In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_api: Don't replay RTM_GETCHAIN in tc_ctl_chain(). If a netlink socket sends RTM_GETCHAIN requests repeatedly without recv()ing the responses, tc_ctl_chain() hogs CPU and triggers Hung Task splat. [0] As caught in the stack trace, netlink_attachskb() could confuse tc_ctl_chain() by returning -EAGAIN when the userspace netlink socket's receive buffer is full. The replay: label exists since commit 32a4f5ecd738 ("net: sched: introduce chain object to uapi") but was not used initially. Since commit 9f407f1768d3 ("net: sched: introduce chain templates"), the label is needed for RTM_NEWCHAIN because tcf_proto_lookup_ops() may release RTNL to call request_module(). However, the replay logic is unnecessary for RTM_GETCHAIN. Let's apply the replay logic only for RTM_NEWCHAIN. [0]: INFO: task repro:1018 is blocked on a mutex likely owned by task repro:1022. task:repro state:R running task ...

In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_api: Don't replay RTM_GETCHAIN in tc_ctl_chain(). If a netlink socket sends RTM_GETCHAIN requests repeatedly without recv()ing the responses, tc_ctl_chain() hogs CPU and triggers Hung Task splat. [0] As caught in the stack trace, netlink_attachskb() could confuse tc_ctl_chain() by returning -EAGAIN when the userspace netlink socket's receive buffer is full. The replay: label exists since commit 32a4f5ecd738 ("net: sched: introduce chain object to uapi") but was not used initially. Since commit 9f407f1768d3 ("net: sched: introduce chain templates"), the label is needed for RTM_NEWCHAIN because tcf_proto_lookup_ops() may release RTNL to call request_module(). However, the replay logic is unnecessary for RTM_GETCHAIN. Let's apply the replay logic only for RTM_NEWCHAIN. [0]: INFO: task repro:1018 is blocked on a mutex likely owned by task repro:1022. task:repro state:R running task stack:14...

In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_api: Don't replay RTM_GETCHAIN in tc_ctl_chain(). If a netlink socket sends RTM_GETCHAIN requests repeatedly without recv()ing the responses, tc_ctl_chain() hogs CPU and triggers Hung Task splat. [0] As caught in the stack trace, netlink_attachskb() could confuse tc_ctl_chain() by returning -EAGAIN when the userspace netlink socket's receive buffer is full. The replay: label exists since commit 32a4f5ecd738 ("net: sched: introduce chain object to uapi") but was not used initially. Since commit 9f407f1768d3 ("net: sched: introduce chain templates"), the label is needed for RTM_NEWCHAIN because tcf_proto_lookup_ops() may release RTNL to call request_module(). However, the replay logic is unnecessary for RTM_GETCHAIN. Let's apply the replay logic only for RTM_NEWCHAIN. [0]: INFO: task repro:1018 is blocked on a mutex likely owned by task repro:1022. task:repro state:R running task stack:14...

In the Linux kernel, the following vulnerability has been resolved: net/sched: cls_api: Don't replay RTM_GETCHAIN in tc_ctl_chain(). If a netlink socket sends RTM_GETCHAIN requests repeatedly without recv()ing the responses, tc_ctl_chain() hogs CPU and triggers Hung Task splat. [0] As caught in the stack trace, netlink_attachskb() could confuse tc_ctl_chain() by returning -EAGAIN when the userspace netlink socket's receive buffer is full. The replay: label exists since commit 32a4f5ecd738 ("net: sched: introduce chain object to uapi") but was not used initially. Since commit 9f407f1768d3 ("net: sched: introduce chain templates"), the label is needed for RTM_NEWCHAIN because tcf_proto_lookup_ops() may release RTNL to call request_module(). However, the replay logic is unnecessary for RTM_GETCHAIN. Let's apply the replay logic only for RTM_NEWCHAIN. [0]: INFO: task repro:1018 is blocked on a mutex likely owned by task repro:1022. task:repro state:R running task sta

net/sched: cls_api: Don't replay RTM_GETCHAIN in tc_ctl_chain().

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

ELSA-2026-500374: Unbreakable Enterprise kernel security update (IMPORTANT)