From b8bd72d3171b51bcc2c992f6f4c475949c21a2d0 Mon Sep 17 00:00:00 2001 From: Eric Dumazet Date: Mon, 1 Jul 2019 10:48:51 -0700 Subject: [PATCH] bonding/main: fix NULL dereference in bond_select_active_slave() A bonding master can be up while best_slave is NULL. [12105.636318] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 [12105.638204] mlx4_en: eth1: Linkstate event 1 -> 1 [12105.648984] IP: bond_select_active_slave+0x125/0x250 [12105.653977] PGD 0 P4D 0 [12105.656572] Oops: 0000 [#1] SMP PTI [12105.660487] gsmi: Log Shutdown Reason 0x03 [12105.664620] Modules linked in: kvm_intel loop act_mirred uhaul vfat fat stg_standard_ftl stg_megablocks stg_idt stg_hdi stg elephant_dev_num stg_idt_eeprom w1_therm wire i2c_mux_pca954x i2c_mux mlx4_i2c i2c_usb cdc_acm ehci_pci ehci_hcd i2c_iimc mlx4_en mlx4_ib ib_uverbs ib_core mlx4_core [last unloaded: kvm_intel] [12105.685686] mlx4_core 0000:03:00.0: dispatching link up event for port 2 [12105.685700] mlx4_en: eth2: Linkstate event 2 -> 1 [12105.685700] mlx4_en: eth2: Link Up (linkstate) [12105.724452] Workqueue: bond0 bond_mii_monitor [12105.728854] RIP: 0010:bond_select_active_slave+0x125/0x250 [12105.734355] RSP: 0018:ffffaf146a81fd88 EFLAGS: 00010246 [12105.739637] RAX: 0000000000000003 RBX: ffff8c62b03c6900 RCX: 0000000000000000 [12105.746838] RDX: 0000000000000000 RSI: ffffaf146a81fd08 RDI: ffff8c62b03c6000 [12105.754054] RBP: ffffaf146a81fdb8 R08: 0000000000000001 R09: ffff8c517d387600 [12105.761299] R10: 00000000001075d9 R11: ffffffffaceba92f R12: 0000000000000000 [12105.768553] R13: ffff8c8240ae4800 R14: 0000000000000000 R15: 0000000000000000 [12105.775748] FS: 0000000000000000(0000) GS:ffff8c62bfa40000(0000) knlGS:0000000000000000 [12105.783892] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [12105.789716] CR2: 0000000000000000 CR3: 0000000d0520e001 CR4: 00000000001626f0 [12105.796976] Call Trace: [12105.799446] [] bond_mii_monitor+0x497/0x6f0 [12105.805317] [] process_one_work+0x143/0x370 [12105.811225] [] worker_thread+0x4a/0x360 [12105.816761] [] kthread+0x105/0x140 [12105.821865] [] ? rescuer_thread+0x380/0x380 [12105.827757] [] ? kthread_associate_blkcg+0xc0/0xc0 [12105.834266] [] ret_from_fork+0x51/0x60 Fixes: e2a7420df2e0 ("bonding/main: convert to using slave printk macros") Signed-off-by: Eric Dumazet Reported-by: John Sperbeck Cc: Jarod Wilson CC: Jay Vosburgh CC: Veaceslav Falico CC: Andy Gospodarek Signed-off-by: David S. Miller --- drivers/net/bonding/bond_main.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c index a30595955a37..84168455aded 100644 --- a/drivers/net/bonding/bond_main.c +++ b/drivers/net/bonding/bond_main.c @@ -937,7 +937,7 @@ void bond_select_active_slave(struct bonding *bond) return; if (netif_carrier_ok(bond->dev)) - slave_info(bond->dev, best_slave->dev, "active interface up!\n"); + netdev_info(bond->dev, "active interface up!\n"); else netdev_info(bond->dev, "now running without any active interface!\n"); } -- 2.34.1