3.16.66-rc1 review patch. If anyone has any objections, please let me know.
------------------
From: Christoph Paasch <cpaasch@xxxxxxxxx>
commit 398f0132c14754fcd03c1c4f8e7176d001ce8ea1 upstream.
Since commit fc62814d690c ("net/packet: fix 4gb buffer limit due to overflow check")
one can now allocate packet ring buffers >= UINT_MAX. However, syzkaller
found that that triggers a warning:
[ 21.100000] WARNING: CPU: 2 PID: 2075 at mm/page_alloc.c:4584 __alloc_pages_nod0
[ 21.101490] Modules linked in:
[ 21.101921] CPU: 2 PID: 2075 Comm: syz-executor.0 Not tainted 5.0.0 #146
[ 21.102784] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 0.5.1 01/01/2011
[ 21.103887] RIP: 0010:__alloc_pages_nodemask+0x2a0/0x630
[ 21.104640] Code: fe ff ff 65 48 8b 04 25 c0 de 01 00 48 05 90 0f 00 00 41 bd 01 00 00 00 48 89 44 24 48 e9 9c fe 3
[ 21.107121] RSP: 0018:ffff88805e1cf920 EFLAGS: 00010246
[ 21.107819] RAX: 0000000000000000 RBX: ffffffff85a488a0 RCX: 0000000000000000
[ 21.108753] RDX: 0000000000000000 RSI: dffffc0000000000 RDI: 0000000000000000
[ 21.109699] RBP: 1ffff1100bc39f28 R08: ffffed100bcefb67 R09: ffffed100bcefb67
[ 21.110646] R10: 0000000000000001 R11: ffffed100bcefb66 R12: 000000000000000d
[ 21.111623] R13: 0000000000000000 R14: ffff88805e77d888 R15: 000000000000000d
[ 21.112552] FS: 00007f7c7de05700(0000) GS:ffff88806d100000(0000) knlGS:0000000000000000
[ 21.113612] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 21.114405] CR2: 000000000065c000 CR3: 000000005e58e006 CR4: 00000000001606e0
[ 21.115367] Call Trace:
[ 21.115705] ? __alloc_pages_slowpath+0x21c0/0x21c0
[ 21.116362] alloc_pages_current+0xac/0x1e0
[ 21.116923] kmalloc_order+0x18/0x70
[ 21.117393] kmalloc_order_trace+0x18/0x110
[ 21.117949] packet_set_ring+0x9d5/0x1770
[ 21.118524] ? packet_rcv_spkt+0x440/0x440
[ 21.119094] ? lock_downgrade+0x620/0x620
[ 21.119646] ? __might_fault+0x177/0x1b0
[ 21.120177] packet_setsockopt+0x981/0x2940
[ 21.120753] ? __fget+0x2fb/0x4b0
[ 21.121209] ? packet_release+0xab0/0xab0
[ 21.121740] ? sock_has_perm+0x1cd/0x260
[ 21.122297] ? selinux_secmark_relabel_packet+0xd0/0xd0
[ 21.123013] ? __fget+0x324/0x4b0
[ 21.123451] ? selinux_netlbl_socket_setsockopt+0x101/0x320
[ 21.124186] ? selinux_netlbl_sock_rcv_skb+0x3a0/0x3a0
[ 21.124908] ? __lock_acquire+0x529/0x3200
[ 21.125453] ? selinux_socket_setsockopt+0x5d/0x70
[ 21.126075] ? __sys_setsockopt+0x131/0x210
[ 21.126533] ? packet_release+0xab0/0xab0
[ 21.127004] __sys_setsockopt+0x131/0x210
[ 21.127449] ? kernel_accept+0x2f0/0x2f0
[ 21.127911] ? ret_from_fork+0x8/0x50
[ 21.128313] ? do_raw_spin_lock+0x11b/0x280
[ 21.128800] __x64_sys_setsockopt+0xba/0x150
[ 21.129271] ? lockdep_hardirqs_on+0x37f/0x560
[ 21.129769] do_syscall_64+0x9f/0x450
[ 21.130182] entry_SYSCALL_64_after_hwframe+0x49/0xbe
We should allocate with __GFP_NOWARN to handle this.
Cc: Kal Conley <kal.conley@xxxxxxxxxxx>
Cc: Andrey Konovalov <andreyknvl@xxxxxxxxxx>
Fixes: fc62814d690c ("net/packet: fix 4gb buffer limit due to overflow check")
Signed-off-by: Christoph Paasch <cpaasch@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
net/packet/af_packet.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -3828,7 +3828,7 @@ static struct pgv *alloc_pg_vec(struct t
struct pgv *pg_vec;
int i;
- pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL);
+ pg_vec = kcalloc(block_nr, sizeof(struct pgv), GFP_KERNEL | __GFP_NOWARN);
if (unlikely(!pg_vec))
goto out;
