4.19-stable review patch. If anyone has any objections, please let me know.
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From: Eric Dumazet edumazet@google.com
[ Upstream commit cb88cb53badb8aeb3955ad6ce80b07b598e310b8 ]
syzbot triggered a warning [1] in __alloc_pages():
WARN_ON_ONCE_GFP(order > MAX_PAGE_ORDER, gfp)
Willem fixed a similar issue in commit c0a2a1b0d631 ("ppp: limit MRU to 64K")
Adopt the same sanity check for ppp_async_ioctl(PPPIOCSMRU)
[1]:
WARNING: CPU: 1 PID: 11 at mm/page_alloc.c:4543 __alloc_pages+0x308/0x698 mm/page_alloc.c:4543 Modules linked in: CPU: 1 PID: 11 Comm: kworker/u4:0 Not tainted 6.8.0-rc2-syzkaller-g41bccc98fb79 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023 Workqueue: events_unbound flush_to_ldisc pstate: 204000c5 (nzCv daIF +PAN -UAO -TCO -DIT -SSBS BTYPE=--) pc : __alloc_pages+0x308/0x698 mm/page_alloc.c:4543 lr : __alloc_pages+0xc8/0x698 mm/page_alloc.c:4537 sp : ffff800093967580 x29: ffff800093967660 x28: ffff8000939675a0 x27: dfff800000000000 x26: ffff70001272ceb4 x25: 0000000000000000 x24: ffff8000939675c0 x23: 0000000000000000 x22: 0000000000060820 x21: 1ffff0001272ceb8 x20: ffff8000939675e0 x19: 0000000000000010 x18: ffff800093967120 x17: ffff800083bded5c x16: ffff80008ac97500 x15: 0000000000000005 x14: 1ffff0001272cebc x13: 0000000000000000 x12: 0000000000000000 x11: ffff70001272cec1 x10: 1ffff0001272cec0 x9 : 0000000000000001 x8 : ffff800091c91000 x7 : 0000000000000000 x6 : 000000000000003f x5 : 00000000ffffffff x4 : 0000000000000000 x3 : 0000000000000020 x2 : 0000000000000008 x1 : 0000000000000000 x0 : ffff8000939675e0 Call trace: __alloc_pages+0x308/0x698 mm/page_alloc.c:4543 __alloc_pages_node include/linux/gfp.h:238 [inline] alloc_pages_node include/linux/gfp.h:261 [inline] __kmalloc_large_node+0xbc/0x1fc mm/slub.c:3926 __do_kmalloc_node mm/slub.c:3969 [inline] __kmalloc_node_track_caller+0x418/0x620 mm/slub.c:4001 kmalloc_reserve+0x17c/0x23c net/core/skbuff.c:590 __alloc_skb+0x1c8/0x3d8 net/core/skbuff.c:651 __netdev_alloc_skb+0xb8/0x3e8 net/core/skbuff.c:715 netdev_alloc_skb include/linux/skbuff.h:3235 [inline] dev_alloc_skb include/linux/skbuff.h:3248 [inline] ppp_async_input drivers/net/ppp/ppp_async.c:863 [inline] ppp_asynctty_receive+0x588/0x186c drivers/net/ppp/ppp_async.c:341 tty_ldisc_receive_buf+0x12c/0x15c drivers/tty/tty_buffer.c:390 tty_port_default_receive_buf+0x74/0xac drivers/tty/tty_port.c:37 receive_buf drivers/tty/tty_buffer.c:444 [inline] flush_to_ldisc+0x284/0x6e4 drivers/tty/tty_buffer.c:494 process_one_work+0x694/0x1204 kernel/workqueue.c:2633 process_scheduled_works kernel/workqueue.c:2706 [inline] worker_thread+0x938/0xef4 kernel/workqueue.c:2787 kthread+0x288/0x310 kernel/kthread.c:388 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:860
Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-and-tested-by: syzbot+c5da1f087c9e4ec6c933@syzkaller.appspotmail.com Signed-off-by: Eric Dumazet edumazet@google.com Reviewed-by: Willem de Bruijn willemb@google.com Link: https://lore.kernel.org/r/20240205171004.1059724-1-edumazet@google.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ppp/ppp_async.c | 4 ++++ 1 file changed, 4 insertions(+)
diff --git a/drivers/net/ppp/ppp_async.c b/drivers/net/ppp/ppp_async.c index bf03db40d4f0..fb1e28a29892 100644 --- a/drivers/net/ppp/ppp_async.c +++ b/drivers/net/ppp/ppp_async.c @@ -474,6 +474,10 @@ ppp_async_ioctl(struct ppp_channel *chan, unsigned int cmd, unsigned long arg) case PPPIOCSMRU: if (get_user(val, p)) break; + if (val > U16_MAX) { + err = -EINVAL; + break; + } if (val < PPP_MRU) val = PPP_MRU; ap->mru = val;