CVE-2023-53090

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

drm/amdkfd: Fix an illegal memory access

In the kfd_wait_on_events() function, the kfd_event_waiter structure is allocated by alloc_event_waiters(), but the event field of the waiter structure is not initialized; When copy_from_user() fails in the kfd_wait_on_events() function, it will enter exception handling to release the previously allocated memory of the waiter structure; Due to the event field of the waiters structure being accessed in the free_waiters() function, this results in illegal memory access and system crash, here is the crash log:

localhost kernel: RIP: 0010:native_queued_spin_lock_slowpath+0x185/0x1e0 localhost kernel: RSP: 0018:ffffaa53c362bd60 EFLAGS: 00010082 localhost kernel: RAX: ff3d3d6bff4007cb RBX: 0000000000000282 RCX: 00000000002c0000 localhost kernel: RDX: ffff9e855eeacb80 RSI: 000000000000279c RDI: ffffe7088f6a21d0 localhost kernel: RBP: ffffe7088f6a21d0 R08: 00000000002c0000 R09: ffffaa53c362be64 localhost kernel: R10: ffffaa53c362bbd8 R11: 0000000000000001 R12: 0000000000000002 localhost kernel: R13: ffff9e7ead15d600 R14: 0000000000000000 R15: ffff9e7ead15d698 localhost kernel: FS: 0000152a3d111700(0000) GS:ffff9e855ee80000(0000) knlGS:0000000000000000 localhost kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 localhost kernel: CR2: 0000152938000010 CR3: 000000044d7a4000 CR4: 00000000003506e0 localhost kernel: Call Trace: localhost kernel: _raw_spin_lock_irqsave+0x30/0x40 localhost kernel: remove_wait_queue+0x12/0x50 localhost kernel: kfd_wait_on_events+0x1b6/0x490 [hydcu] localhost kernel: ? ftrace_graph_caller+0xa0/0xa0 localhost kernel: kfd_ioctl+0x38c/0x4a0 [hydcu] localhost kernel: ? kfd_ioctl_set_trap_handler+0x70/0x70 [hydcu] localhost kernel: ? kfd_ioctl_create_queue+0x5a0/0x5a0 [hydcu] localhost kernel: ? ftrace_graph_caller+0xa0/0xa0 localhost kernel: __x64_sys_ioctl+0x8e/0xd0 localhost kernel: ? syscall_trace_enter.isra.18+0x143/0x1b0 localhost kernel: do_syscall_64+0x33/0x80 localhost kernel: entry_SYSCALL_64_after_hwframe+0x44/0xa9 localhost kernel: RIP: 0033:0x152a4dff68d7

Allocate the structure with kcalloc, and remove redundant 0-initialization and a redundant loop condition check.

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/2fece63b55c5d74cd6f5de51159e2cde37e10555
• https://git.kernel.org/stable/c/4fc8fff378b2f2039f2a666d9f8c570f4e58352c
• https://git.kernel.org/stable/c/5a3fb3b745af0ce46ec2e0c8e507bae45b937334
• https://git.kernel.org/stable/c/61f306f8df0d5559659c5578cf6d95236bcdcb25
• https://git.kernel.org/stable/c/6936525142a015e854d0a23e9ad9ea0a28b3843d
• https://git.kernel.org/stable/c/bbf5eada4334a96e3a204b2307ff5b14dc380b0b
• https://git.kernel.org/stable/c/d9923e7214a870b312bf61f6a89c7554d0966985