Bug 2492341 (CVE-2026-53008)

Summary: CVE-2026-53008 kernel: ice: fix race condition in TX timestamp ring cleanup
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
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Doc Text:
A flaw was found in the Linux kernel. A race condition exists in the `ice` network driver's TX timestamp ring cleanup, specifically between the `ice_free_tx_tstamp_ring()` and `ice_tx_map()` functions. This vulnerability could allow a local attacker to trigger a null pointer dereference, leading to a system crash and a Denial of Service (DoS).
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-06-24 18:06:46 UTC
In the Linux kernel, the following vulnerability has been resolved:

ice: fix race condition in TX timestamp ring cleanup

Fix a race condition between ice_free_tx_tstamp_ring() and ice_tx_map()
that can cause a NULL pointer dereference.

ice_free_tx_tstamp_ring currently clears the ICE_TX_FLAGS_TXTIME flag
after NULLing the tstamp_ring. This could allow a concurrent ice_tx_map
call on another CPU to dereference the tstamp_ring, which could lead to
a NULL pointer dereference.

  CPU A:ice_free_tx_tstamp_ring() | CPU B:ice_tx_map()
  --------------------------------|---------------------------------
  tx_ring->tstamp_ring = NULL     |
                                  | ice_is_txtime_cfg() -> true
                                  | tstamp_ring = tx_ring->tstamp_ring
                                  | tstamp_ring->count  // NULL deref!
  flags &= ~ICE_TX_FLAGS_TXTIME   |

Fix by:
1. Reordering ice_free_tx_tstamp_ring() to clear the flag before
   NULLing the pointer, with smp_wmb() to ensure proper ordering.
2. Adding smp_rmb() in ice_tx_map() after the flag check to order the
   flag read before the pointer read, using READ_ONCE() for the
   pointer, and adding a NULL check as a safety net.
3. Converting tx_ring->flags from u8 to DECLARE_BITMAP() and using
   atomic bitops (set_bit(), clear_bit(), test_bit()) for all flag
   operations throughout the driver:
   - ICE_TX_RING_FLAGS_XDP
   - ICE_TX_RING_FLAGS_VLAN_L2TAG1
   - ICE_TX_RING_FLAGS_VLAN_L2TAG2
   - ICE_TX_RING_FLAGS_TXTIME