[PATCH] scsi: myrs: add a check against null pointer dereference
From: Zheyu Ma
Date: Mon Jun 14 2021 - 05:25:48 EST
In the process of driver loading, the driver may fail at the place of
'myrs_enable_mmio_mbox', resulting in calling the 'myrs_cleanup'
function, but at this time, 'cs->disable' has not been assigned, so a
null pointer dereference is caused.
Fix this by check whether 'cs->disable_intr' is a null pointer.
This log reveals it:
[ 2.777884] BUG: kernel NULL pointer dereference, address: 0000000000000000
[ 2.778357] #PF: supervisor instruction fetch in kernel mode
[ 2.778742] #PF: error_code(0x0010) - not-present page
[ 2.779093] PGD 0 P4D 0
[ 2.779272] Oops: 0010 [#1] PREEMPT SMP PTI
[ 2.779560] CPU: 3 PID: 1 Comm: swapper/0 Not tainted 5.12.4-g70e7f0549188-dirty #103
[ 2.780090] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
[ 2.780885] RIP: 0010:0x0
[ 2.781077] Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
[ 2.781538] RSP: 0000:ffffc90000017b60 EFLAGS: 00010293
[ 2.781893] RAX: ffff8881001e0000 RBX: ffff888107a7cdb0 RCX: 0000000000000000
[ 2.782376] RDX: 0000000000000000 RSI: ffffffff824409c6 RDI: ffff888107a7cdb0
[ 2.782803] RBP: ffffc90000017b80 R08: 0000000000000001 R09: 0000000000000001
[ 2.782803] R10: 0000000000000000 R11: 0000000000000001 R12: ffff888101c34000
[ 2.782803] R13: ffff888007840000 R14: ffffc90000091000 R15: ffffffff82443300
[ 2.782803] FS: 0000000000000000(0000) GS:ffff88817bcc0000(0000) knlGS:0000000000000000
[ 2.782803] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2.782803] CR2: ffffffffffffffd6 CR3: 0000000005e2e000 CR4: 00000000000006e0
[ 2.782803] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 2.782803] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 2.782803] Call Trace:
[ 2.782803] myrs_cleanup+0x10f/0x190
[ 2.782803] myrs_probe+0x839/0xa20
[ 2.782803] ? kcov_remote_start+0x17b/0x430
[ 2.782803] ? trace_hardirqs_on+0x55/0x130
[ 2.782803] ? _raw_spin_unlock_irqrestore+0x35/0x5d
[ 2.782803] local_pci_probe+0x4a/0xb0
[ 2.782803] ? local_pci_probe+0x4a/0xb0
[ 2.782803] pci_device_probe+0x126/0x1d0
[ 2.782803] ? pci_device_remove+0x100/0x100
[ 2.782803] really_probe+0x27e/0x650
[ 2.782803] driver_probe_device+0x84/0x1d0
[ 2.782803] ? mutex_lock_nested+0x16/0x20
[ 2.782803] device_driver_attach+0x63/0x70
[ 2.782803] __driver_attach+0x117/0x1a0
[ 2.782803] ? device_driver_attach+0x70/0x70
[ 2.782803] bus_for_each_dev+0xb6/0x110
[ 2.782803] ? rdinit_setup+0x40/0x40
[ 2.782803] driver_attach+0x22/0x30
[ 2.782803] bus_add_driver+0x1e6/0x2a0
[ 2.782803] driver_register+0xa4/0x180
[ 2.782803] __pci_register_driver+0x77/0x80
[ 2.782803] ? myrb_init_module+0x62/0x62
[ 2.782803] myrs_init_module+0x41/0x62
[ 2.782803] do_one_initcall+0x7a/0x3d0
[ 2.782803] ? rdinit_setup+0x40/0x40
[ 2.782803] ? rcu_read_lock_sched_held+0x4a/0x70
[ 2.782803] kernel_init_freeable+0x2a7/0x2f9
[ 2.782803] ? rest_init+0x2c0/0x2c0
[ 2.782803] kernel_init+0x13/0x180
[ 2.782803] ? rest_init+0x2c0/0x2c0
[ 2.782803] ? rest_init+0x2c0/0x2c0
[ 2.782803] ret_from_fork+0x1f/0x30
[ 2.782803] Modules linked in:
[ 2.782803] Dumping ftrace buffer:
[ 2.782803] (ftrace buffer empty)
[ 2.782803] CR2: 0000000000000000
[ 2.782803] ---[ end trace c5cb7be94bce994d ]---
[ 2.782803] RIP: 0010:0x0
[ 2.782803] Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
[ 2.782803] RSP: 0000:ffffc90000017b60 EFLAGS: 00010293
[ 2.782803] RAX: ffff8881001e0000 RBX: ffff888107a7cdb0 RCX: 0000000000000000
[ 2.782803] RDX: 0000000000000000 RSI: ffffffff824409c6 RDI: ffff888107a7cdb0
[ 2.782803] RBP: ffffc90000017b80 R08: 0000000000000001 R09: 0000000000000001
[ 2.782803] R10: 0000000000000000 R11: 0000000000000001 R12: ffff888101c34000
[ 2.782803] R13: ffff888007840000 R14: ffffc90000091000 R15: ffffffff82443300
[ 2.782803] FS: 0000000000000000(0000) GS:ffff88817bcc0000(0000) knlGS:0000000000000000
[ 2.782803] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 2.782803] CR2: ffffffffffffffd6 CR3: 0000000005e2e000 CR4: 00000000000006e0
[ 2.782803] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 2.782803] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 2.782803] Kernel panic - not syncing: Fatal exception
[ 2.782803] Dumping ftrace buffer:
[ 2.782803] (ftrace buffer empty)
[ 2.782803] Kernel Offset: disabled
[ 2.782803] Rebooting in 1 seconds..
Signed-off-by: Zheyu Ma <zheyuma97@xxxxxxxxx>
---
drivers/scsi/myrs.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/scsi/myrs.c b/drivers/scsi/myrs.c
index 3b68c68d1716..875ef60ebdd0 100644
--- a/drivers/scsi/myrs.c
+++ b/drivers/scsi/myrs.c
@@ -2268,8 +2268,10 @@ static void myrs_cleanup(struct myrs_hba *cs)
/* Free the memory mailbox, status, and related structures */
myrs_unmap(cs);
- if (cs->mmio_base) {
+ if (cs->disable_intr)
cs->disable_intr(cs);
+
+ if (cs->mmio_base) {
iounmap(cs->mmio_base);
cs->mmio_base = NULL;
}
--
2.17.6