Bug 2439905 (CVE-2026-23203)
| Summary: | CVE-2026-23203 kernel: net: cpsw_new: Execute ndo_set_rx_mode callback in a work queue | ||
|---|---|---|---|
| Product: | [Other] Security Response | Reporter: | OSIDB Bzimport <bzimport> |
| Component: | vulnerability | Assignee: | Product Security DevOps Team <prodsec-dev> |
| Status: | NEW --- | QA Contact: | |
| Severity: | unspecified | Docs Contact: | |
| Priority: | unspecified | ||
| Version: | unspecified | Keywords: | Security |
| Target Milestone: | --- | ||
| Target Release: | --- | ||
| Hardware: | All | ||
| OS: | Linux | ||
| Whiteboard: | |||
| Fixed In Version: | Doc Type: | --- | |
| Doc Text: | 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: cpsw_new: Execute ndo_set_rx_mode callback in a work queue Commit 1767bb2d47b7 ("ipv6: mcast: Don't hold RTNL for IPV6_ADD_MEMBERSHIP and MCAST_JOIN_GROUP.") removed the RTNL lock for IPV6_ADD_MEMBERSHIP and MCAST_JOIN_GROUP operations. However, this change triggered the following call trace on my BeagleBone Black board: WARNING: net/8021q/vlan_core.c:236 at vlan_for_each+0x120/0x124, CPU#0: rpcbind/496 RTNL: assertion failed at net/8021q/vlan_core.c (236) Modules linked in: CPU: 0 UID: 997 PID: 496 Comm: rpcbind Not tainted 6.19.0-rc6-next-20260122-yocto-standard+ #8 PREEMPT Hardware name: Generic AM33XX (Flattened Device Tree) Call trace: unwind_backtrace from show_stack+0x28/0x2c show_stack from dump_stack_lvl+0x30/0x38 dump_stack_lvl from __warn+0xb8/0x11c __warn from warn_slowpath_fmt+0x130/0x194 warn_slowpath_fmt from vlan_for_each+0x120/0x124 vlan_for_each from cpsw_add_mc_addr+0x54/0xd8 cpsw_add_mc_addr from __hw_addr_ref_sync_dev+0xc4/0xec __hw_addr_ref_sync_dev from __dev_mc_add+0x78/0x88 __dev_mc_add from igmp6_group_added+0x84/0xec igmp6_group_added from __ipv6_dev_mc_inc+0x1fc/0x2f0 __ipv6_dev_mc_inc from __ipv6_sock_mc_join+0x124/0x1b4 __ipv6_sock_mc_join from do_ipv6_setsockopt+0x84c/0x1168 do_ipv6_setsockopt from ipv6_setsockopt+0x88/0xc8 ipv6_setsockopt from do_sock_setsockopt+0xe8/0x19c do_sock_setsockopt from __sys_setsockopt+0x84/0xac __sys_setsockopt from ret_fast_syscall+0x0/0x5 This trace occurs because vlan_for_each() is called within cpsw_ndo_set_rx_mode(), which expects the RTNL lock to be held. Since modifying vlan_for_each() to operate without the RTNL lock is not straightforward, and because ndo_set_rx_mode() is invoked both with and without the RTNL lock across different code paths, simply adding rtnl_lock() in cpsw_ndo_set_rx_mode() is not a viable solution. To resolve this issue, we opt to execute the actual processing within a work queue, following the approach used by the icssg-prueth driver.