Affected: Alpaquita:25: linux-lts, Alpaquita:stream: linux-lts

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

bpf,lsm: Drop bpf_prog_free from sleepable_lsm_hooks

__bpf_prog_put_rcu() is the call_rcu() callback for non-sleepable programs. security_bpf_prog_free() called from there fires bpf_prog_free in softirq; if a sleepable LSM prog is attached to that hook, might_fault() BUGs:

BUG: sleeping function called from invalid context in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 5038 preempt_count: 101, expected: 0 Call Trace: <IRQ> __bpf_prog_enter_sleepable+0x1cd/0x320 kernel/bpf/trampoline.c:1255 bpf_trampoline_6442549705+0x53/0xd7 security_bpf_prog_free+0xde/0x130 security/security.c:5465 __bpf_prog_put_rcu+0xab/0xd0 kernel/bpf/syscall.c:2365 rcu_do_batch kernel/rcu/tree.c:2617 [inline] handle_softirqs+0x236/0x800 kernel/softirq.c:622 </IRQ>

The call_rcu/call_rcu_tasks_trace split reflects the freed program's sleepability, not that of any attached observer.

security_bpf_prog_free() also frees prog->aux->security, which has to stay after the grace period, so drop bpf_prog_free from sleepable_lsm_hooks rather than move the call. Non-sleepable observers still run there.

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

bpf,lsm: Drop bpf_prog_free from sleepable_lsm_hooks

__bpf_prog_put_rcu() is the call_rcu() callback for non-sleepable programs. security_bpf_prog_free() called from there fires bpf_prog_free in softirq; if a sleepable LSM prog is attached to that hook, might_fault() BUGs:

BUG: sleeping function called from invalid context in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 5038 preempt_count: 101, expected: 0 Call Trace: <IRQ> __bpf_prog_enter_sleepable+0x1cd/0x320 kernel/bpf/trampoline.c:1255 bpf_trampoline_6442549705+0x53/0xd7 security_bpf_prog_free+0xde/0x130 security/security.c:5465 __bpf_prog_put_rcu+0xab/0xd0 kernel/bpf/syscall.c:2365 rcu_do_batch kernel/rcu/tree.c:2617 [inline] handle_softirqs+0x236/0x800 kernel/softirq.c:622 </IRQ>

The call_rcu/call_rcu_tasks_trace split reflects the freed program's sleepability, not that of any attached observer.

security_bpf_prog_free() also frees prog->aux->security, which has to stay after the grace period, so drop bpf_prog_free from sleepable_lsm_hooks rather than move the call. Non-sleepable observers still run there.

kernel-devel-7.2.7-1.1 on GA media

Affected: Ubuntu:16.04:LTS: linux-hwe-edge, Ubuntu:18.04:LTS: linux-aws-5.0, Ubuntu:18.04:LTS: linux-aws-5.3, Ubuntu:18.04:LTS: linux-azure, Ubuntu:18.04:LTS: linux-azure-5.3, Ubuntu:18.04:LTS: linux-azure-edge, Ubuntu:18.04:LTS: linux-gcp, Ubuntu:18.04:LTS: linux-gcp-5.3, Ubuntu:18.04:LTS: linux-gke-4.15, Ubuntu:18.04:LTS: linux-gke-5.4 and 120 more

In the Linux kernel, the following vulnerability has been resolved: bpf,lsm: Drop bpf_prog_free from sleepable_lsm_hooks __bpf_prog_put_rcu() is the call_rcu() callback for non-sleepable programs. security_bpf_prog_free() called from there fires bpf_prog_free in softirq; if a sleepable LSM prog is attached to that hook, might_fault() BUGs: BUG: sleeping function called from invalid context in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 5038 preempt_count: 101, expected: 0 Call Trace: <IRQ> __bpf_prog_enter_sleepable+0x1cd/0x320 kernel/bpf/trampoline.c:1255 bpf_trampoline_6442549705+0x53/0xd7 security_bpf_prog_free+0xde/0x130 security/security.c:5465 __bpf_prog_put_rcu+0xab/0xd0 kernel/bpf/syscall.c:2365 rcu_do_batch kernel/rcu/tree.c:2617 [inline] handle_softirqs+0x236/0x800 kernel/softirq.c:622 </IRQ> The call_rcu/call_rcu_tasks_trace split reflects the freed program's sleepability, not that of any attached observer. security_bpf_prog_free() also frees prog->aux->security, which has to stay after the grace period, so drop bpf_prog_free from sleepable_lsm_hooks rather than move the call. Non-sleepable observers still run there.

Ein Angreifer kann mehrere Schwachstellen im Linux Kernel möglicherweise ausnutzen, um Berechtigungen zu erweitern, Sicherheitsmaßnahmen zu umgehen, Daten offenzulegen oder zu manipulieren, den Speicher zu beschädigen, Denial-of-Service-Zustände zu verursachen oder andere, nicht näher spezifizierte Angriffe durchzuführen.