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    Subject[PATCH 4.19 006/133] llc: make sure applications use ARPHRD_ETHER
    Date
    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(-)

    --- a/net/llc/af_llc.c
    +++ b/net/llc/af_llc.c
    @@ -273,6 +273,10 @@ static int llc_ui_autobind(struct socket

    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);
    @@ -330,15 +334,15 @@ static int llc_ui_bind(struct socket *so
    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;
    rc = -ENODEV;
    rcu_read_lock();
    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);

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      Last update: 2020-07-20 19:10    [W:3.596 / U:0.008 seconds]
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