Re: [PATCH] bnx2x: Fix NULL pointer dereference in bnx2x_del_all_vlans() on some hw

[Ivan Mironov]

4.20 release is affected too.

On Sun, 2018-12-23 at 20:29 +0500, Ivan Mironov wrote:
> This happened when I tried to boot normal Fedora 29 system with latest
> available kernel (from fedora rawhide, plus some unrelated custom
> patches):
> 
> 	BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
> 	PGD 0 P4D 0
> 	Oops: 0010 [#1] SMP PTI
> 	CPU: 6 PID: 1422 Comm: libvirtd Tainted: G          I       4.20.0-0.rc7.git3.hpsa2.1.fc29.x86_64 #1
> 	Hardware name: HP ProLiant BL460c G6, BIOS I24 05/21/2018
> 	RIP: 0010:          (null)
> 	Code: Bad RIP value.
> 	RSP: 0018:ffffa47ccdc9fbe0 EFLAGS: 00010246
> 	RAX: 0000000000000000 RBX: 00000000000003e8 RCX: ffffa47ccdc9fbf8
> 	RDX: ffffa47ccdc9fc00 RSI: ffff97d9ee7b01f8 RDI: ffff97d9f0150b80
> 	RBP: ffff97d9f0150b80 R08: 0000000000000000 R09: 0000000000000000
> 	R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000003
> 	R13: ffff97d9ef1e53e8 R14: 0000000000000009 R15: ffff97d9f0ac6730
> 	FS:  00007f4d224ef700(0000) GS:ffff97d9fa200000(0000) knlGS:0000000000000000
> 	CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> 	CR2: ffffffffffffffd6 CR3: 00000011ece52006 CR4: 00000000000206e0
> 	Call Trace:
> 	 ? bnx2x_chip_cleanup+0x195/0x610 [bnx2x]
> 	 ? bnx2x_nic_unload+0x1e2/0x8f0 [bnx2x]
> 	 ? bnx2x_reload_if_running+0x24/0x40 [bnx2x]
> 	 ? bnx2x_set_features+0x79/0xa0 [bnx2x]
> 	 ? __netdev_update_features+0x244/0x9e0
> 	 ? netlink_broadcast_filtered+0x136/0x4b0
> 	 ? netdev_update_features+0x22/0x60
> 	 ? dev_disable_lro+0x1c/0xe0
> 	 ? devinet_sysctl_forward+0x1c6/0x211
> 	 ? proc_sys_call_handler+0xab/0x100
> 	 ? __vfs_write+0x36/0x1a0
> 	 ? rcu_read_lock_sched_held+0x79/0x80
> 	 ? rcu_sync_lockdep_assert+0x2e/0x60
> 	 ? __sb_start_write+0x14c/0x1b0
> 	 ? vfs_write+0x159/0x1c0
> 	 ? vfs_write+0xba/0x1c0
> 	 ? ksys_write+0x52/0xc0
> 	 ? do_syscall_64+0x60/0x1f0
> 	 ? entry_SYSCALL_64_after_hwframe+0x49/0xbe
> 
> After some investigation I figured out that recently added cleanup code
> tries to call VLAN filtering de-initialization function which exist only
> for newer hardware. Corresponding function pointer is not
> initialized (== 0) for older hardware, namely these chips:
> 
> 	#define CHIP_NUM_57710			0x164e
> 	#define CHIP_NUM_57711			0x164f
> 	#define CHIP_NUM_57711E			0x1650
> 
> And I have one of those in my test system:
> 
> 	02:00.0 Ethernet controller [0200]: Broadcom Inc. and subsidiaries NetXtreme II BCM57711E 10-Gigabit PCIe [14e4:1650]
> 	02:00.1 Ethernet controller [0200]: Broadcom Inc. and subsidiaries NetXtreme II BCM57711E 10-Gigabit PCIe [14e4:1650]
> 
> Function bnx2x_init_vlan_mac_fp_objs() from
> drivers/net/ethernet/broadcom/bnx2x/bnx2x_cmn.h decides whether to
> initialize relevant pointers in bnx2x_sp_objs.vlan_obj or not.
> 
> This regression was introduced after v4.20-rc7.
> 
> Fixes: 04f05230c5c13 ("bnx2x: Remove configured vlans as part of unload sequence.")
> Signed-off-by: Ivan Mironov <mironov.ivan@xxxxxxxxx>
> ---
>  .../net/ethernet/broadcom/bnx2x/bnx2x_main.c  | 22 +++++++++++++------
>  1 file changed, 15 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
> index b164f705709d..0e37c2484ac2 100644
> --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
> +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
> @@ -8504,15 +8504,23 @@ int bnx2x_set_vlan_one(struct bnx2x *bp, u16 vlan,
>  static int bnx2x_del_all_vlans(struct bnx2x *bp)
>  {
>  	struct bnx2x_vlan_mac_obj *vlan_obj = &bp->sp_objs[0].vlan_obj;
> -	unsigned long ramrod_flags = 0, vlan_flags = 0;
>  	struct bnx2x_vlan_entry *vlan;
> -	int rc;
>  
> -	__set_bit(RAMROD_COMP_WAIT, &ramrod_flags);
> -	__set_bit(BNX2X_VLAN, &vlan_flags);
> -	rc = vlan_obj->delete_all(bp, vlan_obj, &vlan_flags, &ramrod_flags);
> -	if (rc)
> -		return rc;
> +	/* The whole *vlan_obj structure may be not initialized if VLAN
> +	 * filtering offload is not supported by hardware. Currently this is
> +	 * true for all hardware covered by CHIP_IS_E1x().
> +	 */
> +	if (vlan_obj->delete_all) {
> +		unsigned long ramrod_flags = 0, vlan_flags = 0;
> +		int rc;
> +
> +		__set_bit(RAMROD_COMP_WAIT, &ramrod_flags);
> +		__set_bit(BNX2X_VLAN, &vlan_flags);
> +		rc = vlan_obj->delete_all(bp, vlan_obj, &vlan_flags,
> +					  &ramrod_flags);
> +		if (rc)
> +			return rc;
> +	}
>  
>  	/* Mark that hw forgot all entries */
>  	list_for_each_entry(vlan, &bp->vlan_reg, link)