From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-pf1-f178.google.com (mail-pf1-f178.google.com [209.85.210.178]) (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 293DC43172 for ; Thu, 18 Jul 2024 19:00:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.178 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721329240; cv=none; b=GRAvdRoW303/Tbm3WffLAhnRmrcp8UsxHdoZ4UhyaPRtCQFCfuLY7WEOTkhDuQuEVpteA54TGVik6owiIY03G8q11fPBsRISxAqczPpSuXaQ7z3gz39sDnj03x9X13IqDjAV7GxcRuUEPak/We8ZfxAPX4sq/KoxqO5OkW74rEw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721329240; c=relaxed/simple; bh=pfwBMSoIF7hRjnhR87XMcW+hAo3BKkh8Yb1UlDGs7oM=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=PYHkBextxESGD3dVz6M63wxHnef7Dh7l0S9iaHhsd4InfZWWNHK4WUx2Rzl2sb2ImFjlltl9eO9a9qU2/S9aOFdfJPtYtSW889BaBENILTxIKzrYoqiVUODzanBom48VeUYjuZfyhjaTJKyRMjSZKNwZaG4rcA5qjOcpBiqJ4ys= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=Q5vwy1yf; arc=none smtp.client-ip=209.85.210.178 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="Q5vwy1yf" Received: by mail-pf1-f178.google.com with SMTP id d2e1a72fcca58-70b1808dee9so128854b3a.2 for ; Thu, 18 Jul 2024 12:00:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1721329238; x=1721934038; darn=vger.kernel.org; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to; bh=PH4CPqkdlU7Ong2MyLEx6DzQ90oWG7y6TrgGwORBb94=; b=Q5vwy1yfcIinMfsaluHrkoc0leNdY9mMBioWzfKXIHxJx7bj8DrU4xf5AUWb4WYPWn 4mbLCePmdtt5sNHl8UChnSgL5LE7m4QjFdCtZkmkhrLHvsP7Bz3VZ5ixXFLXbCoWejw5 sD1F29NwptOe5Z8dLlovSVx/JYO/m2fmT6v0/mal1VFwqaDADFDd6+tdlB+ySVZAiz7C hWzC4TcGGPFOID9Wq8tzom4sERGI0Od7GgEKc+VFB+5YTwpVuqdJDR7EOS0fNdVC7jfa NhQzt+YqEYOVjl5WCx9ofx17aeSEQsXbU6BhwETJHq8dcK/SUwIXKLa52XgFk4z6zflv vBXg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1721329238; x=1721934038; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=PH4CPqkdlU7Ong2MyLEx6DzQ90oWG7y6TrgGwORBb94=; b=qj6xZsuxzxIdZz/EASzrrfAMsZJVadh5yjE/K/XrKl4JpHRps5uwmraAm68jwklGEU IVPBqFBIcSYDueut+b+y7W+jJTVJ11RvnWONv5N9+8s220/ZaMeKT0boQ5EJ43cif5sy wz53oyyYxUxAvG+XNt20o6qgGJOhkZELtqYCyWjuXp+s2FRjD3k62myfHgt07qc3Nd9C knMAjXxLFyDiG/RfSIne2u8lfrUkHAfqU0pEOI5SImOv8+HcAHdRNdFOKmppAbGU2zha +G6b9r0NEh+XDBq2cy8srje2YUlZkGfWCC/XtubDEpRrWdfII5463ap7y+4ZAORQcjoG Axzw== X-Gm-Message-State: AOJu0Yxp/1I3DCjZgBLQg89krARowuB9QuC7FSaF29Fo8Pm2w2vxG3Oe vnRBdnGHDQw4OwyXQFVNFn8UN2rBBmZ1bhgG/3O+qt/H915bzznbBywT681C X-Google-Smtp-Source: AGHT+IH/xyOX8HvO5zWL4kAc2mMzc2re4Nu4va9kcuRFKsWcA35/ykKkWDbxkzFGycBsC/fWLjcEOQ== X-Received: by 2002:a05:6a20:729b:b0:1c0:f2a5:c8dc with SMTP id adf61e73a8af0-1c3fdddaf8dmr6988236637.50.1721329236980; Thu, 18 Jul 2024 12:00:36 -0700 (PDT) Received: from 127.0.0.1localhost ([192.55.60.1]) by smtp.gmail.com with ESMTPSA id d2e1a72fcca58-70cfc7fc40bsm153984b3a.100.2024.07.18.12.00.36 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 18 Jul 2024 12:00:36 -0700 (PDT) From: Pavel Begunkov To: io-uring@vger.kernel.org Cc: Jens Axboe , asml.silence@gmail.com, syzbot+2074b1a3d447915c6f1c@syzkaller.appspotmail.com Subject: [PATCH 1/1] io_uring: fix error pbuf checking Date: Thu, 18 Jul 2024 20:00:53 +0100 Message-ID: X-Mailer: git-send-email 2.44.0 Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Syz reports a problem, which boils down to NULL vs IS_ERR inconsistent error handling in io_alloc_pbuf_ring(). KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] RIP: 0010:__io_remove_buffers+0xac/0x700 io_uring/kbuf.c:341 Call Trace: io_put_bl io_uring/kbuf.c:378 [inline] io_destroy_buffers+0x14e/0x490 io_uring/kbuf.c:392 io_ring_ctx_free+0xa00/0x1070 io_uring/io_uring.c:2613 io_ring_exit_work+0x80f/0x8a0 io_uring/io_uring.c:2844 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 Cc: stable@vger.kernel.org Reported-by: syzbot+2074b1a3d447915c6f1c@syzkaller.appspotmail.com Fixes: 87585b05757dc ("io_uring/kbuf: use vm_insert_pages() for mmap'ed pbuf ring") Signed-off-by: Pavel Begunkov --- io_uring/kbuf.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/io_uring/kbuf.c b/io_uring/kbuf.c index d2945c9c812b..c95dc1736dd9 100644 --- a/io_uring/kbuf.c +++ b/io_uring/kbuf.c @@ -657,8 +657,10 @@ static int io_alloc_pbuf_ring(struct io_ring_ctx *ctx, ring_size = reg->ring_entries * sizeof(struct io_uring_buf_ring); bl->buf_ring = io_pages_map(&bl->buf_pages, &bl->buf_nr_pages, ring_size); - if (!bl->buf_ring) + if (IS_ERR(bl->buf_ring)) { + bl->buf_ring = NULL; return -ENOMEM; + } bl->is_buf_ring = 1; bl->is_mmap = 1; -- 2.44.0