From dc6311dd2a8fb9a65c1b5b94abec97bdd94cfae6 Mon Sep 17 00:00:00 2001 From: Maurizio Lombardi Date: Fri, 7 Nov 2014 12:55:39 +0100 Subject: [PATCH] bnx2fc: fix tgt spinlock locking bnx2fc_queuecommand(): when allocating a new io_req, the tgt_lock spinlock must be locked before calling bnx2fc_cmd_alloc(). The spinlock should also be kept locked until bnx2fc_post_io_req() has been completed. If not, a kernel thread may call bnx2fc_process_cq_compl() that extracts the newly allocated io_req from hba->cmd_mgr->cmds and destroys it while it is still being used by bnx2fc_post_io_req(). BUG: unable to handle kernel NULL pointer dereference at 000000000000004c IP: [] bnx2fc_init_task+0x6a/0x230 [bnx2fc] PGD 0 Oops: 0000 [#1] SMP last sysfs file: /sys/devices/pci0000:00/0000:00:02.0/0000:04:00.3/net/eth3/type CPU 33 Modules linked in: autofs4 target_core_iblock target_core_file target_core_pscsi target_core_mod configfs bnx2fc cnic uio fcoe libfcoe libfc scsi_transport_fc 8021q garp scsi_tgt stp llc cpufreq_ondemand freq_table pcc_cpufreq ipt_REJECT nf_conntrack_ipv4 nf_defrag_ipv4 iptable_filter ip_tables ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 xt_state nf_conntrack ip6table_filter ip6_tables ipv6 power_meter microcode iTCO_wdt iTCO_vendor_support hpilo hpwdt sg bnx2x libcrc32c mdio serio_raw lpc_ich mfd_core shpchp ext4 jbd2 mbcache sd_mod crc_t10dif hpsa video output dm_mirror dm_region_hash dm_log dm_mod [last unloaded: scsi_wait_scan] Pid: 7355, comm: bnx2fc_thread/3 Not tainted 2.6.32-431.el6.x86_64 #1 HP ProLiant BL460c Gen8 RIP: 0010:[] [] bnx2fc_init_task+0x6a/0x230 [bnx2fc] RSP: 0018:ffff8820b0da3b68 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff882003801080 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff882003801100 RBP: ffff8820b0da3bc8 R08: ffffffff8160d4e8 R09: 0000000000000040 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88400e600e00 R13: ffff8840108fbe40 R14: ffff88200ffe5400 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8820b0da0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b CR2: 000000000000004c CR3: 0000002010b67000 CR4: 00000000001407e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process bnx2fc_thread/3 (pid: 7355, threadinfo ffff88401f940000, task ffff884012f5f540) Stack: ffff8820b0da3bc8 ffffffff81527303 ffff884000000020 ffff8820b0da3bd8 ffff8820b0da3b98 000000028138931a ffff88400f506078 ffff88400e600e00 ffff88200ffe5400 ffff88200ffe5590 0000000000000021 0000000000000002 Call Trace: [] ? printk+0x41/0x46 [] bnx2fc_post_io_req+0x11c/0x440 [bnx2fc] [] ? cpumask_next_and+0x29/0x50 [] ? scsi_done+0x0/0x60 [] bnx2fc_queuecommand+0x117/0x140 [bnx2fc] [] scsi_dispatch_cmd+0xe5/0x310 [] scsi_request_fn+0x5ee/0x7a0 [] __blk_run_queue+0x31/0x40 [] blk_run_queue+0x30/0x50 [] scsi_run_queue+0xc6/0x270 [] ? elv_requeue_request+0x52/0xa0 [] scsi_requeue_command+0x90/0xb0 [] scsi_io_completion+0x154/0x6c0 [] scsi_finish_command+0xc2/0x130 [] scsi_softirq_done+0x145/0x170 [] blk_done_softirq+0x85/0xa0 [] __do_softirq+0xc1/0x1e0 [] ? call_softirq+0x1c/0x30 [] call_softirq+0x1c/0x30 [] ? do_softirq+0x65/0xa0 [] local_bh_enable_ip+0x9a/0xb0 [] _spin_unlock_bh+0x1b/0x20 [] bnx2fc_process_cq_compl+0x257/0x2b0 [bnx2fc] [] bnx2fc_percpu_io_thread+0xea/0x160 [bnx2fc] [] ? bnx2fc_percpu_io_thread+0x0/0x160 [bnx2fc] [] kthread+0x96/0xa0 [] child_rip+0xa/0x20 [] ? kthread+0x0/0xa0 [] ? child_rip+0x0/0x20 Code: 89 df 45 8b 7e 30 0f 85 75 01 00 00 89 d1 31 c0 c1 e9 03 83 e2 04 89 c9 f3 48 ab 74 06 c7 07 00 00 00 00 49 89 9c 24 88 01 00 00 <83> 7e 4c 01 b8 01 00 00 00 0f 84 e7 00 00 00 89 c2 0a 53 38 41 RIP [] bnx2fc_init_task+0x6a/0x230 [bnx2fc] RSP CR2: 000000000000004c Signed-off-by: Maurizio Lombardi Acked-by: Chad Dupuis Signed-off-by: Christoph Hellwig --- drivers/scsi/bnx2fc/bnx2fc_els.c | 2 -- drivers/scsi/bnx2fc/bnx2fc_io.c | 19 ++++++++++--------- 2 files changed, 10 insertions(+), 11 deletions(-) diff --git a/drivers/scsi/bnx2fc/bnx2fc_els.c b/drivers/scsi/bnx2fc/bnx2fc_els.c index ca75c7ca2559..ef355c13ccc4 100644 --- a/drivers/scsi/bnx2fc/bnx2fc_els.c +++ b/drivers/scsi/bnx2fc/bnx2fc_els.c @@ -480,9 +480,7 @@ void bnx2fc_rec_compl(struct bnx2fc_els_cb_arg *cb_arg) bnx2fc_initiate_cleanup(orig_io_req); /* Post a new IO req with the same sc_cmd */ BNX2FC_IO_DBG(rec_req, "Post IO request again\n"); - spin_unlock_bh(&tgt->tgt_lock); rc = bnx2fc_post_io_req(tgt, new_io_req); - spin_lock_bh(&tgt->tgt_lock); if (!rc) goto free_frame; BNX2FC_IO_DBG(rec_req, "REC: io post err\n"); diff --git a/drivers/scsi/bnx2fc/bnx2fc_io.c b/drivers/scsi/bnx2fc/bnx2fc_io.c index 0679782d9d15..5b99844ef6bf 100644 --- a/drivers/scsi/bnx2fc/bnx2fc_io.c +++ b/drivers/scsi/bnx2fc/bnx2fc_io.c @@ -1894,18 +1894,24 @@ int bnx2fc_queuecommand(struct Scsi_Host *host, goto exit_qcmd; } } + + spin_lock_bh(&tgt->tgt_lock); + io_req = bnx2fc_cmd_alloc(tgt); if (!io_req) { rc = SCSI_MLQUEUE_HOST_BUSY; - goto exit_qcmd; + goto exit_qcmd_tgtlock; } io_req->sc_cmd = sc_cmd; if (bnx2fc_post_io_req(tgt, io_req)) { printk(KERN_ERR PFX "Unable to post io_req\n"); rc = SCSI_MLQUEUE_HOST_BUSY; - goto exit_qcmd; + goto exit_qcmd_tgtlock; } + +exit_qcmd_tgtlock: + spin_unlock_bh(&tgt->tgt_lock); exit_qcmd: return rc; } @@ -2020,6 +2026,8 @@ int bnx2fc_post_io_req(struct bnx2fc_rport *tgt, int task_idx, index; u16 xid; + /* bnx2fc_post_io_req() is called with the tgt_lock held */ + /* Initialize rest of io_req fields */ io_req->cmd_type = BNX2FC_SCSI_CMD; io_req->port = port; @@ -2047,9 +2055,7 @@ int bnx2fc_post_io_req(struct bnx2fc_rport *tgt, /* Build buffer descriptor list for firmware from sg list */ if (bnx2fc_build_bd_list_from_sg(io_req)) { printk(KERN_ERR PFX "BD list creation failed\n"); - spin_lock_bh(&tgt->tgt_lock); kref_put(&io_req->refcount, bnx2fc_cmd_release); - spin_unlock_bh(&tgt->tgt_lock); return -EAGAIN; } @@ -2061,19 +2067,15 @@ int bnx2fc_post_io_req(struct bnx2fc_rport *tgt, task = &(task_page[index]); bnx2fc_init_task(io_req, task); - spin_lock_bh(&tgt->tgt_lock); - if (tgt->flush_in_prog) { printk(KERN_ERR PFX "Flush in progress..Host Busy\n"); kref_put(&io_req->refcount, bnx2fc_cmd_release); - spin_unlock_bh(&tgt->tgt_lock); return -EAGAIN; } if (!test_bit(BNX2FC_FLAG_SESSION_READY, &tgt->flags)) { printk(KERN_ERR PFX "Session not ready...post_io\n"); kref_put(&io_req->refcount, bnx2fc_cmd_release); - spin_unlock_bh(&tgt->tgt_lock); return -EAGAIN; } @@ -2091,6 +2093,5 @@ int bnx2fc_post_io_req(struct bnx2fc_rport *tgt, /* Ring doorbell */ bnx2fc_ring_doorbell(tgt); - spin_unlock_bh(&tgt->tgt_lock); return 0; }