title: bpf: Fix re-attachment branch in bpf_tracing_prog_attach
description: In the Linux kernel, the following vulnerability has been resolved:
bpf: Fix re-attachment branch in bpf_tracing_prog_attach
The following case can cause a crash due to missing attach_btf:
1) load rawtp program
2) load fentry program with rawtp as target_fd
3) create tracing link for fentry program with target_fd = 0
4) repeat 3
In the end we have:
- prog->aux->dst_trampoline == NULL
- tgt_prog == NULL (because we did not provide target_fd to link_create)
- prog->aux->attach_btf == NULL (the program was loaded with attach_prog_fd=X)
- the program was loaded for tgt_prog but we have no way to find out which one
BUG: kernel NULL pointer dereference, address: 0000000000000058
Call Trace:
<TASK>
? __die+0x20/0x70
? page_fault_oops+0x15b/0x430
? fixup_exception+0x22/0x330
? exc_page_fault+0x6f/0x170
? asm_exc_page_fault+0x22/0x30
? bpf_tracing_prog_attach+0x279/0x560
? btf_obj_id+0x5/0x10
bpf_tracing_prog_attach+0x439/0x560
__sys_bpf+0x1cf4/0x2de0
__x64_sys_bpf+0x1c/0x30
do_syscall_64+0x41/0xf0
entry_SYSCALL_64_after_hwframe+0x6e/0x76
Return -EINVAL in this situation.
affected:
{
product: Linux
vendor: Linux
defaultStatus: unaffected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: f3a95075549e, lessThan: a7b98aa10f89, status: affected, versionType: git
version: f3a95075549e, lessThan: 6cc9c0af0aa0, status: affected, versionType: git
version: f3a95075549e, lessThan: 8c8bcd45e9b1, status: affected, versionType: git
version: f3a95075549e, lessThan: 50ae82f080cf, status: affected, versionType: git
version: f3a95075549e, lessThan: 715d82ba636c, status: affected, versionType: git
}
{
product: Linux
vendor: Linux
defaultStatus: affected
repo: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
versions:
version: 5.13, status: affected
version: 0, lessThan: 5.13, status: unaffected, versionType: custom
version: 5.15.148, lessThanOrEqual: 5.15.*, status: unaffected, versionType: custom
version: 6.1.75, lessThanOrEqual: 6.1.*, status: unaffected, versionType: custom
version: 6.6.14, lessThanOrEqual: 6.6.*, status: unaffected, versionType: custom
version: 6.7.2, lessThanOrEqual: 6.7.*, status: unaffected, versionType: custom
version: 6.8, lessThanOrEqual: *, status: unaffected, versionType: original_commit_for_fix
}
