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

bpf: Fix KASAN use-after-free Read in compute_effective_progs

Syzbot found a Use After Free bug in compute_effective_progs(). The reproducer creates a number of BPF links, and causes a fault injected alloc to fail, while calling bpf_link_detach on them. Link detach triggers the link to be freed by bpf_link_free(), which calls __cgroup_bpf_detach() and update_effective_progs(). If the memory allocation in this function fails, the function restores the pointer to the bpf_cgroup_link on the cgroup list, but the memory gets freed just after it returns. After this, every subsequent call to update_effective_progs() causes this already deallocated pointer to be dereferenced in prog_list_length(), and triggers KASAN UAF error.

To fix this issue don't preserve the pointer to the prog or link in the list, but remove it and replace it with a dummy prog without shrinking the table. The subsequent call to __cgroup_bpf_detach() or __cgroup_bpf_detach() will correct it.

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

bpf: Fix KASAN use-after-free Read in compute_effective_progs

Syzbot found a Use After Free bug in compute_effective_progs(). The reproducer creates a number of BPF links, and causes a fault injected alloc to fail, while calling bpf_link_detach on them. Link detach triggers the link to be freed by bpf_link_free(), which calls __cgroup_bpf_detach() and update_effective_progs(). If the memory allocation in this function fails, the function restores the pointer to the bpf_cgroup_link on the cgroup list, but the memory gets freed just after it returns. After this, every subsequent call to update_effective_progs() causes this already deallocated pointer to be dereferenced in prog_list_length(), and triggers KASAN UAF error.

To fix this issue don't preserve the pointer to the prog or link in the list, but remove it and replace it with a dummy prog without shrinking the table. The subsequent call to __cgroup_bpf_detach() or __cgroup_bpf_detach() will correct it.

kernel: kernel pointer leak due to WARN_ON statement in video driver leads to local information disclosure kernel: use after free due to race condition in the video driver leads to local privilege escalation kernel: null pointer dereference in dlpar_parse_cc_property in arch/powerrc/platforms/pseries/dlpar.c causing denial of service kernel: use-after-free in drivers/bluetooth/hci_ldisc.c kernel: out-of-bounds access in function hclge_tm_schd_mode_vnet_base_cfg kernel: null-pointer dereference in drivers/net/fjes/fjes_main.c kernel: null pointer dereference in drivers/scsi/qla2xxx/qla_os.c kernel: memory leak in ccp_run_sha_cmd() function in drivers/crypto/ccp/ccp-ops.c kernel: memory leak in af9005_identify_state() function in drivers/media/usb/dvb-usb/af9005.c kernel: Denial Of Service in the __ipmi_bmc_register() function in drivers/char/ipmi/ipmi_msghandler.c kernel: A memory leak in the mwifiex_pcie_alloc_cmdrsp_buf() function in drivers/net/wireless/marvell/mwifiex/pcie.c allows to cause DoS kernel: memory leak in the crypto_report() function in crypto/crypto_user_base.c allows for DoS kernel: Two memory leaks in the rtl_usb_probe() function in drivers/net/wireless/realtek/rtlwifi/usb.c allow for a DoS kernel: A memory leak in the rtl8xxxu_submit_int_urb() function in drivers/net/wireless/realtek/rtl8xxxu/rtl8xxxu_core.c allows for a DoS kernel: A memory leak in the predicate_parse() function in kernel/trace/trace_events_filter.c allows for a DoS kernel: out-of-bounds…

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 94 more

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix KASAN use-after-free Read in compute_effective_progs Syzbot found a Use After Free bug in compute_effective_progs(). The reproducer creates a number of BPF links, and causes a fault injected alloc to fail, while calling bpf_link_detach on them. Link detach triggers the link to be freed by bpf_link_free(), which calls __cgroup_bpf_detach() and update_effective_progs(). If the memory allocation in this function fails, the function restores the pointer to the bpf_cgroup_link on the cgroup list, but the memory gets freed just after it returns. After this, every subsequent call to update_effective_progs() causes this already deallocated pointer to be dereferenced in prog_list_length(), and triggers KASAN UAF error. To fix this issue don't preserve the pointer to the prog or link in the list, but remove it and replace it with a dummy prog without shrinking the table. The subsequent call to __cgroup_bpf_detach() or __cgroup_bpf_detach() will correct it.

Ein lokaler Angreifer kann mehrere Schwachstellen in Linux Kernel ausnutzen, um einen Denial of Service Angriff durchzuführen.