From: Eric Dumazet edumazet@google.com
[ Upstream commit a9b1110162357689a34992d5c925852948e5b9fd ]
syzbot was to trigger a bug by tricking AF_LLC with non sensible addr->sllc_arphrd
It seems clear LLC requires an Ethernet device.
Back in commit abf9d537fea2 ("llc: add support for SO_BINDTODEVICE") Octavian Purdila added possibility for application to use a zero value for sllc_arphrd, convert it to ARPHRD_ETHER to not cause regressions on existing applications.
BUG: KASAN: use-after-free in __read_once_size include/linux/compiler.h:199 [inline] BUG: KASAN: use-after-free in list_empty include/linux/list.h:268 [inline] BUG: KASAN: use-after-free in waitqueue_active include/linux/wait.h:126 [inline] BUG: KASAN: use-after-free in wq_has_sleeper include/linux/wait.h:160 [inline] BUG: KASAN: use-after-free in skwq_has_sleeper include/net/sock.h:2092 [inline] BUG: KASAN: use-after-free in sock_def_write_space+0x642/0x670 net/core/sock.c:2813 Read of size 8 at addr ffff88801e0b4078 by task ksoftirqd/3/27
CPU: 3 PID: 27 Comm: ksoftirqd/3 Not tainted 5.5.0-rc1-syzkaller #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:639 __asan_report_load8_noabort+0x14/0x20 mm/kasan/generic_report.c:135 __read_once_size include/linux/compiler.h:199 [inline] list_empty include/linux/list.h:268 [inline] waitqueue_active include/linux/wait.h:126 [inline] wq_has_sleeper include/linux/wait.h:160 [inline] skwq_has_sleeper include/net/sock.h:2092 [inline] sock_def_write_space+0x642/0x670 net/core/sock.c:2813 sock_wfree+0x1e1/0x260 net/core/sock.c:1958 skb_release_head_state+0xeb/0x260 net/core/skbuff.c:652 skb_release_all+0x16/0x60 net/core/skbuff.c:663 __kfree_skb net/core/skbuff.c:679 [inline] consume_skb net/core/skbuff.c:838 [inline] consume_skb+0xfb/0x410 net/core/skbuff.c:832 __dev_kfree_skb_any+0xa4/0xd0 net/core/dev.c:2967 dev_kfree_skb_any include/linux/netdevice.h:3650 [inline] e1000_unmap_and_free_tx_resource.isra.0+0x21b/0x3a0 drivers/net/ethernet/intel/e1000/e1000_main.c:1963 e1000_clean_tx_irq drivers/net/ethernet/intel/e1000/e1000_main.c:3854 [inline] e1000_clean+0x4cc/0x1d10 drivers/net/ethernet/intel/e1000/e1000_main.c:3796 napi_poll net/core/dev.c:6532 [inline] net_rx_action+0x508/0x1120 net/core/dev.c:6600 __do_softirq+0x262/0x98c kernel/softirq.c:292 run_ksoftirqd kernel/softirq.c:603 [inline] run_ksoftirqd+0x8e/0x110 kernel/softirq.c:595 smpboot_thread_fn+0x6a3/0xa40 kernel/smpboot.c:165 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
Allocated by task 8247: save_stack+0x23/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] __kasan_kmalloc mm/kasan/common.c:513 [inline] __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:486 kasan_slab_alloc+0xf/0x20 mm/kasan/common.c:521 slab_post_alloc_hook mm/slab.h:584 [inline] slab_alloc mm/slab.c:3320 [inline] kmem_cache_alloc+0x121/0x710 mm/slab.c:3484 sock_alloc_inode+0x1c/0x1d0 net/socket.c:240 alloc_inode+0x68/0x1e0 fs/inode.c:230 new_inode_pseudo+0x19/0xf0 fs/inode.c:919 sock_alloc+0x41/0x270 net/socket.c:560 __sock_create+0xc2/0x730 net/socket.c:1384 sock_create net/socket.c:1471 [inline] __sys_socket+0x103/0x220 net/socket.c:1513 __do_sys_socket net/socket.c:1522 [inline] __se_sys_socket net/socket.c:1520 [inline] __ia32_sys_socket+0x73/0xb0 net/socket.c:1520 do_syscall_32_irqs_on arch/x86/entry/common.c:337 [inline] do_fast_syscall_32+0x27b/0xe16 arch/x86/entry/common.c:408 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
