CVE-2022-50129

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

RDMA/srpt: Fix a use-after-free

Change the LIO port members inside struct srpt_port from regular members into pointers. Allocate the LIO port data structures from inside srpt_make_tport() and free these from inside srpt_make_tport(). Keep struct srpt_device as long as either an RDMA port or a LIO target port is associated with it. This patch decouples the lifetime of struct srpt_port (controlled by the RDMA core) and struct srpt_port_id (controlled by LIO). This patch fixes the following KASAN complaint:

BUG: KASAN: use-after-free in srpt_enable_tpg+0x31/0x70 [ib_srpt] Read of size 8 at addr ffff888141cc34b8 by task check/5093

Call Trace: show_stack+0x4e/0x53 dump_stack_lvl+0x51/0x66 print_address_description.constprop.0.cold+0xea/0x41e print_report.cold+0x90/0x205 kasan_report+0xb9/0xf0 __asan_load8+0x69/0x90 srpt_enable_tpg+0x31/0x70 [ib_srpt] target_fabric_tpg_base_enable_store+0xe2/0x140 [target_core_mod] configfs_write_iter+0x18b/0x210 new_sync_write+0x1f2/0x2f0 vfs_write+0x3e3/0x540 ksys_write+0xbb/0x140 __x64_sys_write+0x42/0x50 do_syscall_64+0x34/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0

Weakness

The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory “belongs” to the code that operates on the new pointer.

Affected Software

Potential Mitigations

References

• https://git.kernel.org/stable/c/388326bb1c32fcd09371c1d494af71471ef3a04b
• https://git.kernel.org/stable/c/4ee8c39968a648d58b273582d4b021044a41ee5e
• https://git.kernel.org/stable/c/b5605148e6ce36bb21020d49010b617693933128
• https://git.kernel.org/stable/c/de95b52d9aabc979166aba81ccbe623aaf9c16a1
• https://git.kernel.org/stable/c/e60d7e2462bf57273563c4e00dbfa79ee973b9e2