In the Linux kernel, the following vulnerability has been resolved:
bpf: Cancel the running bpf_timer through kworker for PREEMPT_RT
During the update procedure, when overwrite element in a pre-allocated htab, the freeing of old_element is protected by the bucket lock. The reason why the bucket lock is necessary is that the old_element has already been stashed in htab->extra_elems after alloc_htab_elem() returns. If freeing the old_element after the bucket lock is unlocked, the stashed element may be reused by concurrent update procedure and the freeing of old_element will run concurrently with the reuse of the old_element. However, the invocation of check_and_free_fields() may acquire a spin-lock which violates the lockdep rule because its caller has already held a raw-spin-lock (bucket lock). The following warning will be reported when such race happens:
BUG: scheduling while atomic: test_progs/676/0x00000003 3 locks held by test_progs/676: #0: ffffffff864b0240 (rcu_read_lock_trace){….}-{0:0}, at: bpf_prog_test_run_syscall+0x2c0/0x830 #1: ffff88810e961188 (&htab->lockdep_key){….}-{2:2}, at: htab_map_update_elem+0x306/0x1500 #2: ffff8881f4eac1b8 (&base->softirq_expiry_lock){….}-{2:2}, at: hrtimer_cancel_wait_running+0xe9/0x1b0 Modules linked in: bpf_testmod(O) Preemption disabled at: [] htab_map_update_elem+0x293/0x1500 CPU: 0 UID: 0 PID: 676 Comm: test_progs Tainted: G … 6.12.0+ #11 Tainted: [W]=WARN, [O]=OOT_MODULE Hardware name: QEMU Standard PC (i440FX + PIIX, 1996)… Call Trace: dump_stack_lvl+0x57/0x70 dump_stack+0x10/0x20 __schedule_bug+0x120/0x170 __schedule+0x300c/0x4800 schedule_rtlock+0x37/0x60 rtlock_slowlock_locked+0x6d9/0x54c0 rt_spin_lock+0x168/0x230 hrtimer_cancel_wait_running+0xe9/0x1b0 hrtimer_cancel+0x24/0x30 bpf_timer_delete_work+0x1d/0x40 bpf_timer_cancel_and_free+0x5e/0x80 bpf_obj_free_fields+0x262/0x4a0 check_and_free_fields+0x1d0/0x280 htab_map_update_elem+0x7fc/0x1500 bpf_prog_9f90bc20768e0cb9_overwrite_cb+0x3f/0x43 bpf_prog_ea601c4649694dbd_overwrite_timer+0x5d/0x7e bpf_prog_test_run_syscall+0x322/0x830 __sys_bpf+0x135d/0x3ca0 __x64_sys_bpf+0x75/0xb0 x64_sys_call+0x1b5/0xa10 do_syscall_64+0x3b/0xc0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 …
It seems feasible to break the reuse and refill of per-cpu extra_elems into two independent parts: reuse the per-cpu extra_elems with bucket lock being held and refill the old_element as per-cpu extra_elems after the bucket lock is unlocked. However, it will make the concurrent overwrite procedures on the same CPU return unexpected -E2BIG error when the map is full.
Therefore, the patch fixes the lock problem by breaking the cancelling of bpf_timer into two steps for PREEMPT_RT:
It is a bit hard to decide the right fix tag. One reason is that the problem depends on PREEMPT_RT which is enabled in v6.12. Considering the softirq_expiry_lock lock exists since v5.4 and bpf_timer is introduced in v5.15, the bpf_timer commit is used in the fixes tag and an extra depends-on tag is added to state the dependency on PREEMPT_RT.
