linux/security
Andrii Nakryiko 1b67772e4e bpf,lsm: Refactor bpf_prog_alloc/bpf_prog_free LSM hooks
Based on upstream discussion ([0]), rework existing
bpf_prog_alloc_security LSM hook. Rename it to bpf_prog_load and instead
of passing bpf_prog_aux, pass proper bpf_prog pointer for a full BPF
program struct. Also, we pass bpf_attr union with all the user-provided
arguments for BPF_PROG_LOAD command.  This will give LSMs as much
information as we can basically provide.

The hook is also BPF token-aware now, and optional bpf_token struct is
passed as a third argument. bpf_prog_load LSM hook is called after
a bunch of sanity checks were performed, bpf_prog and bpf_prog_aux were
allocated and filled out, but right before performing full-fledged BPF
verification step.

bpf_prog_free LSM hook is now accepting struct bpf_prog argument, for
consistency. SELinux code is adjusted to all new names, types, and
signatures.

Note, given that bpf_prog_load (previously bpf_prog_alloc) hook can be
used by some LSMs to allocate extra security blob, but also by other
LSMs to reject BPF program loading, we need to make sure that
bpf_prog_free LSM hook is called after bpf_prog_load/bpf_prog_alloc one
*even* if the hook itself returned error. If we don't do that, we run
the risk of leaking memory. This seems to be possible today when
combining SELinux and BPF LSM, as one example, depending on their
relative ordering.

Also, for BPF LSM setup, add bpf_prog_load and bpf_prog_free to
sleepable LSM hooks list, as they are both executed in sleepable
context. Also drop bpf_prog_load hook from untrusted, as there is no
issue with refcount or anything else anymore, that originally forced us
to add it to untrusted list in c0c852dd18 ("bpf: Do not mark certain LSM
hook arguments as trusted"). We now trigger this hook much later and it
should not be an issue anymore.

  [0] https://lore.kernel.org/bpf/9fe88aef7deabbe87d3fc38c4aea3c69.paul@paul-moore.com/

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Paul Moore <paul@paul-moore.com>
Link: https://lore.kernel.org/bpf/20240124022127.2379740-10-andrii@kernel.org
2024-01-24 16:21:01 -08:00
..
apparmor misc cleanups (the part that hadn't been picked by individual fs trees) 2024-01-11 20:23:50 -08:00
bpf lsm: mark the lsm_id variables are marked as static 2023-11-12 22:54:42 -05:00
integrity integrity-v6.8 2024-01-09 13:24:06 -08:00
keys integrity-v6.8 2024-01-09 13:24:06 -08:00
landlock Landlock updates for v6.8-rc1 2024-01-09 13:22:15 -08:00
loadpin lsm: mark the lsm_id variables are marked as static 2023-11-12 22:54:42 -05:00
lockdown LSM: Identify modules by more than name 2023-11-12 22:54:42 -05:00
safesetid lsm: mark the lsm_id variables are marked as static 2023-11-12 22:54:42 -05:00
selinux bpf,lsm: Refactor bpf_prog_alloc/bpf_prog_free LSM hooks 2024-01-24 16:21:01 -08:00
smack for-6.8/io_uring-2024-01-08 2024-01-11 14:19:23 -08:00
tomoyo lsm: new security_file_ioctl_compat() hook 2023-12-24 15:48:03 -05:00
yama lsm: mark the lsm_id variables are marked as static 2023-11-12 22:54:42 -05:00
commoncap.c lsm: mark the lsm_id variables are marked as static 2023-11-12 22:54:42 -05:00
device_cgroup.c device_cgroup: Fix kernel-doc warnings in device_cgroup 2023-06-21 09:30:49 -04:00
inode.c security: convert to new timestamp accessors 2023-10-18 14:08:31 +02:00
Kconfig mm/slab: remove HAVE_HARDENED_USERCOPY_ALLOCATOR 2023-05-24 15:38:17 +02:00
Kconfig.hardening hardening: Move BUG_ON_DATA_CORRUPTION to hardening options 2023-08-15 14:57:25 -07:00
lsm_audit.c lsm: fix a number of misspellings 2023-05-25 17:52:15 -04:00
lsm_syscalls.c LSM: Helpers for attribute names and filling lsm_ctx 2023-11-12 22:54:42 -05:00
Makefile LSM: syscalls for current process attributes 2023-11-12 22:54:42 -05:00
min_addr.c sysctl: pass kernel pointers to ->proc_handler 2020-04-27 02:07:40 -04:00
security.c bpf,lsm: Refactor bpf_prog_alloc/bpf_prog_free LSM hooks 2024-01-24 16:21:01 -08:00