CVE-2023-53057

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

Bluetooth: HCI: Fix global-out-of-bounds

To loop a variable-length array, hci_init_stage_sync(stage) considers that stage[i] is valid as long as stage[i-1].func is valid. Thus, the last element of stage[].func should be intentionally invalid as hci_init0[], le_init2[], and others did. However, amp_init1[] and amp_init2[] have no invalid element, letting hci_init_stage_sync() keep accessing amp_init1[] over its valid range. This patch fixes this by adding {} in the last of amp_init1[] and amp_init2[].

================================================================== BUG: KASAN: global-out-of-bounds in hci_dev_open_sync ( /v6.2-bzimage/net/bluetooth/hci_sync.c:3154 /v6.2-bzimage/net/bluetooth/hci_sync.c:3343 /v6.2-bzimage/net/bluetooth/hci_sync.c:4418 /v6.2-bzimage/net/bluetooth/hci_sync.c:4609 /v6.2-bzimage/net/bluetooth/hci_sync.c:4689) Read of size 8 at addr ffffffffaed1ab70 by task kworker/u5:0/1032 CPU: 0 PID: 1032 Comm: kworker/u5:0 Not tainted 6.2.0 #3 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04 Workqueue: hci1 hci_power_on Call Trace: dump_stack_lvl (/v6.2-bzimage/lib/dump_stack.c:107 (discriminator 1)) print_report (/v6.2-bzimage/mm/kasan/report.c:307 /v6.2-bzimage/mm/kasan/report.c:417) ? hci_dev_open_sync (/v6.2-bzimage/net/bluetooth/hci_sync.c:3154 /v6.2-bzimage/net/bluetooth/hci_sync.c:3343 /v6.2-bzimage/net/bluetooth/hci_sync.c:4418 /v6.2-bzimage/net/bluetooth/hci_sync.c:4609 /v6.2-bzimage/net/bluetooth/hci_sync.c:4689) kasan_report (/v6.2-bzimage/mm/kasan/report.c:184 /v6.2-bzimage/mm/kasan/report.c:519) ? hci_dev_open_sync (/v6.2-bzimage/net/bluetooth/hci_sync.c:3154 /v6.2-bzimage/net/bluetooth/hci_sync.c:3343 /v6.2-bzimage/net/bluetooth/hci_sync.c:4418 /v6.2-bzimage/net/bluetooth/hci_sync.c:4609 /v6.2-bzimage/net/bluetooth/hci_sync.c:4689) hci_dev_open_sync (/v6.2-bzimage/net/bluetooth/hci_sync.c:3154 /v6.2-bzimage/net/bluetooth/hci_sync.c:3343 /v6.2-bzimage/net/bluetooth/hci_sync.c:4418 /v6.2-bzimage/net/bluetooth/hci_sync.c:4609 /v6.2-bzimage/net/bluetooth/hci_sync.c:4689) ? __pfx_hci_dev_open_sync (/v6.2-bzimage/net/bluetooth/hci_sync.c:4635) ? mutex_lock (/v6.2-bzimage/./arch/x86/include/asm/atomic64_64.h:190 /v6.2-bzimage/./include/linux/atomic/atomic-long.h:443 /v6.2-bzimage/./include/linux/atomic/atomic-instrumented.h:1781 /v6.2-bzimage/kernel/locking/mutex.c:171 /v6.2-bzimage/kernel/locking/mutex.c:285) ? __pfx_mutex_lock (/v6.2-bzimage/kernel/locking/mutex.c:282) hci_power_on (/v6.2-bzimage/net/bluetooth/hci_core.c:485 /v6.2-bzimage/net/bluetooth/hci_core.c:984) ? __pfx_hci_power_on (/v6.2-bzimage/net/bluetooth/hci_core.c:969) ? read_word_at_a_time (/v6.2-bzimage/./include/asm-generic/rwonce.h:85) ? strscpy (/v6.2-bzimage/./arch/x86/include/asm/word-at-a-time.h:62 /v6.2-bzimage/lib/string.c:161) process_one_work (/v6.2-bzimage/kernel/workqueue.c:2294) worker_thread (/v6.2-bzimage/./include/linux/list.h:292 /v6.2-bzimage/kernel/workqueue.c:2437) ? __pfx_worker_thread (/v6.2-bzimage/kernel/workqueue.c:2379) kthread (/v6.2-bzimage/kernel/kthread.c:376) ? __pfx_kthread (/v6.2-bzimage/kernel/kthread.c:331) ret_from_fork (/v6.2-bzimage/arch/x86/entry/entry_64.S:314) The buggy address belongs to the variable: amp_init1+0x30/0x60 The buggy address belongs to the physical page: page:000000003a157ec6 refcount:1 mapcount:0 mapping:0000000000000000 ia flags: 0x200000000001000(reserved|node=0|zone=2) raw: 0200000000001000 ffffea0005054688 ffffea0005054688 000000000000000 raw: 0000000000000000 0000000000000000 00000001ffffffff 000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffffffffaed1aa00: f9 f9 f9 f9 00 00 00 00 f9 f9 f9 f9 00 00 00 00 ffffffffaed1aa80: 00 00 00 00 f9 f9 f9 f9 00 00 00 00 00 00 00 00

ffffffffaed1ab00: 00 f9 f9 f9 f9 f9 f9 f9 00 00 00 00 00 00 f9 f9

—truncated—

Weakness

The product reads data past the end, or before the beginning, of the intended buffer.

Affected Software

Potential Mitigations

• Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
• When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”
• Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
• To reduce the likelihood of introducing an out-of-bounds read, ensure that you validate and ensure correct calculations for any length argument, buffer size calculation, or offset. Be especially careful of relying on a sentinel (i.e. special character such as NUL) in untrusted inputs.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/540.html

References

• https://git.kernel.org/stable/c/8497222b22b591c6b2d106e0e3c1672ffe4e10e0
• https://git.kernel.org/stable/c/b3168abd24245aa0775c5a387dcf94d36ca7e738
• https://git.kernel.org/stable/c/bce56405201111807cc8e4f47c6de3e10b17c1ac