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Vulnerability Change Records for CVE-2026-52939

Change History

New CVE Received from kernel.org 6/24/2026 4:16:24 AM

Action Type Old Value New Value
Added Description

                  
                
              
In the Linux kernel, the following vulnerability has been resolved:

net/rds: fix NULL deref in rds_ib_send_cqe_handler() on masked atomic completion

rds_ib_xmit_atomic() always programs a masked atomic opcode
(IB_WR_MASKED_ATOMIC_CMP_AND_SWP or IB_WR_MASKED_ATOMIC_FETCH_AND_ADD)
for every RDS atomic cmsg.  But the completion-side switch in
rds_ib_send_unmap_op() only handles the non-masked opcodes, so a masked
atomic completion falls through to default and returns rm == NULL while
send->s_op is left set.  rds_ib_send_cqe_handler() then dereferences the
NULL rm via rm->m_final_op, oopsing in softirq context.  An unprivileged
AF_RDS sendmsg() of an atomic cmsg over an active RDS/IB connection
triggers it; on hardware that natively accepts masked atomics (mlx4,
mlx5) no extra setup is needed.

  RDS/IB: rds_ib_send_unmap_op: unexpected opcode 0xd in WR!
  Oops: general protection fault [#1] SMP KASAN
  KASAN: null-ptr-deref in range [0x0000000000000190-0x0000000000000197]
  RIP: rds_ib_send_cqe_handler+0x25c/0xb10 (net/rds/ib_send.c:282)
  Call Trace:
   <IRQ>
   rds_ib_send_cqe_handler (net/rds/ib_send.c:282)
   poll_scq (net/rds/ib_cm.c:274)
   rds_ib_tasklet_fn_send (net/rds/ib_cm.c:294)
   tasklet_action_common (kernel/softirq.c:943)
   handle_softirqs (kernel/softirq.c:573)
   run_ksoftirqd (kernel/softirq.c:479)
   </IRQ>
  Kernel panic - not syncing: Fatal exception in interrupt

Handle the masked atomic opcodes in the same case as the non-masked
ones: they map to the same struct rds_message.atomic union member, so
the existing container_of()/rds_ib_send_unmap_atomic() body is correct
for them.
Added Reference

                  
                
              
https://git.kernel.org/stable/c/0f22412a2f4fbbe0251c132abee045d15a90e5b6
Added Reference

                  
                
              
https://git.kernel.org/stable/c/0f7baa82a24813cdad0b06a6f8f07e4824af5ed5
Added Reference

                  
                
              
https://git.kernel.org/stable/c/34080db3e70ddf94c38512ad2331e3c3afca6cc1
Added Reference

                  
                
              
https://git.kernel.org/stable/c/4dd262f875e87653df50b138de1390ab0628e6b7
Added Reference

                  
                
              
https://git.kernel.org/stable/c/4fd34669558085bcb589aa2078a13b0ca79e360d
Added Reference

                  
                
              
https://git.kernel.org/stable/c/6e4615164d185a26badb2f376a2449f4d174a5f0
Added Reference

                  
                
              
https://git.kernel.org/stable/c/a0148342badd8c9b2e46551766a27cb76c82e715
Added Reference

                  
                
              
https://git.kernel.org/stable/c/dcf458120add64c96a6ef5cf719340453f6e6abf
Added Affected

                  
                
              
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