From 9b459804ff9973e173fabafba2a1319f771e85fa Mon Sep 17 00:00:00 2001 From: Lorenz Bauer Date: Mon, 6 Mar 2023 11:21:37 +0000 Subject: btf: fix resolving BTF_KIND_VAR after ARRAY, STRUCT, UNION, PTR btf_datasec_resolve contains a bug that causes the following BTF to fail loading: [1] DATASEC a size=2 vlen=2 type_id=4 offset=0 size=1 type_id=7 offset=1 size=1 [2] INT (anon) size=1 bits_offset=0 nr_bits=8 encoding=(none) [3] PTR (anon) type_id=2 [4] VAR a type_id=3 linkage=0 [5] INT (anon) size=1 bits_offset=0 nr_bits=8 encoding=(none) [6] TYPEDEF td type_id=5 [7] VAR b type_id=6 linkage=0 This error message is printed during btf_check_all_types: [1] DATASEC a size=2 vlen=2 type_id=7 offset=1 size=1 Invalid type By tracing btf_*_resolve we can pinpoint the problem: btf_datasec_resolve(depth: 1, type_id: 1, mode: RESOLVE_TBD) = 0 btf_var_resolve(depth: 2, type_id: 4, mode: RESOLVE_TBD) = 0 btf_ptr_resolve(depth: 3, type_id: 3, mode: RESOLVE_PTR) = 0 btf_var_resolve(depth: 2, type_id: 4, mode: RESOLVE_PTR) = 0 btf_datasec_resolve(depth: 1, type_id: 1, mode: RESOLVE_PTR) = -22 The last invocation of btf_datasec_resolve should invoke btf_var_resolve by means of env_stack_push, instead it returns EINVAL. The reason is that env_stack_push is never executed for the second VAR. if (!env_type_is_resolve_sink(env, var_type) && !env_type_is_resolved(env, var_type_id)) { env_stack_set_next_member(env, i + 1); return env_stack_push(env, var_type, var_type_id); } env_type_is_resolve_sink() changes its behaviour based on resolve_mode. For RESOLVE_PTR, we can simplify the if condition to the following: (btf_type_is_modifier() || btf_type_is_ptr) && !env_type_is_resolved() Since we're dealing with a VAR the clause evaluates to false. This is not sufficient to trigger the bug however. The log output and EINVAL are only generated if btf_type_id_size() fails. if (!btf_type_id_size(btf, &type_id, &type_size)) { btf_verifier_log_vsi(env, v->t, vsi, "Invalid type"); return -EINVAL; } Most types are sized, so for example a VAR referring to an INT is not a problem. The bug is only triggered if a VAR points at a modifier. Since we skipped btf_var_resolve that modifier was also never resolved, which means that btf_resolved_type_id returns 0 aka VOID for the modifier. This in turn causes btf_type_id_size to return NULL, triggering EINVAL. To summarise, the following conditions are necessary: - VAR pointing at PTR, STRUCT, UNION or ARRAY - Followed by a VAR pointing at TYPEDEF, VOLATILE, CONST, RESTRICT or TYPE_TAG The fix is to reset resolve_mode to RESOLVE_TBD before attempting to resolve a VAR from a DATASEC. Fixes: 1dc92851849c ("bpf: kernel side support for BTF Var and DataSec") Signed-off-by: Lorenz Bauer Link: https://lore.kernel.org/r/20230306112138.155352-2-lmb@isovalent.com Signed-off-by: Martin KaFai Lau --- kernel/bpf/btf.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/bpf/btf.c b/kernel/bpf/btf.c index fa22ec79ac0e..73780748404c 100644 --- a/kernel/bpf/btf.c +++ b/kernel/bpf/btf.c @@ -4569,6 +4569,7 @@ static int btf_datasec_resolve(struct btf_verifier_env *env, struct btf *btf = env->btf; u16 i; + env->resolve_mode = RESOLVE_TBD; for_each_vsi_from(i, v->next_member, v->t, vsi) { u32 var_type_id = vsi->type, type_id, type_size = 0; const struct btf_type *var_type = btf_type_by_id(env->btf, -- cgit v1.2.3 From 03e1d60e177eedbd302b77af4ea5e21b5a7ade31 Mon Sep 17 00:00:00 2001 From: David Disseldorp Date: Tue, 7 Mar 2023 16:21:06 +0100 Subject: watch_queue: fix IOC_WATCH_QUEUE_SET_SIZE alloc error paths The watch_queue_set_size() allocation error paths return the ret value set via the prior pipe_resize_ring() call, which will always be zero. As a result, IOC_WATCH_QUEUE_SET_SIZE callers such as "keyctl watch" fail to detect kernel wqueue->notes allocation failures and proceed to KEYCTL_WATCH_KEY, with any notifications subsequently lost. Fixes: c73be61cede58 ("pipe: Add general notification queue support") Signed-off-by: David Disseldorp Signed-off-by: Christian Brauner (Microsoft) --- kernel/watch_queue.c | 1 + 1 file changed, 1 insertion(+) (limited to 'kernel') diff --git a/kernel/watch_queue.c b/kernel/watch_queue.c index a6f9bdd956c3..f10f403104e7 100644 --- a/kernel/watch_queue.c +++ b/kernel/watch_queue.c @@ -273,6 +273,7 @@ long watch_queue_set_size(struct pipe_inode_info *pipe, unsigned int nr_notes) if (ret < 0) goto error; + ret = -ENOMEM; pages = kcalloc(sizeof(struct page *), nr_pages, GFP_KERNEL); if (!pages) goto error; -- cgit v1.2.3 From a402f1e35313fc7ce2ca60f543c4402c2c7c3544 Mon Sep 17 00:00:00 2001 From: Tobias Klauser Date: Wed, 8 Mar 2023 11:51:26 +0100 Subject: fork: allow CLONE_NEWTIME in clone3 flags Currently, calling clone3() with CLONE_NEWTIME in clone_args->flags fails with -EINVAL. This is because CLONE_NEWTIME intersects with CSIGNAL. However, CSIGNAL was deprecated when clone3 was introduced in commit 7f192e3cd316 ("fork: add clone3"), allowing re-use of that part of clone flags. Fix this by explicitly allowing CLONE_NEWTIME in clone3_args_valid. This is also in line with the respective check in check_unshare_flags which allow CLONE_NEWTIME for unshare(). Fixes: 769071ac9f20 ("ns: Introduce Time Namespace") Cc: Andrey Vagin Cc: Christian Brauner Cc: stable@vger.kernel.org Signed-off-by: Tobias Klauser Reviewed-by: Christian Brauner Signed-off-by: Christian Brauner (Microsoft) --- kernel/fork.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'kernel') diff --git a/kernel/fork.c b/kernel/fork.c index f68954d05e89..d8cda4c6de6c 100644 --- a/kernel/fork.c +++ b/kernel/fork.c @@ -2936,7 +2936,7 @@ static bool clone3_args_valid(struct kernel_clone_args *kargs) * - make the CLONE_DETACHED bit reusable for clone3 * - make the CSIGNAL bits reusable for clone3 */ - if (kargs->flags & (CLONE_DETACHED | CSIGNAL)) + if (kargs->flags & (CLONE_DETACHED | (CSIGNAL & (~CLONE_NEWTIME)))) return false; if ((kargs->flags & (CLONE_SIGHAND | CLONE_CLEAR_SIGHAND)) == -- cgit v1.2.3