Bug 2536799 (CVE-2026-90098)
| Summary: | CVE-2026-90098 kernel: net: sparx5: fix sleep in atomic context in MAC table access | ||
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| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security DevOps Team <prodsec-dev> |
| Status: | NEW --- | QA Contact: | |
| Severity: | medium | Docs Contact: | |
| Priority: | medium | ||
| Version: | unspecified | CC: | akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers |
| Target Milestone: | --- | Keywords: | Security |
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | --- | |
| Doc Text: |
A flaw was found in the Linux kernel's `net: sparx5` driver. The `sparx5_set_rx_mode()` function attempts to acquire a mutex and poll a register while operating in an atomic context, which is not allowed. This improper operation can lead to a "sleep in atomic context" bug, causing system instability or a kernel panic. This issue ultimately results in a Denial of Service (DoS).
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Story Points: | --- |
| Clone Of: | Environment: | ||
| Last Closed: | Type: | --- | |
| Regression: | --- | Mount Type: | --- |
| Documentation: | --- | CRM: | |
| Verified Versions: | Category: | --- | |
| oVirt Team: | --- | RHEL 7.3 requirements from Atomic Host: | |
| Cloudforms Team: | --- | Target Upstream Version: | |
| Embargoed: | |||
In the Linux kernel, the following vulnerability has been resolved: net: sparx5: fix sleep in atomic context in MAC table access sparx5_set_rx_mode() runs with netif_addr_lock_bh held and iterates dev->mc via __dev_mc_sync(), which per address calls sparx5_mc_sync() / sparx5_mc_unsync() -> sparx5_mact_learn() / sparx5_mact_forget(). These take sparx5->lock, a mutex, and then poll the MAC access command register with readx_poll_timeout(). A mutex may block, which is not allowed from atomic context. Convert the driver to the new .ndo_set_rx_mode_async callback introduced in commit 3554b4345d85 ("net: introduce ndo_set_rx_mode_async and netdev_rx_mode_work"). The async callback is invoked from process context, so the mutex and sleeping completion poll can remain. Observed with CONFIG_PROVE_LOCKING, CONFIG_DEBUG_SPINLOCK, CONFIG_DEBUG_MUTEXES and CONFIG_DEBUG_ATOMIC_SLEEP enabled: BUG: sleeping function called from invalid context at kernel/locking/mutex.c:591 in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 217, name: ip preempt_count: 201, expected: 0 Call trace: __might_resched+0x144/0x248 __might_sleep+0x48/0x7c __mutex_lock+0x74/0x850 mutex_lock_nested+0x24/0x30 sparx5_mact_learn+0x78/0x100 sparx5_mc_sync+0x40/0x54 __hw_addr_sync_dev+0xc4/0x170 sparx5_set_rx_mode+0x4c/0x58 __dev_set_rx_mode+0x64/0xa4 __dev_open+0x1ec/0x26c