Freed by task 17: save_stack+0x23/0x90 mm/kasan/common.c:72 set_track mm/kasan/common.c:80 [inline] kasan_set_free_info mm/kasan/common.c:335 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/common.c:474 kasan_slab_free+0xe/0x10 mm/kasan/common.c:483 __cache_free mm/slab.c:3426 [inline] kmem_cache_free+0x86/0x320 mm/slab.c:3694 sock_free_inode+0x20/0x30 net/socket.c:261 i_callback+0x44/0x80 fs/inode.c:219 __rcu_reclaim kernel/rcu/rcu.h:222 [inline] rcu_do_batch kernel/rcu/tree.c:2183 [inline] rcu_core+0x570/0x1540 kernel/rcu/tree.c:2408 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2417 __do_softirq+0x262/0x98c kernel/softirq.c:292
The buggy address belongs to the object at ffff88801e0b4000 which belongs to the cache sock_inode_cache of size 1152 The buggy address is located 120 bytes inside of 1152-byte region [ffff88801e0b4000, ffff88801e0b4480) The buggy address belongs to the page: page:ffffea0000782d00 refcount:1 mapcount:0 mapping:ffff88807aa59c40 index:0xffff88801e0b4ffd raw: 00fffe0000000200 ffffea00008e6c88 ffffea0000782d48 ffff88807aa59c40 raw: ffff88801e0b4ffd ffff88801e0b4000 0000000100000003 0000000000000000 page dumped because: kasan: bad access detected
Memory state around the buggy address: ffff88801e0b3f00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ffff88801e0b3f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff88801e0b4000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^ ffff88801e0b4080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88801e0b4100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
Fixes: abf9d537fea2 ("llc: add support for SO_BINDTODEVICE") Signed-off-by: Eric Dumazet edumazet@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/llc/af_llc.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-)
diff --git a/net/llc/af_llc.c b/net/llc/af_llc.c index c74f44dfaa22..5abb7f9b7ee5 100644 --- a/net/llc/af_llc.c +++ b/net/llc/af_llc.c @@ -273,6 +273,10 @@ static int llc_ui_autobind(struct socket *sock, struct sockaddr_llc *addr)
if (!sock_flag(sk, SOCK_ZAPPED)) goto out; + if (!addr->sllc_arphrd) + addr->sllc_arphrd = ARPHRD_ETHER; + if (addr->sllc_arphrd != ARPHRD_ETHER) + goto out; rc = -ENODEV; if (sk->sk_bound_dev_if) { llc->dev = dev_get_by_index(&init_net, sk->sk_bound_dev_if); @@ -328,7 +332,9 @@ static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen) if (unlikely(!sock_flag(sk, SOCK_ZAPPED) || addrlen != sizeof(*addr))) goto out; rc = -EAFNOSUPPORT; - if (unlikely(addr->sllc_family != AF_LLC)) + if (!addr->sllc_arphrd) + addr->sllc_arphrd = ARPHRD_ETHER; + if (unlikely(addr->sllc_family != AF_LLC || addr->sllc_arphrd != ARPHRD_ETHER)) goto out; dprintk("%s: binding %02X\n", __func__, addr->sllc_sap); rc = -ENODEV; @@ -336,8 +342,6 @@ static int llc_ui_bind(struct socket *sock, struct sockaddr *uaddr, int addrlen) if (sk->sk_bound_dev_if) { llc->dev = dev_get_by_index_rcu(&init_net, sk->sk_bound_dev_if); if (llc->dev) { - if (!addr->sllc_arphrd) - addr->sllc_arphrd = llc->dev->type; if (is_zero_ether_addr(addr->sllc_mac)) memcpy(addr->sllc_mac, llc->dev->dev_addr, IFHWADDRLEN);