• Eric Dumazet's avatar
    ipv4: ensure rcu_read_lock() in ipv4_link_failure() · 5b4261ca
    Eric Dumazet authored
    BugLink: https://bugs.launchpad.net/bugs/1828420
    
    [ Upstream commit c543cb4a ]
    
    fib_compute_spec_dst() needs to be called under rcu protection.
    
    syzbot reported :
    
    WARNING: suspicious RCU usage
    5.1.0-rc4+ #165 Not tainted
    include/linux/inetdevice.h:220 suspicious rcu_dereference_check() usage!
    
    other info that might help us debug this:
    
    rcu_scheduler_active = 2, debug_locks = 1
    1 lock held by swapper/0/0:
     #0: 0000000051b67925 ((&n->timer)){+.-.}, at: lockdep_copy_map include/linux/lockdep.h:170 [inline]
     #0: 0000000051b67925 ((&n->timer)){+.-.}, at: call_timer_fn+0xda/0x720 kernel/time/timer.c:1315
    
    stack backtrace:
    CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.1.0-rc4+ #165
    Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
    Call Trace:
     <IRQ>
     __dump_stack lib/dump_stack.c:77 [inline]
     dump_stack+0x172/0x1f0 lib/dump_stack.c:113
     lockdep_rcu_suspicious+0x153/0x15d kernel/locking/lockdep.c:5162
     __in_dev_get_rcu include/linux/inetdevice.h:220 [inline]
     fib_compute_spec_dst+0xbbd/0x1030 net/ipv4/fib_frontend.c:294
     spec_dst_fill net/ipv4/ip_options.c:245 [inline]
     __ip_options_compile+0x15a7/0x1a10 net/ipv4/ip_options.c:343
     ipv4_link_failure+0x172/0x400 net/ipv4/route.c:1195
     dst_link_failure include/net/dst.h:427 [inline]
     arp_error_report+0xd1/0x1c0 net/ipv4/arp.c:297
     neigh_invalidate+0x24b/0x570 net/core/neighbour.c:995
     neigh_timer_handler+0xc35/0xf30 net/core/neighbour.c:1081
     call_timer_fn+0x190/0x720 kernel/time/timer.c:1325
     expire_timers kernel/time/timer.c:1362 [inline]
     __run_timers kernel/time/timer.c:1681 [inline]
     __run_timers kernel/time/timer.c:1649 [inline]
     run_timer_softirq+0x652/0x1700 kernel/time/timer.c:1694
     __do_softirq+0x266/0x95a kernel/softirq.c:293
     invoke_softirq kernel/softirq.c:374 [inline]
     irq_exit+0x180/0x1d0 kernel/softirq.c:414
     exiting_irq arch/x86/include/asm/apic.h:536 [inline]
     smp_apic_timer_interrupt+0x14a/0x570 arch/x86/kernel/apic/apic.c:1062
     apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
    
    Fixes: ed0de45a ("ipv4: recompile ip options in ipv4_link_failure")
    Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
    Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
    Cc: Stephen Suryaputra <ssuryaextr@gmail.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
    Signed-off-by: default avatarKleber Sacilotto de Souza <kleber.souza@canonical.com>
    Signed-off-by: default avatarStefan Bader <stefan.bader@canonical.com>
    5b4261ca
route.c 72.8 KB