Depends-on: v6.12+ with PREEMPT_RT enabled
Name | Vendor | Start Version | End Version |
---|---|---|---|
Linux | Ubuntu | jammy | * |
Linux | Ubuntu | noble | * |
Linux | Ubuntu | oracular | * |
Linux | Ubuntu | upstream | * |
Linux-allwinner-5.19 | Ubuntu | jammy | * |
Linux-allwinner-5.19 | Ubuntu | upstream | * |
Linux-aws | Ubuntu | jammy | * |
Linux-aws | Ubuntu | noble | * |
Linux-aws | Ubuntu | oracular | * |
Linux-aws | Ubuntu | upstream | * |
Linux-aws-5.0 | Ubuntu | bionic | * |
Linux-aws-5.0 | Ubuntu | esm-infra/bionic | * |
Linux-aws-5.0 | Ubuntu | upstream | * |
Linux-aws-5.11 | Ubuntu | focal | * |
Linux-aws-5.11 | Ubuntu | upstream | * |
Linux-aws-5.13 | Ubuntu | focal | * |
Linux-aws-5.13 | Ubuntu | upstream | * |
Linux-aws-5.15 | Ubuntu | focal | * |
Linux-aws-5.15 | Ubuntu | upstream | * |
Linux-aws-5.19 | Ubuntu | jammy | * |
Linux-aws-5.19 | Ubuntu | upstream | * |
Linux-aws-5.3 | Ubuntu | bionic | * |
Linux-aws-5.3 | Ubuntu | esm-infra/bionic | * |
Linux-aws-5.3 | Ubuntu | upstream | * |
Linux-aws-5.4 | Ubuntu | upstream | * |
Linux-aws-5.8 | Ubuntu | focal | * |
Linux-aws-5.8 | Ubuntu | upstream | * |
Linux-aws-6.2 | Ubuntu | jammy | * |
Linux-aws-6.2 | Ubuntu | upstream | * |
Linux-aws-6.5 | Ubuntu | jammy | * |
Linux-aws-6.5 | Ubuntu | upstream | * |
Linux-aws-6.8 | Ubuntu | jammy | * |
Linux-aws-6.8 | Ubuntu | upstream | * |
Linux-aws-fips | Ubuntu | fips-preview/jammy | * |
Linux-aws-fips | Ubuntu | fips-updates/jammy | * |
Linux-aws-fips | Ubuntu | trusty | * |
Linux-aws-fips | Ubuntu | upstream | * |
Linux-aws-fips | Ubuntu | xenial | * |
Linux-aws-hwe | Ubuntu | upstream | * |
Linux-azure | Ubuntu | bionic | * |
Linux-azure | Ubuntu | esm-infra/bionic | * |
Linux-azure | Ubuntu | jammy | * |
Linux-azure | Ubuntu | noble | * |
Linux-azure | Ubuntu | oracular | * |
Linux-azure | Ubuntu | upstream | * |
Linux-azure-4.15 | Ubuntu | upstream | * |
Linux-azure-5.11 | Ubuntu | focal | * |
Linux-azure-5.11 | Ubuntu | upstream | * |
Linux-azure-5.13 | Ubuntu | focal | * |
Linux-azure-5.13 | Ubuntu | upstream | * |
Linux-azure-5.15 | Ubuntu | focal | * |
Linux-azure-5.15 | Ubuntu | upstream | * |
Linux-azure-5.19 | Ubuntu | jammy | * |
Linux-azure-5.19 | Ubuntu | upstream | * |
Linux-azure-5.3 | Ubuntu | bionic | * |
Linux-azure-5.3 | Ubuntu | esm-infra/bionic | * |
Linux-azure-5.3 | Ubuntu | upstream | * |
Linux-azure-5.4 | Ubuntu | upstream | * |
Linux-azure-5.8 | Ubuntu | focal | * |
Linux-azure-5.8 | Ubuntu | upstream | * |
Linux-azure-6.2 | Ubuntu | jammy | * |
Linux-azure-6.2 | Ubuntu | upstream | * |
