CVE-2026-90209

s390/debug: Fix deadlock during unregister

N/A

Published: September 17, 2026 at 04:07 PM UTC

Updated: October 19, 2026 at 09:19 AM UTC

1 product affected across 1 vendorLinux Kernel

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Severity

N/A

Exploit prediction

EPSS 0.2%

Description

In the Linux kernel, the following vulnerability has been resolved: s390/debug: Fix deadlock during unregister Unregistering an s390dbf debug area while one of the associated debugfs files is being written to can cause a deadlock: $ echo >.../vmur/level $ rmmod vmur =================================================== debugfs write debugfs_file_get() debug_unregister() mutex_lock(debug_mutex) debugfs_remove() wait for debugfs_file_put() debug_file_ops.write() debug_input() mutex_lock(debug_mutex) ==> DEADLOCK Fix this by splitting debug_unregister() into an s390dbf and debugfs part, and running only the s390dbf part with debug_mutex locked.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Linux Kernel · Linux

90%

5.10.65 5.13.17 5.14.4 5.15 5.4.14686f9980909f31ab205323eeeb290fe3cbb4952b49372a82892c2caa6bccab9a4081166fa769699f8c68ba4a708fbd0efdc384cd29250bb292a45e559e234f66168f0d50c0d28154fb983a14e85c3c526fe5793e90d3f572a87ba67fe2f0e1679fdff14f8

Vendor states this is fixed in 183f8f6d64bb0510070c856b9927618c53014a7b (fixed)

Vendor states this is fixed in 445c31ac638fd1af203d79bdf25fc0cb3149fbbc (fixed)

Vendor states this is fixed in 45bb341d1b73eb293e0dd43d9b72bbc8b615d0ba (fixed)

Vendor states this is fixed in 54e1259b75d6402a1d0cfb822b9bb2c507e53dab (fixed)

Vendor states this is fixed in 5d83f3faa3fb7f23f298cfd40382611999de5d1d (fixed)

Vendor states this is fixed in a08b70ed2d1ec907353a72f15163b8e34ff4b2f8 (fixed)

Vendor states this is fixed in a214c3dacc779b2afcb0ac9c8001e45ee4ffb2ed (fixed)

Affected range stops below 5.11, so it looks safe — our inference, not a vendor statement

Affected range stops below 5.14, so it looks safe — our inference, not a vendor statement

Vendor states this is fixed in 5.15 (unaffected)

Vendor states this is fixed in 5.15.221 (unaffected)

Affected range stops below 5.5, so it looks safe — our inference, not a vendor statement