From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B25AC151988; Wed, 5 Feb 2025 14:34:39 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738766079; cv=none; b=C/Ymo/Av/95Y9o44tTNdmnRfbI/v0iBNg/XYc4wtD8cPXRzbgMjUxIG904+j3pHL+4o0Rom1/CJNto4uhZjJp24foAJkk6YM2/SN+orV16gHDmwM9l/JrjYUf63YKKlSWAW6roMwujhBkp6mM9iREjfeXc1wpp0z7mUNRSoMdIs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1738766079; c=relaxed/simple; bh=ebDP24mmcd8QOvjZR4uIF+ge30bKEc21R8jhZttCSsY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=NnilFXopQE63ibI9E8dIk5rbi270ueCK6g3utSttGKWck8yUcUqb+VyV1fYi4dQurlt0Y3BPXeKaDUyve/x4oqSCvHWChhPusQJRpZXZbX/Pyp7o3eAqJPY50UBljlP6EyQ+ekqy93w4mpbMNbnp+CRh6ByeBNP31xau+wKjHlE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=dM73epCQ; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="dM73epCQ" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 16746C4CED1; Wed, 5 Feb 2025 14:34:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1738766079; bh=ebDP24mmcd8QOvjZR4uIF+ge30bKEc21R8jhZttCSsY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dM73epCQknDIW06zwuWyCgJQvTCsV3cntozz12NbvQxT2HZyhviMqSjwgdVFKWxIN U8SEj39Z9I4IyhhGXI9hB6Dy12ghzfb4c4kaBfb5ksyIZs5E27154EH925rPY2IxZd K2pBWk4q2V/ava78tnM3O5bTqxYwofzXPh3cHcik= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+97da3d7e0112d59971de@syzkaller.appspotmail.com, Puranjay Mohan , Yonghong Song , Alexei Starovoitov , Sasha Levin Subject: [PATCH 6.12 285/590] bpf: Send signals asynchronously if !preemptible Date: Wed, 5 Feb 2025 14:40:40 +0100 Message-ID: <20250205134506.181746452@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250205134455.220373560@linuxfoundation.org> References: <20250205134455.220373560@linuxfoundation.org> User-Agent: quilt/0.68 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Puranjay Mohan [ Upstream commit 87c544108b612512b254c8f79aa5c0a8546e2cc4 ] BPF programs can execute in all kinds of contexts and when a program running in a non-preemptible context uses the bpf_send_signal() kfunc, it will cause issues because this kfunc can sleep. Change `irqs_disabled()` to `!preemptible()`. Reported-by: syzbot+97da3d7e0112d59971de@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/67486b09.050a0220.253251.0084.GAE@google.com/ Fixes: 1bc7896e9ef4 ("bpf: Fix deadlock with rq_lock in bpf_send_signal()") Signed-off-by: Puranjay Mohan Acked-by: Yonghong Song Link: https://lore.kernel.org/r/20250115103647.38487-1-puranjay@kernel.org Signed-off-by: Alexei Starovoitov Signed-off-by: Sasha Levin --- kernel/trace/bpf_trace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/bpf_trace.c b/kernel/trace/bpf_trace.c index b5cf605fb0e60..449efaaa387a6 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -833,7 +833,7 @@ static int bpf_send_signal_common(u32 sig, enum pid_type type) if (unlikely(is_global_init(current))) return -EPERM; - if (irqs_disabled()) { + if (!preemptible()) { /* Do an early check on signal validity. Otherwise, * the error is lost in deferred irq_work. */ -- 2.39.5