From patchwork Wed Apr 3 16:55:23 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anthony Iliopoulos X-Patchwork-Id: 87989 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 6D1F53858401 for ; Wed, 3 Apr 2024 16:55:51 +0000 (GMT) X-Original-To: libc-alpha@sourceware.org Delivered-To: libc-alpha@sourceware.org Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) by sourceware.org (Postfix) with ESMTPS id C90E03858401 for ; Wed, 3 Apr 2024 16:55:28 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org C90E03858401 Authentication-Results: sourceware.org; dmarc=pass (p=quarantine dis=none) header.from=suse.com Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=suse.com ARC-Filter: OpenARC Filter v1.0.0 sourceware.org C90E03858401 Authentication-Results: server2.sourceware.org; arc=none smtp.remote-ip=195.135.223.130 ARC-Seal: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1712163330; cv=none; b=dDKI9kuBpduZCb/OcZt12DTyttMNbLge+3221O5wUmDzgAce9m9E2cOA+RFN6RfiRB1m1+DCqYgfn3yF/LE3Kf5Pbd5dKUgaS5HEJP+Abr3Uyq1baf136P5ysAxYTQK+qRfUZJJl/DYHHVXrmt09AjZPQ2vZDlghX/nbqK5yUuI= ARC-Message-Signature: i=1; a=rsa-sha256; d=sourceware.org; s=key; t=1712163330; c=relaxed/simple; bh=Q8Be2UPWHbirTODdz+/sBG5FaKYUpTQHebr6IpMzw8c=; h=DKIM-Signature:From:To:Subject:Date:Message-ID:MIME-Version; b=m4SUo1lMzs0bw3OkyU70xn0KBR7F1cbbq+PwZVN76ijCxt00hm47cqdlyCWtDq8raCE7jKscHzwH3AzVUWrVwvJmFo7Zb/Cf5FwGZdNdPbSN12dPXlUmoOsLlDCYxxQesdgZEIXmEhyfr/kx223uQrni55P+AWCzHKMhF2Swnxg= ARC-Authentication-Results: i=1; server2.sourceware.org Received: from kunlun.arch.suse.cz (unknown [10.100.128.76]) by smtp-out1.suse.de (Postfix) with ESMTP id BD8D721E1C for ; Wed, 3 Apr 2024 16:55:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1712163326; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=k3UU5vCDpY3BH2fnfpyvFm6iJjxERnGIBsBBv2LXfo4=; b=cTsbBJiLl7ENBRpPeg02iAEuiwv7pLaK1DxDg5wuzXIeLtWcclX5Dt/mU2x/xgSkfoLxF0 DLOjRcP3FdFNL/jKBVCZGn0Qo+b+/E1xLzoKdSY7atpkr4gZNDP9ELHp5QUUQ0ZVJ9Up5M LehMx0F7QJQPuK0KcSnKwMSjOTUCnng= Authentication-Results: smtp-out1.suse.de; none From: Anthony Iliopoulos To: libc-alpha@sourceware.org Subject: [PATCH] arc4random: fix getrandom fallback to /dev/urandom Date: Wed, 3 Apr 2024 18:55:23 +0200 Message-ID: <20240403165523.23129-1-ailiop@suse.com> X-Mailer: git-send-email 2.44.0 MIME-Version: 1.0 X-Spamd-Result: default: False [1.20 / 50.00]; MID_CONTAINS_FROM(1.00)[]; R_MISSING_CHARSET(0.50)[]; NEURAL_HAM_SHORT(-0.20)[-0.998]; MIME_GOOD(-0.10)[text/plain]; BAYES_HAM(-0.00)[38.98%]; RCVD_COUNT_ZERO(0.00)[0]; ARC_NA(0.00)[]; RCPT_COUNT_ONE(0.00)[1]; DKIM_SIGNED(0.00)[suse.com:s=susede1]; FUZZY_BLOCKED(0.00)[rspamd.com]; TO_MATCH_ENVRCPT_ALL(0.00)[]; FROM_HAS_DN(0.00)[]; MIME_TRACE(0.00)[0:+]; FROM_EQ_ENVFROM(0.00)[]; TO_DN_NONE(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.com:email,kunlun.arch.suse.cz:helo] X-Spam-Score: 1.20 X-Spam-Status: No, score=-12.3 required=5.0 tests=BAYES_00, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, GIT_PATCH_0, SPF_HELO_NONE, SPF_NONE, TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org X-BeenThere: libc-alpha@sourceware.org X-Mailman-Version: 2.1.30 Precedence: list List-Id: Libc-alpha mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: libc-alpha-bounces+patchwork=sourceware.org@sourceware.org arc4random_buf relies on the errno of getrandom_nocancel to fallback to /dev/urandom, but getrandom_nocancel returns a status code instead of the syscall errno (-ENOSYS) so it breaks the expectation and thus the fallback in cases where a kernel does not support the getrandom syscall. Commit 609c9d0951da ("malloc: Do not clobber errno on __getrandom_nocancel (BZ #29624)") changed __getrandom_nocancel from INLINE_SYSCALL_CALL to INTERNAL_SYSCALL_CALL and modified arc4random_buf to rely on the return status instead of errno. Commit 5a85786a9005 ("Make __getrandom_nocancel set errno and add a _nostatus version") changed __getrandom_nocancel back to INLINE_SYSCALL_CALL and added a __getrandom_nocancel_nostatus variant that calls via INTERNAL_SYSCALL_CALL, but this broke the fallback of arc4random on kernels where the getrandom syscall is not available. Fix it by calling __getrandom_nocancel_nostatus from arc4random_buf so that the fallback works again. Signed-off-by: Anthony Iliopoulos Fixes: 5a85786a9005 ("Make __getrandom_nocancel set errno and add a _nostatus version") --- stdlib/arc4random.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/stdlib/arc4random.c b/stdlib/arc4random.c index 3ae8fc130234..9b6a6ee85150 100644 --- a/stdlib/arc4random.c +++ b/stdlib/arc4random.c @@ -42,7 +42,7 @@ __arc4random_buf (void *p, size_t n) for (;;) { - l = TEMP_FAILURE_RETRY (__getrandom_nocancel (p, n, 0)); + l = TEMP_FAILURE_RETRY (__getrandom_nocancel_nostatus (p, n, 0)); if (l > 0) { if ((size_t) l == n)