Linux-azure-6.5 | Ubuntu | jammy | * |
Linux-azure-6.5 | Ubuntu | upstream | * |
Linux-azure-6.8 | Ubuntu | jammy | * |
Linux-azure-6.8 | Ubuntu | upstream | * |
Linux-azure-edge | Ubuntu | bionic | * |
Linux-azure-edge | Ubuntu | esm-infra/bionic | * |
Linux-azure-edge | Ubuntu | upstream | * |
Linux-azure-fde | Ubuntu | focal | * |
Linux-azure-fde | Ubuntu | jammy | * |
Linux-azure-fde | Ubuntu | upstream | * |
Linux-azure-fde-5.15 | Ubuntu | focal | * |
Linux-azure-fde-5.15 | Ubuntu | upstream | * |
Linux-azure-fde-5.19 | Ubuntu | jammy | * |
Linux-azure-fde-5.19 | Ubuntu | upstream | * |
Linux-azure-fde-6.2 | Ubuntu | jammy | * |
Linux-azure-fde-6.2 | Ubuntu | upstream | * |
Linux-azure-fips | Ubuntu | fips-preview/jammy | * |
Linux-azure-fips | Ubuntu | fips-updates/jammy | * |
Linux-azure-fips | Ubuntu | trusty | * |
Linux-azure-fips | Ubuntu | upstream | * |
Linux-azure-fips | Ubuntu | xenial | * |
Linux-bluefield | Ubuntu | bluefield/jammy | * |
Linux-bluefield | Ubuntu | upstream | * |
Linux-fips | Ubuntu | fips-preview/jammy | * |
Linux-fips | Ubuntu | fips-updates/jammy | * |
Linux-fips | Ubuntu | upstream | * |
Linux-gcp | Ubuntu | bionic | * |
Linux-gcp | Ubuntu | esm-infra/bionic | * |
Linux-gcp | Ubuntu | jammy | * |
Linux-gcp | Ubuntu | noble | * |
Linux-gcp | Ubuntu | oracular | * |
Linux-gcp | Ubuntu | upstream | * |
Linux-gcp-4.15 | Ubuntu | upstream | * |
Linux-gcp-5.11 | Ubuntu | focal | * |
Linux-gcp-5.11 | Ubuntu | upstream | * |
Linux-gcp-5.13 | Ubuntu | focal | * |
Linux-gcp-5.13 | Ubuntu | upstream | * |
Linux-gcp-5.15 | Ubuntu | focal | * |
Linux-gcp-5.15 | Ubuntu | upstream | * |
Linux-gcp-5.19 | Ubuntu | jammy | * |
Linux-gcp-5.19 | Ubuntu | upstream | * |
Linux-gcp-5.3 | Ubuntu | bionic | * |
Linux-gcp-5.3 | Ubuntu | esm-infra/bionic | * |
Linux-gcp-5.3 | Ubuntu | upstream | * |
Linux-gcp-5.4 | Ubuntu | upstream | * |
Linux-gcp-5.8 | Ubuntu | focal | * |
Linux-gcp-5.8 | Ubuntu | upstream | * |
Linux-gcp-6.2 | Ubuntu | jammy | * |
Linux-gcp-6.2 | Ubuntu | upstream | * |
Linux-gcp-6.5 | Ubuntu | jammy | * |
Linux-gcp-6.5 | Ubuntu | upstream | * |
Linux-gcp-6.8 | Ubuntu | jammy | * |
Linux-gcp-6.8 | Ubuntu | upstream | * |
Linux-gcp-fips | Ubuntu | fips-preview/jammy | * |
Linux-gcp-fips | Ubuntu | fips-updates/jammy | * |
Linux-gcp-fips | Ubuntu | trusty | * |
Linux-gcp-fips | Ubuntu | upstream | * |
Linux-gcp-fips | Ubuntu | xenial | * |
Linux-gke | Ubuntu | focal | * |
Linux-gke | Ubuntu | jammy | * |
Linux-gke | Ubuntu | noble | * |
Linux-gke | Ubuntu | upstream | * |
