Bug 2536799 (CVE-2026-90098) - CVE-2026-90098 kernel: net: sparx5: fix sleep in atomic context in MAC table access
Summary: CVE-2026-90098 kernel: net: sparx5: fix sleep in atomic context in MAC table ...
Keywords:
Status: NEW
Alias: CVE-2026-90098
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-09-17 19:34 UTC by OSIDB Bzimport
Modified: 2026-10-13 12:35 UTC (History)
17 users (show)

Fixed In Version:
Clone Of:
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Description OSIDB Bzimport 2026-09-17 19:34:28 UTC
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


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