-----Original Message----- From: Ivan Mironov [mailto:mironov.i...@gmail.com] Sent: 24 December 2018 17:26 To: netdev@vger.kernel.org Cc: Ariel Elior <ariel.el...@cavium.com>; Sudarsana Kalluru <sudarsana.kall...@cavium.com>; everest-linux...@cavium.com; David S. Miller <da...@davemloft.net>; linux-ker...@vger.kernel.org; Ivan Mironov <mironov.i...@gmail.com> Subject: [EXT] [PATCH v1] bnx2x: Fix NULL pointer dereference in bnx2x_del_all_vlans() on some hw
External Email ---------------------------------------------------------------------- External Email 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 set (== 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: 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, and still exists in v4.20 release. Fixes: 04f05230c5c13 ("bnx2x: Remove configured vlans as part of unload sequence.") Signed-off-by: Ivan Mironov <mironov.i...@gmail.com> --- v1: - Check for chip num instead of (vlan_obj->delete_all != 0). v0: - Patch introduced. --- .../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..4d72e9948a58 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 (!CHIP_IS_E1x(bp)) { + 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) -- 2.20.1 Thanks a lot for root-causing the issue and the patch. Another (simpler) way to address this would be to invoke bnx2x_del_all_vlans() only for the newer chips, e.g., + if (!CHIP_IS_E1(bp)) { /* Remove all currently configured VLANs */ rc = bnx2x_del_all_vlans(bp); if (rc < 0) BNX2X_ERR("Failed to delete all VLANs\n"); + } Could you please check on this?