Linux-gke | Ubuntu | xenial | * |
Linux-gke-4.15 | Ubuntu | bionic | * |
Linux-gke-4.15 | Ubuntu | esm-infra/bionic | * |
Linux-gke-4.15 | Ubuntu | upstream | * |
Linux-gke-5.15 | Ubuntu | focal | * |
Linux-gke-5.15 | Ubuntu | upstream | * |
Linux-gke-5.4 | Ubuntu | bionic | * |
Linux-gke-5.4 | Ubuntu | esm-infra/bionic | * |
Linux-gke-5.4 | Ubuntu | upstream | * |
Linux-gkeop | Ubuntu | focal | * |
Linux-gkeop | Ubuntu | jammy | * |
Linux-gkeop | Ubuntu | noble | * |
Linux-gkeop | Ubuntu | upstream | * |
Linux-gkeop-5.15 | Ubuntu | focal | * |
Linux-gkeop-5.15 | Ubuntu | upstream | * |
Linux-gkeop-5.4 | Ubuntu | bionic | * |
Linux-gkeop-5.4 | Ubuntu | esm-infra/bionic | * |
Linux-gkeop-5.4 | Ubuntu | upstream | * |
Linux-hwe | Ubuntu | bionic | * |
Linux-hwe | Ubuntu | esm-infra/bionic | * |
Linux-hwe | Ubuntu | upstream | * |
Linux-hwe-5.11 | Ubuntu | focal | * |
Linux-hwe-5.11 | Ubuntu | upstream | * |
Linux-hwe-5.13 | Ubuntu | focal | * |
Linux-hwe-5.13 | Ubuntu | upstream | * |
Linux-hwe-5.15 | Ubuntu | focal | * |
Linux-hwe-5.15 | Ubuntu | upstream | * |
Linux-hwe-5.19 | Ubuntu | jammy | * |
Linux-hwe-5.19 | Ubuntu | upstream | * |
Linux-hwe-5.4 | Ubuntu | upstream | * |
Linux-hwe-5.8 | Ubuntu | focal | * |
Linux-hwe-5.8 | Ubuntu | upstream | * |
Linux-hwe-6.11 | Ubuntu | noble | * |
Linux-hwe-6.11 | Ubuntu | upstream | * |
Linux-hwe-6.2 | Ubuntu | jammy | * |
Linux-hwe-6.2 | Ubuntu | upstream | * |
Linux-hwe-6.5 | Ubuntu | jammy | * |
Linux-hwe-6.5 | Ubuntu | upstream | * |
Linux-hwe-6.8 | Ubuntu | jammy | * |
Linux-hwe-6.8 | Ubuntu | upstream | * |
Linux-hwe-edge | Ubuntu | bionic | * |
Linux-hwe-edge | Ubuntu | esm-infra/bionic | * |
Linux-hwe-edge | Ubuntu | esm-infra/xenial | * |
Linux-hwe-edge | Ubuntu | upstream | * |
Linux-hwe-edge | Ubuntu | xenial | * |
Linux-ibm | Ubuntu | jammy | * |
Linux-ibm | Ubuntu | noble | * |
Linux-ibm | Ubuntu | upstream | * |
Linux-ibm-5.15 | Ubuntu | focal | * |
Linux-ibm-5.15 | Ubuntu | upstream | * |
Linux-ibm-5.4 | Ubuntu | upstream | * |
Linux-intel | Ubuntu | noble | * |
Linux-intel | Ubuntu | upstream | * |
Linux-intel-5.13 | Ubuntu | focal | * |
Linux-intel-5.13 | Ubuntu | upstream | * |
Linux-intel-iot-realtime | Ubuntu | realtime/jammy | * |
Linux-intel-iot-realtime | Ubuntu | upstream | * |
Linux-intel-iotg | Ubuntu | jammy | * |
Linux-intel-iotg | Ubuntu | upstream | * |
Linux-intel-iotg-5.15 | Ubuntu | focal | * |
Linux-intel-iotg-5.15 | Ubuntu | upstream | * |
Linux-iot | Ubuntu | upstream | * |
Linux-kvm | Ubuntu | jammy | * |
Linux-kvm | Ubuntu | upstream | * |
