Debian: CVE-2022-48940: linux -- security update

Debian: CVE-2022-48940: linux -- security update

Severity

5

CVSS

(AV:L/AC:L/Au:S/C:N/I:N/A:C)

Published

08/22/2024

Created

08/24/2024

Added

08/23/2024

Modified

01/28/2025

Description

In the Linux kernel, the following vulnerability has been resolved: bpf: Fix crash due to incorrect copy_map_value When both bpf_spin_lock and bpf_timer are present in a BPF map value, copy_map_value needs to skirt both objects when copying a value into and out of the map. However, the current code does not set both s_off and t_off in copy_map_value, which leads to a crash when e.g. bpf_spin_lock is placed in map value with bpf_timer, as bpf_map_update_elem call will be able to overwrite the other timer object. When the issue is not fixed, an overwriting can produce the following splat: [root@(none) bpf]# ./test_progs -t timer_crash [ 15.930339] bpf_testmod: loading out-of-tree module taints kernel. [ 16.037849] ================================================================== [ 16.038458] BUG: KASAN: user-memory-access in __pv_queued_spin_lock_slowpath+0x32b/0x520 [ 16.038944] Write of size 8 at addr 0000000000043ec0 by task test_progs/325 [ 16.039399] [ 16.039514] CPU: 0 PID: 325 Comm: test_progs Tainted: G OE 5.16.0+ #278 [ 16.039983] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ArchLinux 1.15.0-1 04/01/2014 [ 16.040485] Call Trace: [ 16.040645]<TASK> [ 16.040805]dump_stack_lvl+0x59/0x73 [ 16.041069]? __pv_queued_spin_lock_slowpath+0x32b/0x520 [ 16.041427]kasan_report.cold+0x116/0x11b [ 16.041673]? __pv_queued_spin_lock_slowpath+0x32b/0x520 [ 16.042040]__pv_queued_spin_lock_slowpath+0x32b/0x520 [ 16.042328]? memcpy+0x39/0x60 [ 16.042552]? pv_hash+0xd0/0xd0 [ 16.042785]? lockdep_hardirqs_off+0x95/0xd0 [ 16.043079]__bpf_spin_lock_irqsave+0xdf/0xf0 [ 16.043366]? bpf_get_current_comm+0x50/0x50 [ 16.043608]? jhash+0x11a/0x270 [ 16.043848]bpf_timer_cancel+0x34/0xe0 [ 16.044119]bpf_prog_c4ea1c0f7449940d_sys_enter+0x7c/0x81 [ 16.044500]bpf_trampoline_6442477838_0+0x36/0x1000 [ 16.044836]__x64_sys_nanosleep+0x5/0x140 [ 16.045119]do_syscall_64+0x59/0x80 [ 16.045377]? lock_is_held_type+0xe4/0x140 [ 16.045670]? irqentry_exit_to_user_mode+0xa/0x40 [ 16.046001]? mark_held_locks+0x24/0x90 [ 16.046287]? asm_exc_page_fault+0x1e/0x30 [ 16.046569]? asm_exc_page_fault+0x8/0x30 [ 16.046851]? lockdep_hardirqs_on+0x7e/0x100 [ 16.047137]entry_SYSCALL_64_after_hwframe+0x44/0xae [ 16.047405] RIP: 0033:0x7f9e4831718d [ 16.047602] Code: b4 0c 00 0f 05 eb a9 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d b3 6c 0c 00 f7 d8 64 89 01 48 [ 16.048764] RSP: 002b:00007fff488086b8 EFLAGS: 00000206 ORIG_RAX: 0000000000000023 [ 16.049275] RAX: ffffffffffffffda RBX: 00007f9e48683740 RCX: 00007f9e4831718d [ 16.049747] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007fff488086d0 [ 16.050225] RBP: 00007fff488086f0 R08: 00007fff488085d7 R09: 00007f9e4cb594a0 [ 16.050648] R10: 0000000000000000 R11: 0000000000000206 R12: 00007f9e484cde30 [ 16.051124] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 [ 16.051608]</TASK> [ 16.051762] ==================================================================

Solution(s)

• debian-upgrade-linux

References

• https://attackerkb.com/topics/cve-2022-48940
• CVE - 2022-48940