Userspace may ask tun device to send packet with ridiculously big header and trigger this:
------------[ cut here ]------------ WARNING: CPU: 1 PID: 15366 at mm/page_alloc.c:3548 __alloc_pages_nodemask+0x537/0x1200 order 19 >= 11, gfp 0x2044d0 Call Trace: dump_stack+0x19/0x1b __warn+0x17f/0x1c0 warn_slowpath_fmt+0xad/0xe0 __alloc_pages_nodemask+0x537/0x1200 kmalloc_large_node+0x5f/0xd0 __kmalloc_node_track_caller+0x425/0x630 __kmalloc_reserve.isra.33+0x47/0xd0 __alloc_skb+0xdd/0x5f0 alloc_skb_with_frags+0x8f/0x540 sock_alloc_send_pskb+0x5e5/0x940 tun_get_user+0x38b/0x24a0 [tun] tun_chr_aio_write+0x13a/0x250 [tun] do_sync_readv_writev+0xdf/0x1c0 do_readv_writev+0x1a5/0x850 vfs_writev+0xba/0x190 SyS_writev+0x17c/0x340 system_call_fastpath+0x25/0x2a Just add __GFP_NOWARN and silently return -ENOMEM to fix this. https://jira.sw.ru/browse/PSBM-103639 Signed-off-by: Andrey Ryabinin <aryabi...@virtuozzo.com> --- drivers/net/tun.c | 4 ++-- include/net/sock.h | 7 +++++++ net/core/sock.c | 9 +++++++++ 3 files changed, 18 insertions(+), 2 deletions(-) diff --git a/drivers/net/tun.c b/drivers/net/tun.c index e95a89ba48b7..c0879c6a9703 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1142,8 +1142,8 @@ static struct sk_buff *tun_alloc_skb(struct tun_file *tfile, if (prepad + len < PAGE_SIZE || !linear) linear = len; - skb = sock_alloc_send_pskb(sk, prepad + linear, len - linear, noblock, - &err, 0); + skb = sock_alloc_send_pskb_flags(sk, prepad + linear, len - linear, noblock, + &err, 0, __GFP_NOWARN); if (!skb) return ERR_PTR(err); diff --git a/include/net/sock.h b/include/net/sock.h index 4136d2c3080c..1912d85ecc4d 100644 --- a/include/net/sock.h +++ b/include/net/sock.h @@ -1626,6 +1626,13 @@ extern struct sk_buff *sock_alloc_send_pskb(struct sock *sk, int noblock, int *errcode, int max_page_order); +extern struct sk_buff *sock_alloc_send_pskb_flags(struct sock *sk, + unsigned long header_len, + unsigned long data_len, + int noblock, + int *errcode, + int max_page_order, + gfp_t extra_flags); extern void *sock_kmalloc(struct sock *sk, int size, gfp_t priority); extern void sock_kfree_s(struct sock *sk, void *mem, int size); diff --git a/net/core/sock.c b/net/core/sock.c index 508fc6093a26..07ea42f976cf 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1964,6 +1964,15 @@ struct sk_buff *sock_alloc_send_pskb(struct sock *sk, unsigned long header_len, } EXPORT_SYMBOL(sock_alloc_send_pskb); +struct sk_buff *sock_alloc_send_pskb_flags(struct sock *sk, unsigned long header_len, + unsigned long data_len, int noblock, + int *errcode, int max_page_order, gfp_t extra_flags) +{ + return __sock_alloc_send_pskb(sk, header_len, data_len, noblock, + errcode, max_page_order, extra_flags); +} +EXPORT_SYMBOL(sock_alloc_send_pskb_flags); + struct sk_buff *sock_alloc_send_skb(struct sock *sk, unsigned long size, int noblock, int *errcode) { -- 2.26.2 _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel