From patchwork Thu Dec 12 22:22:47 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eric Dumazet X-Patchwork-Id: 13906068 X-Patchwork-Delegate: kuba@kernel.org Received: from mail-qk1-f201.google.com (mail-qk1-f201.google.com [209.85.222.201]) (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 1B472199FD3 for ; Thu, 12 Dec 2024 22:22:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.222.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734042171; cv=none; b=aPaGp29vZ03gNdG9zt8iK+u4MC8jORJ+WB6CQFFd31C0Z2tAY3bCzjzFPFz5X9zYrswrK1UcDmLt9iUAL2oHlkLbXaphFpkSZ+A4nDOUTbbp/KRs8qfZMXdmrPodwpYrrvW7F95JzfpXFEmg98Iv4t+y/ed70+WPJzy/GgnM8x4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734042171; c=relaxed/simple; bh=mYR85XkPv99mgY49elAAtDmoBwLsFWrGRtjvzlV2lMw=; h=Date:Mime-Version:Message-ID:Subject:From:To:Cc:Content-Type; b=bl1KYq4br+v9QDmXXg+e039CkId4U3YJAV8NSpqgnq2smSuqUdk6xA4FYghdSLFnRXLyPKZv60iEDDEzloPpzrXaVXYIfUD5u8hKvyBDiM9ZpggA9W6D4BJML+cuVlwGbkK8cyLXVf5a6rIdvOMR8jZLwkXd1u0SmylmYd0SzQw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=QwJuupoJ; arc=none smtp.client-ip=209.85.222.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--edumazet.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="QwJuupoJ" Received: by mail-qk1-f201.google.com with SMTP id af79cd13be357-7b6e241d34eso143691785a.0 for ; Thu, 12 Dec 2024 14:22:49 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1734042169; x=1734646969; darn=vger.kernel.org; h=cc:to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=mEPfB9th6277+hdPLAjftJ4fYSDwY+ol/KJ9uoK9pPQ=; b=QwJuupoJcBmT+4VDDBJHrFRnzDON6GUAekzM5/1+EE5ALtdn2THHmUPWocx9EU89CA LN+PvZjHE4hv6RDPoWhNqZ/JXIyAP11gHH+JuhyysEGdWWiNs/nZ3bMt6F3So1Q03dRC 5aZaf3OCf4RWxcbdAFkCDR3Eq1ym7M/SanTbI6YSgkLtcf+jonkIHU/RR+AWMFX89hUK V7QRpsAMLSlVoavGrepobw2YxfLxoHO94lorpSqzhv4jWAnLlNlcDb62HjsTW0O5JlWW +KxORWsp6nIF0NIn4g/uMEzEK7dsV0/jh5Kfm1z7yBvdt63O1WGe7Ytu4roVjnC2BTvB tpbw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1734042169; x=1734646969; h=cc:to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=mEPfB9th6277+hdPLAjftJ4fYSDwY+ol/KJ9uoK9pPQ=; b=L5FM/q3bt60xctB1XR9c+FTbxhWynw/L3CQQwacFNlOvFU+NklN8ME1RbHA8bk51qJ ngUuo112vTFk7u52qOtZZk0sO9F4w7pAyI4aXhA7jI8BEgDsNvlfmD99bpbm49bz57nS USbQKRcA/4q4pkSg16oczTW36juwm3i9nKKg38a0umvYr7ExA0oC/Kl2TfMU7tD0+A47 QzKv0N/NXuMTykfzm9830RImaBumoU2ZaIZ/Y6FyYzU8JJP3WVympDko4BbWADMVd0eV 70Nqo7YrfntPO14/I8CTyFpud8KKVIdzBxagohcZuCtSwU3evdfxxHcObYijr8uisiUS TgqA== X-Gm-Message-State: AOJu0YzOaJOTYkryRl1snn1p7BhgnnVj5YaLgSJyKAvJA9lPpHHbcUp6 2c+xgqojgdI2pW2DN7x9mYEeV2ijDPr8yegzZbq99okeR7uMye+LWmz+fGFYecatFcJdVtADWGX 8hayqCMRcTg== X-Google-Smtp-Source: AGHT+IG3QKcT19u3tKue7Af++4n+trcy46qQ2b0EAFNosiBK/eJ754xf5sUvQqp2hsksG9PM0K6tME4nWOHiQg== X-Received: from qkpn21.prod.google.com ([2002:a05:620a:2955:b0:7b6:e209:1c29]) (user=edumazet job=prod-delivery.src-stubby-dispatcher) by 2002:a05:620a:27cc:b0:7b6:c540:9531 with SMTP id af79cd13be357-7b6fbee746bmr25541885a.18.1734042169099; Thu, 12 Dec 2024 14:22:49 -0800 (PST) Date: Thu, 12 Dec 2024 22:22:47 +0000 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.47.1.613.gc27f4b7a9f-goog Message-ID: <20241212222247.724674-1-edumazet@google.com> Subject: [PATCH net] net: tun: fix tun_napi_alloc_frags() From: Eric Dumazet To: "David S . Miller" , Jakub Kicinski , Paolo Abeni Cc: netdev@vger.kernel.org, Simon Horman , eric.dumazet@gmail.com, Eric Dumazet , syzbot+4f66250f6663c0c1d67e@syzkaller.appspotmail.com, stable@vger.kernel.org, Jens Axboe X-Patchwork-Delegate: kuba@kernel.org syzbot reported the following crash [1] Issue came with the blamed commit. Instead of going through all the iov components, we keep using the first one and end up with a malformed skb. [1] kernel BUG at net/core/skbuff.c:2849 ! Oops: invalid opcode: 0000 [#1] PREEMPT SMP KASAN PTI CPU: 0 UID: 0 PID: 6230 Comm: syz-executor132 Not tainted 6.13.0-rc1-syzkaller-00407-g96b6fcc0ee41 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/25/2024 RIP: 0010:__pskb_pull_tail+0x1568/0x1570 net/core/skbuff.c:2848 Code: 38 c1 0f 8c 32 f1 ff ff 4c 89 f7 e8 92 96 74 f8 e9 25 f1 ff ff e8 e8 ae 09 f8 48 8b 5c 24 08 e9 eb fb ff ff e8 d9 ae 09 f8 90 <0f> 0b 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90004cbef30 EFLAGS: 00010293 RAX: ffffffff8995c347 RBX: 00000000fffffff2 RCX: ffff88802cf45a00 RDX: 0000000000000000 RSI: 00000000fffffff2 RDI: 0000000000000000 RBP: ffff88807df0c06a R08: ffffffff8995b084 R09: 1ffff1100fbe185c R10: dffffc0000000000 R11: ffffed100fbe185d R12: ffff888076e85d50 R13: ffff888076e85c80 R14: ffff888076e85cf4 R15: ffff888076e85c80 FS: 00007f0dca6ea6c0(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0dca6ead58 CR3: 00000000119da000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: skb_cow_data+0x2da/0xcb0 net/core/skbuff.c:5284 tipc_aead_decrypt net/tipc/crypto.c:894 [inline] tipc_crypto_rcv+0x402/0x24e0 net/tipc/crypto.c:1844 tipc_rcv+0x57e/0x12a0 net/tipc/node.c:2109 tipc_l2_rcv_msg+0x2bd/0x450 net/tipc/bearer.c:668 __netif_receive_skb_list_ptype net/core/dev.c:5720 [inline] __netif_receive_skb_list_core+0x8b7/0x980 net/core/dev.c:5762 __netif_receive_skb_list net/core/dev.c:5814 [inline] netif_receive_skb_list_internal+0xa51/0xe30 net/core/dev.c:5905 gro_normal_list include/net/gro.h:515 [inline] napi_complete_done+0x2b5/0x870 net/core/dev.c:6256 napi_complete include/linux/netdevice.h:567 [inline] tun_get_user+0x2ea0/0x4890 drivers/net/tun.c:1982 tun_chr_write_iter+0x10d/0x1f0 drivers/net/tun.c:2057 do_iter_readv_writev+0x600/0x880 vfs_writev+0x376/0xba0 fs/read_write.c:1050 do_writev+0x1b6/0x360 fs/read_write.c:1096 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: de4f5fed3f23 ("iov_iter: add iter_iovec() helper") Reported-by: syzbot+4f66250f6663c0c1d67e@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/675b61aa.050a0220.599f4.00bb.GAE@google.com/T/#u Cc: stable@vger.kernel.org Signed-off-by: Eric Dumazet Cc: Jens Axboe Reviewed-by: Joe Damato Reviewed-by: Jens Axboe Acked-by: Willem de Bruijn Acked-by: Michael S. Tsirkin --- drivers/net/tun.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index d7a865ef370b6968c095510ae16b5196e30e54b9..e816aaba8e5f2ed06f8832f79553b6c976e75bb8 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1481,7 +1481,7 @@ static struct sk_buff *tun_napi_alloc_frags(struct tun_file *tfile, skb->truesize += skb->data_len; for (i = 1; i < it->nr_segs; i++) { - const struct iovec *iov = iter_iov(it); + const struct iovec *iov = iter_iov(it) + i; size_t fragsz = iov->iov_len; struct page *page; void *frag;