)

2026-05-05

0.08%

0.01%

-0.07%

2026-04-06

0.04%

0.08%

+0.03%

2025-02-27

—

0.04%

—

Base score	Version	Severity	Vector	Exploitability	Impact	Score source
7.1	3.1	HIGH	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	5.2	[email protected]
7.1	3.1	HIGH	`CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H` Click to expand Attack vector (AV:L) They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by. Attack complexity (AC:L) Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup. Privileges required (PR:L) A normal user session is enough; they don’t have to be admin. User interaction (UI:N) Nobody has to click “OK” or open a trap file; it can work without a victim helping. Scope (S:U) Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems. Confidentiality (C:H) Serious risk that confidential data gets exposed in a big way. Integrity (I:N) Data isn’t meaningfully altered or forged. Availability (A:H) Could take the service down hard or make it unusable for people who depend on it.	1.8	5.2	134c704f-9b21-4f2e-91b3-4a467353bcc0

Base score

Version

Severity

Vector

Exploitability

Impact

Score source

7.1

3.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

5.2

[email protected]

7.1

3.1

HIGH

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H Click to expand

Attack vector (AV:L): They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:L): Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L): A normal user session is enough; they don’t have to be admin.
User interaction (UI:N): Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U): Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H): Serious risk that confidential data gets exposed in a big way.
Integrity (I:N): Data isn’t meaningfully altered or forged.
Availability (A:H): Could take the service down hard or make it unusable for people who depend on it.

1.8

5.2

134c704f-9b21-4f2e-91b3-4a467353bcc0

OS Trackers for CVE-2022-49623

vendor	priority	summary	link
`debian`	not yet assigned	CVE-2022-49623 not yet assigned priority: Debian including 1 source packages (linux), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1.	https://security-tracker.debian.org/tracker/CVE-2022-49623
`redhat`	low	—	https://access.redhat.com/security/cve/CVE-2022-49623
`suse`	medium	—	https://www.suse.com/security/cve/CVE-2022-49623/
`ubuntu`	medium	CVE-2022-49623 medium priority: Ubuntu including 158 source packages (linux, linux-allwinner-5.19, …), 1551 status rows across 10 suites (bionic, focal, jammy, noble, oracular, plucky, questing, trusty, upstream, xenial): DNE 1145, ignored 150, released 114, not-affected 99, needed 42, needs-triage 1.	https://ubuntu.com/security/CVE-2022-49623

Affected software / configurations for CVE-2022-49623

Vendor	Product	Version	Raw CPE
linux	linux_kernel	< 5.15.56	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	>= 5.16, < 5.18.13	cpe:2.3:o:linux:linux_kernel::::::::
linux	linux_kernel	5.19	cpe:2.3:o:linux:linux_kernel:5.19:rc1::::::
linux	linux_kernel	5.19	cpe:2.3:o:linux:linux_kernel:5.19:rc2::::::
linux	linux_kernel	5.19	cpe:2.3:o:linux:linux_kernel:5.19:rc3::::::
linux	linux_kernel	5.19	cpe:2.3:o:linux:linux_kernel:5.19:rc4::::::

References for CVE-2022-49623

URL	Tags
https://git.kernel.org/stable/c/10f2cd373e65bcd3be8f3cdc71c330c25763dfd8	Patch
https://git.kernel.org/stable/c/19fc5bb93c6bbdce8292b4d7eed04e2fa118d2fe	Patch
https://git.kernel.org/stable/c/99d1c36bddd93919072b5a51a89297bbb5ad6a6f	Patch

URL

CVE-2022-49623 | powerpc/xive/spapr: correct bitmap allocation size

Exploit prediction scoring system (EPSS) score for CVE-2022-49623

Common vulnerability scoring system (CVSS) metrics for CVE-2022-49623

Weakness enumeration for CVE-2022-49623

OS Trackers for CVE-2022-49623

Affected software / configurations for CVE-2022-49623

References for CVE-2022-49623