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 565A525E834; Tue, 11 Mar 2025 15:21:08 +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=1741706468; cv=none; b=XpAeuL+L9vdHdEAE3bU754SqaQLnXDQpQkyJD9DSxtxXlHcRDsjWfbwnWBQpPVexAu2OeLj0ggnCDqnaAdT6m64FV4hJzakq2Rsf0eA970qzeTjbzaBSvg3kBlQa/tzN25dBi/yRchGLpF/BmYtxwftSzvuEleqUNwU2GcYmhN0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741706468; c=relaxed/simple; bh=ZW11oRBJnZ2dmGNKvmRrjUVXKfH8yk/0yIWm8ul3AHo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ZjqLtARtIy2IZDprFtDBi9auFijBarAfcxZiG7DknsqWlAE07Qt3vOdpkNRpnUotUNKIC9vfNg4zh7vo/WZoxqM4Q+qYpHJ3yhBaBgn7LXu7kwBYV9f5EyO0UGhKk+2OxBfrEQZmQ+5RyLTkI/+femhM7W4fDns6P8QjlvdP+7c= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=iLyD3jKR; 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="iLyD3jKR" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D25A9C4CEE9; Tue, 11 Mar 2025 15:21:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741706468; bh=ZW11oRBJnZ2dmGNKvmRrjUVXKfH8yk/0yIWm8ul3AHo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iLyD3jKRcUbbOBqv/n2C0WiNClOKhCmqmhiN1KD5/5MBP1SBy2KHENtZjwqkTta5k 9W3gwujNQUTODqbj6xA1pZAHi3jBqS+hQybYAixGDBsFX3M6XSTH7zOqbRHkgHGkym nseYkIMdt9r9vkYgIhAqObp5Te50o5EjUsceUAns= 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 5.10 059/462] bpf: Send signals asynchronously if !preemptible Date: Tue, 11 Mar 2025 15:55:25 +0100 Message-ID: <20250311145800.684693627@linuxfoundation.org> X-Mailer: git-send-email 2.48.1 In-Reply-To: <20250311145758.343076290@linuxfoundation.org> References: <20250311145758.343076290@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 5.10-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 71e0c1bc9759e..1656a7d9bb697 100644 --- a/kernel/trace/bpf_trace.c +++ b/kernel/trace/bpf_trace.c @@ -1081,7 +1081,7 @@ 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