Out-of-bounds Write Affecting kernel-debug-uki-virt package, versions *
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-RHEL9-KERNELDEBUGUKIVIRT-7834372
- published27 Aug 2024
- disclosed26 Aug 2024
Introduced: 26 Aug 2024
CVE-2024-43910 (opens in a new tab)How to fix?
There is no fixed version for RHEL:9 kernel-debug-uki-virt.
NVD Description
Note: Versions mentioned in the description apply only to the upstream kernel-debug-uki-virt package and not the kernel-debug-uki-virt package as distributed by RHEL.
See How to fix? for RHEL:9 relevant fixed versions and status.
In the Linux kernel, the following vulnerability has been resolved:
bpf: add missing check_func_arg_reg_off() to prevent out-of-bounds memory accesses
Currently, it's possible to pass in a modified CONST_PTR_TO_DYNPTR to a global function as an argument. The adverse effects of this is that BPF helpers can continue to make use of this modified CONST_PTR_TO_DYNPTR from within the context of the global function, which can unintentionally result in out-of-bounds memory accesses and therefore compromise overall system stability i.e.
[ 244.157771] BUG: KASAN: slab-out-of-bounds in bpf_dynptr_data+0x137/0x140 [ 244.161345] Read of size 8 at addr ffff88810914be68 by task test_progs/302 [ 244.167151] CPU: 0 PID: 302 Comm: test_progs Tainted: G O E 6.10.0-rc3-00131-g66b586715063 #533 [ 244.174318] Call Trace: [ 244.175787] <TASK> [ 244.177356] dump_stack_lvl+0x66/0xa0 [ 244.179531] print_report+0xce/0x670 [ 244.182314] ? __virt_addr_valid+0x200/0x3e0 [ 244.184908] kasan_report+0xd7/0x110 [ 244.187408] ? bpf_dynptr_data+0x137/0x140 [ 244.189714] ? bpf_dynptr_data+0x137/0x140 [ 244.192020] bpf_dynptr_data+0x137/0x140 [ 244.194264] bpf_prog_b02a02fdd2bdc5fa_global_call_bpf_dynptr_data+0x22/0x26 [ 244.198044] bpf_prog_b0fe7b9d7dc3abde_callback_adjust_bpf_dynptr_reg_off+0x1f/0x23 [ 244.202136] bpf_user_ringbuf_drain+0x2c7/0x570 [ 244.204744] ? 0xffffffffc0009e58 [ 244.206593] ? __pfx_bpf_user_ringbuf_drain+0x10/0x10 [ 244.209795] bpf_prog_33ab33f6a804ba2d_user_ringbuf_callback_const_ptr_to_dynptr_reg_off+0x47/0x4b [ 244.215922] bpf_trampoline_6442502480+0x43/0xe3 [ 244.218691] __x64_sys_prlimit64+0x9/0xf0 [ 244.220912] do_syscall_64+0xc1/0x1d0 [ 244.223043] entry_SYSCALL_64_after_hwframe+0x77/0x7f [ 244.226458] RIP: 0033:0x7ffa3eb8f059 [ 244.228582] Code: 08 89 e8 5b 5d c3 66 2e 0f 1f 84 00 00 00 00 00 90 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 8f 1d 0d 00 f7 d8 64 89 01 48 [ 244.241307] RSP: 002b:00007ffa3e9c6eb8 EFLAGS: 00000206 ORIG_RAX: 000000000000012e [ 244.246474] RAX: ffffffffffffffda RBX: 00007ffa3e9c7cdc RCX: 00007ffa3eb8f059 [ 244.250478] RDX: 00007ffa3eb162b4 RSI: 0000000000000000 RDI: 00007ffa3e9c7fb0 [ 244.255396] RBP: 00007ffa3e9c6ed0 R08: 00007ffa3e9c76c0 R09: 0000000000000000 [ 244.260195] R10: 0000000000000000 R11: 0000000000000206 R12: ffffffffffffff80 [ 244.264201] R13: 000000000000001c R14: 00007ffc5d6b4260 R15: 00007ffa3e1c7000 [ 244.268303] </TASK>
Add a check_func_arg_reg_off() to the path in which the BPF verifier verifies the arguments of global function arguments, specifically those which take an argument of type ARG_PTR_TO_DYNPTR | MEM_RDONLY. Also, process_dynptr_func() doesn't appear to perform any explicit and strict type matching on the supplied register type, so let's also enforce that a register either type PTR_TO_STACK or CONST_PTR_TO_DYNPTR is by the caller.