From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp-out1.suse.de (smtp-out1.suse.de [195.135.223.130]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CFD74F9E8 for ; Mon, 27 Jul 2026 00:12:19 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=195.135.223.130 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785111141; cv=none; b=kGEyMDzpRv88GTm+bLSE0bLgv2b8i8bDGiZcfHwXTuMO20PPWVkHV8XE54JClb28e7CT7dZ/uLmvQf4tXhR0fAvzcfP6mUuNCjrpjOxKXcTzUJDkpX9NblJ691/X5EG2i4U+SA2dkdrjArppyJJKerlCbiXKGssNLRYFOnJTh2o= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1785111141; c=relaxed/simple; bh=eWasTVal4kY8/UqRXzT0g5VNE+QEIsTmERV/2l89Qwk=; h=From:To:Cc:Subject:In-Reply-To:References:Date:Message-ID: MIME-Version:Content-Type; b=ZYbUO/rKL8zHxHQiw3y8/MQtdbw6YFNHrGDmhiicpBlg3gHYkc0rdjGlOBbcTnp8CBGM4Cm2Hq8kBcPDm44KQY4mBjhO9I15/Wnf7geTqpdo9+sGqfiV8FBaT9ljjlbHuUriYV0dYL3m8n/bes8C61zMe0mqd91vdJnh+UH8RS0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de; spf=pass smtp.mailfrom=suse.de; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=M9O/oOh8; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=Vwer7Yyh; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b=CUn7fKFs; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b=6TQh8GYF; arc=none smtp.client-ip=195.135.223.130 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=suse.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=suse.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="M9O/oOh8"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="Vwer7Yyh"; dkim=pass (1024-bit key) header.d=suse.de header.i=@suse.de header.b="CUn7fKFs"; dkim=permerror (0-bit key) header.d=suse.de header.i=@suse.de header.b="6TQh8GYF" Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 6E27D7D867; Mon, 27 Jul 2026 00:12:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1785111133; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=eWasTVal4kY8/UqRXzT0g5VNE+QEIsTmERV/2l89Qwk=; b=M9O/oOh8fzNux1yeEsURSL0nNWFkgyQZlg0WXWHQB9zEInrBTUKxZ8xFAZyyWgWYX90SHI RB2vlu8BkUNQ7IuKSqaVOyAfquAdU5EjOrVGUtHxcJGTKZhgFf7sBHXqjw7KJusQKYARbn 18FQb1noU2v1tmj1/umZSyIXSVUMIRw= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1785111133; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=eWasTVal4kY8/UqRXzT0g5VNE+QEIsTmERV/2l89Qwk=; b=Vwer7YyhbCngqqjkLGSfORkHTQAFzjGhCzXQ52zXBztz+CpfLQP1UK8iswB3hGP/L3+F2P MNsSceFG13nL9EDQ== Authentication-Results: smtp-out1.suse.de; dkim=pass header.d=suse.de header.s=susede2_rsa header.b=CUn7fKFs; dkim=pass header.d=suse.de header.s=susede2_ed25519 header.b=6TQh8GYF DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_rsa; t=1785111129; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=eWasTVal4kY8/UqRXzT0g5VNE+QEIsTmERV/2l89Qwk=; b=CUn7fKFsz3PPZytXv+pjS9RpUrQnZs1zjWs8xIyMS6xfrXCuggomQB4O+L49gIaRA6UC7r x3Am5H3Qz79CPHkrIN9YnacZnbeXVmvv85cXc8WbslJl1NWJ2xlcfd/P2feRmOIhQJEEGo MZErBcPUsTILpyte8/3lIqbkeC3nBGE= DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=suse.de; s=susede2_ed25519; t=1785111129; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=eWasTVal4kY8/UqRXzT0g5VNE+QEIsTmERV/2l89Qwk=; b=6TQh8GYFQnYjaYTgGoUNTMoesmwfU9053eSObn6itYi6XxG2RjoZnUwZZV9KRvlDOAXgm+ 0vPe63pTacQYZcAg== Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 1EB6F779B9; Mon, 27 Jul 2026 00:12:08 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id Q4VJN1iiZmr2GQAAD6G6ig (envelope-from ); Mon, 27 Jul 2026 00:12:08 +0000 From: Gabriel Krisman Bertazi To: Jens Axboe , io-uring Cc: Sung Keum Subject: Re: [PATCH] io_uring/kbuf: cap buffer selection length at MAX_RW_COUNT In-Reply-To: Organization: SUSE References: Date: Sun, 26 Jul 2026 20:12:07 -0400 Message-ID: <87v7a1cmug.fsf@mailhost.krisman.be> Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain X-Spam-Score: -4.51 X-Spam-Level: X-Rspamd-Action: no action X-Rspamd-Queue-Id: 6E27D7D867 X-Spamd-Result: default: False [-4.51 / 50.00]; BAYES_HAM(-3.00)[99.98%]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_DKIM_ALLOW(-0.20)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; MX_GOOD(-0.01)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; TO_DN_ALL(0.00)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; FREEMAIL_ENVRCPT(0.00)[gmail.com]; ARC_NA(0.00)[]; RBL_SPAMHAUS_BLOCKED_OPENRESOLVER(0.00)[2a07:de40:b281:104:10:150:64:97:from]; MIME_TRACE(0.00)[0:+]; HAS_ORG_HEADER(0.00)[]; FREEMAIL_CC(0.00)[gmail.com]; RCVD_TLS_ALL(0.00)[]; DKIM_TRACE(0.00)[suse.de:+]; RCVD_COUNT_TWO(0.00)[2]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; SPAMHAUS_XBL(0.00)[2a07:de40:b281:104:10:150:64:97:from]; DNSWL_BLOCKED(0.00)[2a07:de40:b281:104:10:150:64:97:from,2a07:de40:b281:106:10:150:64:167:received]; RCVD_VIA_SMTP_AUTH(0.00)[]; RECEIVED_SPAMHAUS_BLOCKED_OPENRESOLVER(0.00)[2a07:de40:b281:106:10:150:64:167:received]; RCPT_COUNT_THREE(0.00)[3]; MISSING_XM_UA(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[mailhost.krisman.be:mid,imap1.dmz-prg2.suse.org:helo,imap1.dmz-prg2.suse.org:rdns,suse.de:email,suse.de:dkim,kernel.dk:email] X-Rspamd-Server: rspamd1.dmz-prg2.suse.org X-Spam-Flag: NO Jens Axboe writes: > io_ring_buffers_peek() builds an iovec array from provided buffers, and > that in turn can be handed off to a lower level provider. Be prudent and > cap the total size to MAX_RW_COUNT, which is the Linux default for how > much IO do to in a single call. > > No bugs here, but it's a good preventative measure to avoid truncation > issues. > > Signed-off-by: Jens Axboe Reviewed-by: Gabriel Krisman Bertazi