From: bot+bpf-ci@kernel.org
To: avinashpal441@gmail.com,bpf@vger.kernel.org
Cc: ast@kernel.org,daniel@iogearbox.net,andrii@kernel.org,netdev@vger.kernel.org,ast@kernel.org,andrii@kernel.org,daniel@iogearbox.net,martin.lau@kernel.org,eddyz87@gmail.com,yonghong.song@linux.dev,clm@meta.com,ihor.solodrai@linux.dev
Subject: Re: [PATCH] bpf: verifier: fix NULL deref in map_kptr_match_type() for scalar regs
Date: Sun, 19 Apr 2026 04:32:55 +0000 (UTC) [thread overview]
Message-ID: <557b90e63fb85b646de7ae4792eb2c06d6be251dcd95dabe9ed99435c82b85e0@mail.kernel.org> (raw)
In-Reply-To: <20260419040426.9672-1-avinashpal441@gmail.com>
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commit 6c1cde9635b1379ee40c94c5ecc8a7d09507c0c9
Author: Avinash Pal <avinashpal441@gmail.com>
bpf: verifier: fix NULL deref in map_kptr_match_type() for scalar regs
A NULL pointer dereference occurs in map_kptr_match_type() when a BPF
program attempts to store a scalar value (non-pointer register) into a
map slot annotated as a kptr (kernel pointer).
Link: https://bugzilla.kernel.org/show_bug.cgi?id=221372
This commit appears to fix a bug introduced in an earlier commit.
Should this include a Fixes: tag?
The fix guards against NULL reg->btf before calling btf_is_kernel(),
which suggests the vulnerability was introduced when map_kptr_match_type()
started using btf_is_kernel() without checking if reg->btf is NULL first.
Looking at the git history, commit 61df10c7799e ("bpf: Allow storing
unreferenced kptr in map") introduced map_kptr_match_type() and the call
to btf_is_kernel(reg->btf) without a NULL check.
Consider adding:
Fixes: 61df10c7799e ("bpf: Allow storing unreferenced kptr in map")
---
AI reviewed your patch. Please fix the bug or email reply why it's not a bug.
See: https://github.com/kernel-patches/vmtest/blob/master/ci/claude/README.md
CI run summary: https://github.com/kernel-patches/bpf/actions/runs/24620726038
next prev parent reply other threads:[~2026-04-19 4:32 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-19 4:04 [PATCH] bpf: verifier: fix NULL deref in map_kptr_match_type() for scalar regs Avinash Pal
2026-04-19 4:32 ` bot+bpf-ci [this message]
2026-04-19 5:01 ` sun jian
-- strict thread matches above, loose matches on Subject: below --
2026-04-19 3:59 Avinash Pal
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