Linux-lowlatency | Ubuntu | jammy | * |
Linux-lowlatency | Ubuntu | noble | * |
Linux-lowlatency | Ubuntu | oracular | * |
Linux-lowlatency | Ubuntu | upstream | * |
Linux-lowlatency-hwe-5.15 | Ubuntu | focal | * |
Linux-lowlatency-hwe-5.15 | Ubuntu | upstream | * |
Linux-lowlatency-hwe-5.19 | Ubuntu | jammy | * |
Linux-lowlatency-hwe-5.19 | Ubuntu | upstream | * |
Linux-lowlatency-hwe-6.11 | Ubuntu | noble | * |
Linux-lowlatency-hwe-6.11 | Ubuntu | upstream | * |
Linux-lowlatency-hwe-6.2 | Ubuntu | jammy | * |
Linux-lowlatency-hwe-6.2 | Ubuntu | upstream | * |
Linux-lowlatency-hwe-6.5 | Ubuntu | jammy | * |
Linux-lowlatency-hwe-6.5 | Ubuntu | upstream | * |
Linux-lowlatency-hwe-6.8 | Ubuntu | jammy | * |
Linux-lowlatency-hwe-6.8 | Ubuntu | upstream | * |
Linux-lts-xenial | Ubuntu | upstream | * |
Linux-nvidia | Ubuntu | jammy | * |
Linux-nvidia | Ubuntu | noble | * |
Linux-nvidia | Ubuntu | upstream | * |
Linux-nvidia-6.2 | Ubuntu | jammy | * |
Linux-nvidia-6.2 | Ubuntu | upstream | * |
Linux-nvidia-6.5 | Ubuntu | jammy | * |
Linux-nvidia-6.5 | Ubuntu | upstream | * |
Linux-nvidia-6.8 | Ubuntu | jammy | * |
Linux-nvidia-6.8 | Ubuntu | upstream | * |
Linux-nvidia-lowlatency | Ubuntu | noble | * |
Linux-nvidia-lowlatency | Ubuntu | upstream | * |
Linux-nvidia-tegra | Ubuntu | jammy | * |
Linux-nvidia-tegra | Ubuntu | noble | * |
Linux-nvidia-tegra | Ubuntu | upstream | * |
Linux-nvidia-tegra-igx | Ubuntu | jammy | * |
Linux-nvidia-tegra-igx | Ubuntu | upstream | * |
Linux-oem | Ubuntu | bionic | * |
Linux-oem | Ubuntu | esm-infra/bionic | * |
Linux-oem | Ubuntu | upstream | * |
Linux-oem | Ubuntu | xenial | * |
Linux-oem-5.10 | Ubuntu | focal | * |
Linux-oem-5.10 | Ubuntu | upstream | * |
Linux-oem-5.13 | Ubuntu | focal | * |
Linux-oem-5.13 | Ubuntu | upstream | * |
Linux-oem-5.14 | Ubuntu | focal | * |
Linux-oem-5.14 | Ubuntu | upstream | * |
Linux-oem-5.17 | Ubuntu | jammy | * |
Linux-oem-5.17 | Ubuntu | upstream | * |
Linux-oem-5.6 | Ubuntu | focal | * |
Linux-oem-5.6 | Ubuntu | upstream | * |
Linux-oem-6.0 | Ubuntu | jammy | * |
Linux-oem-6.0 | Ubuntu | upstream | * |
Linux-oem-6.1 | Ubuntu | jammy | * |
Linux-oem-6.1 | Ubuntu | upstream | * |
Linux-oem-6.11 | Ubuntu | noble | * |
Linux-oem-6.11 | Ubuntu | upstream | * |
Linux-oem-6.5 | Ubuntu | jammy | * |
Linux-oem-6.5 | Ubuntu | upstream | * |
Linux-oem-6.8 | Ubuntu | noble | * |
Linux-oem-6.8 | Ubuntu | upstream | * |
Linux-oracle | Ubuntu | jammy | * |
Linux-oracle | Ubuntu | noble | * |
Linux-oracle | Ubuntu | oracular | * |
