CVE-2024-26591

In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> bpf: Fix re-attachment branch in bpf_tracing_prog_attach<br /> <br /> The following case can cause a crash due to missing attach_btf:<br /> <br /> 1) load rawtp program<br /> 2) load fentry program with rawtp as target_fd<br /> 3) create tracing link for fentry program with target_fd = 0<br /> 4) repeat 3<br /> <br /> In the end we have:<br /> <br /> - prog-&gt;aux-&gt;dst_trampoline == NULL<br /> - tgt_prog == NULL (because we did not provide target_fd to link_create)<br /> - prog-&gt;aux-&gt;attach_btf == NULL (the program was loaded with attach_prog_fd=X)<br /> - the program was loaded for tgt_prog but we have no way to find out which one<br /> <br /> BUG: kernel NULL pointer dereference, address: 0000000000000058<br /> Call Trace:<br /> <br /> ? __die+0x20/0x70<br /> ? page_fault_oops+0x15b/0x430<br /> ? fixup_exception+0x22/0x330<br /> ? exc_page_fault+0x6f/0x170<br /> ? asm_exc_page_fault+0x22/0x30<br /> ? bpf_tracing_prog_attach+0x279/0x560<br /> ? btf_obj_id+0x5/0x10<br /> bpf_tracing_prog_attach+0x439/0x560<br /> __sys_bpf+0x1cf4/0x2de0<br /> __x64_sys_bpf+0x1c/0x30<br /> do_syscall_64+0x41/0xf0<br /> entry_SYSCALL_64_after_hwframe+0x6e/0x76<br /> <br /> Return -EINVAL in this situation.