• Eric Dumazet's avatar
    vlan: free percpu stats in device destructor · a48e5faf
    Eric Dumazet authored
    Madalin-Cristian reported crashs happening after a recent commit
    (5a4ae5f6 "vlan: unnecessary to check if vlan_pcpu_stats is NULL")
    
    -----------------------------------------------------------------------
    root@p5040ds:~# vconfig add eth8 1
    root@p5040ds:~# vconfig rem eth8.1
    Unable to handle kernel paging request for data at address 0x2bc88028
    Faulting instruction address: 0xc058e950
    Oops: Kernel access of bad area, sig: 11 [#1]
    SMP NR_CPUS=8 CoreNet Generic
    Modules linked in:
    CPU: 3 PID: 2167 Comm: vconfig Tainted: G        W     3.16.0-rc3-00346-g65e85bf #2
    task: e7264d90 ti: e2c2c000 task.ti: e2c2c000
    NIP: c058e950 LR: c058ea30 CTR: c058e900
    REGS: e2c2db20 TRAP: 0300   Tainted: G        W      (3.16.0-rc3-00346-g65e85bf)
    MSR: 00029002 <CE,EE,ME>  CR: 48000428  XER: 20000000
    DEAR: 2bc88028 ESR: 00000000
    GPR00: c047299c e2c2dbd0 e7264d90 00000000 2bc88000 00000000 ffffffff 00000000
    GPR08: 0000000f 00000000 000000ff 00000000 28000422 10121928 10100000 10100000
    GPR16: 10100000 00000000 c07c5968 00000000 00000000 00000000 e2c2dc48 e7838000
    GPR24: c07c5bac c07c58a8 e77290cc c07b0000 00000000 c05de6c0 e7838000 e2c2dc48
    NIP [c058e950] vlan_dev_get_stats64+0x50/0x170
    LR [c058ea30] vlan_dev_get_stats64+0x130/0x170
    Call Trace:
    [e2c2dbd0] [ffffffea] 0xffffffea (unreliable)
    [e2c2dc20] [c047299c] dev_get_stats+0x4c/0x140
    [e2c2dc40] [c0488ca8] rtnl_fill_ifinfo+0x3d8/0x960
    [e2c2dd70] [c0489f4c] rtmsg_ifinfo+0x6c/0x110
    [e2c2dd90] [c04731d4] rollback_registered_many+0x344/0x3b0
    [e2c2ddd0] [c047332c] rollback_registered+0x2c/0x50
    [e2c2ddf0] [c0476058] unregister_netdevice_queue+0x78/0xf0
    [e2c2de00] [c058d800] unregister_vlan_dev+0xc0/0x160
    [e2c2de20] [c058e360] vlan_ioctl_handler+0x1c0/0x550
    [e2c2de90] [c045d11c] sock_ioctl+0x28c/0x2f0
    [e2c2deb0] [c010d070] do_vfs_ioctl+0x90/0x7b0
    [e2c2df20] [c010d7d0] SyS_ioctl+0x40/0x80
    [e2c2df40] [c000f924] ret_from_syscall+0x0/0x3c
    
    Fix this problem by freeing percpu stats from dev->destructor() instead
    of ndo_uninit()
    Reported-by: default avatarMadalin-Cristian Bucur <madalin.bucur@freescale.com>
    Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
    Tested-by: default avatarMadalin-Cristian Bucur <madalin.bucur@freescale.com>
    Fixes: 5a4ae5f6 ("vlan: unnecessary to check if vlan_pcpu_stats is NULL")
    Cc: Li RongQing <roy.qing.li@gmail.com>
    Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
    a48e5faf
vlan_dev.c 21.7 KB