From 4d8f6679b03ab39734af0cabc883cde5c9c95ff4 Mon Sep 17 00:00:00 2001 From: Rik van Riel Date: Tue, 8 Oct 2024 17:07:35 -0400 Subject: [PATCH] bpf: use kvzmalloc to allocate BPF verifier environment [ Upstream commit 434247637c66e1be2bc71a9987d4c3f0d8672387 ] The kzmalloc call in bpf_check can fail when memory is very fragmented, which in turn can lead to an OOM kill. Use kvzmalloc to fall back to vmalloc when memory is too fragmented to allocate an order 3 sized bpf verifier environment. Admittedly this is not a very common case, and only happens on systems where memory has already been squeezed close to the limit, but this does not seem like much of a hot path, and it's a simple enough fix. Signed-off-by: Rik van Riel Reviewed-by: Shakeel Butt Link: https://lore.kernel.org/r/20241008170735.16766766@imladris.surriel.com Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin --- kernel/bpf/verifier.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 60db311480d0..931611d22736 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -12564,7 +12564,7 @@ int bpf_check(struct bpf_prog **prog, union bpf_attr *attr, /* 'struct bpf_verifier_env' can be global, but since it's not small, * allocate/free it every time bpf_check() is called */ - env = kzalloc(sizeof(struct bpf_verifier_env), GFP_KERNEL); + env = kvzalloc(sizeof(struct bpf_verifier_env), GFP_KERNEL); if (!env) return -ENOMEM; log = &env->log; @@ -12755,6 +12755,6 @@ err_unlock: mutex_unlock(&bpf_verifier_lock); vfree(env->insn_aux_data); err_free_env: - kfree(env); + kvfree(env); return ret; }