From: Pavel Skripkin <paskripkin@xxxxxxxxx> commit 093b036aa94e01a0bea31a38d7f0ee28a2749023 upstream. syzbot found WARNING in __alloc_pages_nodemask()[1] when order >= MAX_ORDER. It was caused by a huge length value passed from userspace to qrtr_tun_write_iter(), which tries to allocate skb. Since the value comes from the untrusted source there is no need to raise a warning in __alloc_pages_nodemask(). [1] WARNING in __alloc_pages_nodemask+0x5f8/0x730 mm/page_alloc.c:5014 Call Trace: __alloc_pages include/linux/gfp.h:511 [inline] __alloc_pages_node include/linux/gfp.h:524 [inline] alloc_pages_node include/linux/gfp.h:538 [inline] kmalloc_large_node+0x60/0x110 mm/slub.c:3999 __kmalloc_node_track_caller+0x319/0x3f0 mm/slub.c:4496 __kmalloc_reserve net/core/skbuff.c:150 [inline] __alloc_skb+0x4e4/0x5a0 net/core/skbuff.c:210 __netdev_alloc_skb+0x70/0x400 net/core/skbuff.c:446 netdev_alloc_skb include/linux/skbuff.h:2832 [inline] qrtr_endpoint_post+0x84/0x11b0 net/qrtr/qrtr.c:442 qrtr_tun_write_iter+0x11f/0x1a0 net/qrtr/tun.c:98 call_write_iter include/linux/fs.h:1901 [inline] new_sync_write+0x426/0x650 fs/read_write.c:518 vfs_write+0x791/0xa30 fs/read_write.c:605 ksys_write+0x12d/0x250 fs/read_write.c:658 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Reported-by: syzbot+80dccaee7c6630fa9dcf@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Pavel Skripkin <paskripkin@xxxxxxxxx> Acked-by: Alexander Lobakin <alobakin@xxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/qrtr/qrtr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/qrtr/qrtr.c +++ b/net/qrtr/qrtr.c @@ -271,7 +271,7 @@ int qrtr_endpoint_post(struct qrtr_endpo if (len == 0 || len & 3) return -EINVAL; - skb = netdev_alloc_skb(NULL, len); + skb = __netdev_alloc_skb(NULL, len, GFP_ATOMIC | __GFP_NOWARN); if (!skb) return -ENOMEM;