Linux-oracle | Ubuntu | upstream | * |
Linux-oracle-5.0 | Ubuntu | bionic | * |
Linux-oracle-5.0 | Ubuntu | esm-infra/bionic | * |
Linux-oracle-5.0 | Ubuntu | upstream | * |
Linux-oracle-5.11 | Ubuntu | focal | * |
Linux-oracle-5.11 | Ubuntu | upstream | * |
Linux-oracle-5.13 | Ubuntu | focal | * |
Linux-oracle-5.13 | Ubuntu | upstream | * |
Linux-oracle-5.15 | Ubuntu | focal | * |
Linux-oracle-5.15 | Ubuntu | upstream | * |
Linux-oracle-5.3 | Ubuntu | bionic | * |
Linux-oracle-5.3 | Ubuntu | esm-infra/bionic | * |
Linux-oracle-5.3 | Ubuntu | upstream | * |
Linux-oracle-5.4 | Ubuntu | upstream | * |
Linux-oracle-5.8 | Ubuntu | focal | * |
Linux-oracle-5.8 | Ubuntu | upstream | * |
Linux-oracle-6.5 | Ubuntu | jammy | * |
Linux-oracle-6.5 | Ubuntu | upstream | * |
Linux-oracle-6.8 | Ubuntu | jammy | * |
Linux-oracle-6.8 | Ubuntu | upstream | * |
Linux-raspi | Ubuntu | jammy | * |
Linux-raspi | Ubuntu | noble | * |
Linux-raspi | Ubuntu | oracular | * |
Linux-raspi | Ubuntu | upstream | * |
Linux-raspi-5.4 | Ubuntu | upstream | * |
Linux-raspi-realtime | Ubuntu | realtime/noble | * |
Linux-raspi-realtime | Ubuntu | upstream | * |
Linux-raspi2 | Ubuntu | bionic | * |
Linux-raspi2 | Ubuntu | focal | * |
Linux-raspi2 | Ubuntu | upstream | * |
Linux-raspi2 | Ubuntu | xenial | * |
Linux-realtime | Ubuntu | jammy | * |
Linux-realtime | Ubuntu | noble | * |
Linux-realtime | Ubuntu | oracular | * |
Linux-realtime | Ubuntu | realtime/jammy | * |
Linux-realtime | Ubuntu | realtime/noble | * |
Linux-realtime | Ubuntu | upstream | * |
Linux-riscv | Ubuntu | focal | * |
Linux-riscv | Ubuntu | jammy | * |
Linux-riscv | Ubuntu | noble | * |
Linux-riscv | Ubuntu | oracular | * |
Linux-riscv | Ubuntu | upstream | * |
Linux-riscv-5.11 | Ubuntu | focal | * |
Linux-riscv-5.11 | Ubuntu | upstream | * |
Linux-riscv-5.15 | Ubuntu | focal | * |
Linux-riscv-5.15 | Ubuntu | upstream | * |
Linux-riscv-5.19 | Ubuntu | jammy | * |
Linux-riscv-5.19 | Ubuntu | upstream | * |
Linux-riscv-5.8 | Ubuntu | focal | * |
Linux-riscv-5.8 | Ubuntu | upstream | * |
Linux-riscv-6.5 | Ubuntu | jammy | * |
Linux-riscv-6.5 | Ubuntu | upstream | * |
Linux-riscv-6.8 | Ubuntu | jammy | * |
Linux-riscv-6.8 | Ubuntu | upstream | * |
Linux-starfive-5.19 | Ubuntu | jammy | * |
Linux-starfive-5.19 | Ubuntu | upstream | * |
Linux-starfive-6.2 | Ubuntu | jammy | * |
Linux-starfive-6.2 | Ubuntu | upstream | * |
Linux-starfive-6.5 | Ubuntu | jammy | * |
Linux-starfive-6.5 | Ubuntu | upstream | * |
Linux-xilinx-zynqmp | Ubuntu | jammy | * |
Linux-xilinx-zynqmp | Ubuntu | upstream | * |