net/iucv: fix locking in .getsockopt

Summary

In the Linux kernel, the following vulnerability has been resolved: net/iucv: fix locking in .getsockopt Mirror iucv_sock_setsockopt() and wrap the whole switch in lock_sock()/release_sock(). The pre-existing SO_MSGLIMIT-only lock becomes redundant and is removed. Any AF_IUCV HIPER user can potentially crash the kernel by racing recvmsg() with getsockopt(SO_MSGSIZE): the SO_MSGSIZE arm dereferences iucv->hs_dev->mtu after iucv_sock_close() (called from the racing recvmsg()) has set hs_dev to NULL, producing a NULL pointer dereference oops.

Timeline

1. Jul 19, 2026, 2:56 PM UTCCVE published
2. Oct 16, 2026, 3:35 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: total

3. Oct 19, 2026, 8:18 PM UTCRecord last updated

Affected versions

• Linux Linux

  From 51363b8751a673a00ad48eea895266396d53fa52 · fixed in 884eb247b74d86db97e3a37f0d6fc8e1e83590dd; From 51363b8751a673a00ad48eea895266396d53fa52 · fixed in 45bb8de8c95d8899f4b8f61bd9bceb8132af73cb; From 51363b8751a673a00ad48eea895266396d53fa52 · fixed in 1fc30bd4e55e2dd622d2d366cecd732c1841bbee; From 51363b8751a673a00ad48eea895266396d53fa52 · fixed in cd691beafea0dd779e69e81ccc26b0ab50efcb5e; From 51363b8751a673a00ad48eea895266396d53fa52 · fixed in 6e792b8dd3002bbc4136745928a9605df1a72b8a; From 51363b8751a673a00ad48eea895266396d53fa52 · fixed in 9817369243380e287ebe5525411557eaa3aa2a79; From 51363b8751a673a00ad48eea895266396d53fa52 · fixed in 69554adc7a6fa04ede3ad7512321d83748e3c920; From 51363b8751a673a00ad48eea895266396d53fa52 · fixed in 3589d20a666caf30ad100c960a2de7de390fce88

• Linux Linux

  3.4

• KernelLinux

  From 3.4.0 · fixed in 5.10.259; From 5.11.0 · fixed in 5.15.210; From 5.16.0 · fixed in 6.1.176; From 6.2.0 · fixed in 6.6.143; From 6.7.0 · fixed in 6.12.93; From 6.13.0 · fixed in 6.18.35; From 6.19.0 · fixed in 7.0.12

References 8