Inject fault while probing mdpy.ko, if kstrdup() fails in
kobject_set_name_varg() in dev_set_name(), the strchr()
in kobject_add() of device_add() will cause null-ptr-deref below.
So check the err of dev_set_name().
[ 108.095977] general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
[ 108.097756] KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
[ 108.098983] CPU: 1 PID: 8948 Comm: modprobe Not tainted 6.5.0-g32bf43e4efdb #50
[ 108.100455] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1.1 04/01/2014
[ 108.102384] RIP: 0010:strchr+0x17/0xa0
[ 108.103156] Code: 48 89 34 24 e8 fa 59 ad fd 48 8b 34 24 eb 9a 0f 1f 40 00 48 b8 00 00 00 00 00 fc ff df 55 48 89 fa 53 48 c1 ea 03 48 83 ec 10 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 04 84 c0 75 51 0f b6 07 89
[ 108.106140] RSP: 0018:ffff88811035f6a0 EFLAGS: 00010286
[ 108.107012] RAX: dffffc0000000000 RBX: ffffffffa02696e0 RCX: 1ffffffff404d2dc
[ 108.108177] RDX: 0000000000000000 RSI: 0000000000000025 RDI: 0000000000000000
[ 108.109336] RBP: 0000000000000000 R08: ffff88810021eb28 R09: ffff8881055b6a28
[ 108.110498] R10: ffffed1020d5f1ca R11: ffff888106af8e53 R12: ffff88811035f748
[ 108.111663] R13: 0000000000000cc0 R14: ffff8881055b6a28 R15: ffffffffa02696e0
[ 108.112865] FS: 00007f0264601540(0000) GS:ffff88811a080000(0000) knlGS:0000000000000000
[ 108.114493] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 108.115685] CR2: 00007fff2f084578 CR3: 000000010b50a003 CR4: 0000000000170ee0
[ 108.117127] Call Trace:
[ 108.117681] <TASK>
[ 108.118087] ? __die_body+0x1b/0x60
[ 108.118810] ? die_addr+0x43/0x70
[ 108.119558] ? exc_general_protection+0x121/0x210
[ 108.120634] ? asm_exc_general_protection+0x22/0x30
[ 108.121748] ? strchr+0x17/0xa0
[ 108.122411] kvasprintf_const+0x1c/0x120
[ 108.123237] kobject_set_name_vargs+0x41/0x110
[ 108.124169] ? kobject_add_internal+0x860/0x860
[ 108.125169] ? kasan_unpoison+0x23/0x50
[ 108.125994] kobject_add+0xec/0x1f0
[ 108.126741] ? _raw_spin_unlock_irqrestore+0x42/0x80
[ 108.127847] ? kobject_add_internal+0x860/0x860
[ 108.128786] ? mutex_unlock+0x80/0xd0
[ 108.129629] ? kobject_put+0x5c/0x310
[ 108.130410] ? get_device_parent.isra.0+0x1a2/0x430
[ 108.131517] ? kobject_put+0x5c/0x310
[ 108.132281] device_add+0x2ca/0x1440
[ 108.133039] ? __fw_devlink_link_to_suppliers+0x180/0x180
[ 108.134198] ? __hrtimer_init+0x38/0x200
[ 108.135080] ? pm_runtime_init+0x2df/0x3d0
[ 108.136050] mdpy_dev_init+0xfb/0x1000 [mdpy]
[ 108.136974] ? 0xffffffffa0298000
[ 108.137680] do_one_initcall+0x87/0x2e0
[ 108.138600] ? efi_enabled.constprop.0+0x50/0x50
[ 108.139591] ? _raw_spin_unlock_irqrestore+0x42/0x80
[ 108.140646] ? __kmem_cache_alloc_node+0x342/0x550
[ 108.141626] ? do_init_module+0x4b/0x750
[ 108.142552] ? kasan_unpoison+0x23/0x50
[ 108.143350] do_init_module+0x24d/0x750
[ 108.144163] load_module+0x4e60/0x68d0
[ 108.145060] ? module_frob_arch_sections+0x20/0x20
[ 108.146028] ? update_cfs_group+0x10c/0x2a0
[ 108.146926] ? __wake_up_common+0x10b/0x5d0
[ 108.147807] ? kernel_read_file+0x3ca/0x510
[ 108.148680] ? __x64_sys_fsconfig+0x650/0x650
[ 108.149621] ? __schedule+0xa0b/0x2a60
[ 108.150424] ? init_module_from_file+0xd2/0x130
[ 108.151452] init_module_from_file+0xd2/0x130
[ 108.152360] ? __ia32_sys_init_module+0xa0/0xa0
[ 108.153360] ? _raw_spin_lock_irqsave+0xe0/0xe0
[ 108.154289] ? ptrace_stop+0x487/0x790
[ 108.155123] idempotent_init_module+0x32d/0x6a0
[ 108.156045] ? init_module_from_file+0x130/0x130
[ 108.156999] ? __fget_light+0x57/0x500
[ 108.157809] __x64_sys_finit_module+0xbb/0x130
[ 108.158744] do_syscall_64+0x35/0x80
[ 108.159547] entry_SYSCALL_64_after_hwframe+0x46/0xb0
[ 108.160601] RIP: 0033:0x7f0263f1b839
[ 108.161337] Code: 00 f3 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 1f f6 2c 00 f7 d8 64 89 01 48
[ 108.165113] RSP: 002b:00007fff2f087658 EFLAGS: 00000246 ORIG_RAX: 0000000000000139
[ 108.166645] RAX: ffffffffffffffda RBX: 000055d2140cddc0 RCX: 00007f0263f1b839
[ 108.168184] RDX: 0000000000000000 RSI: 000055d21321bc2e RDI: 0000000000000003
[ 108.169609] RBP: 000055d21321bc2e R08: 0000000000000000 R09: 000055d2140cddc0
[ 108.171054] R10: 0000000000000003 R11: 0000000000000246 R12: 0000000000000000
[ 108.172505] R13: 000055d2140cdf70 R14: 0000000000040000 R15: 000055d2140cddc0
[ 108.173986] </TASK>
[ 108.174480] Modules linked in: mdpy(+) mdev vfio_iommu_type1 vfio [last unloaded: mdpy]
[ 108.176116] Dumping ftrace buffer:
[ 108.176863] (ftrace buffer empty)
[ 108.177711] ---[ end trace 0000000000000000 ]---
[ 108.178837] RIP: 0010:strchr+0x17/0xa0
[ 108.179821] Code: 48 89 34 24 e8 fa 59 ad fd 48 8b 34 24 eb 9a 0f 1f 40 00 48 b8 00 00 00 00 00 fc ff df 55 48 89 fa 53 48 c1 ea 03 48 83 ec 10 <0f> b6 04 02 48 89 fa 83 e2 07 38 d0 7f 04 84 c0 75 51 0f b6 07 89
[ 108.183586] RSP: 0018:ffff88811035f6a0 EFLAGS: 00010286
[ 108.184680] RAX: dffffc0000000000 RBX: ffffffffa02696e0 RCX: 1ffffffff404d2dc
[ 108.186200] RDX: 0000000000000000 RSI: 0000000000000025 RDI: 0000000000000000
[ 108.187735] RBP: 0000000000000000 R08: ffff88810021eb28 R09: ffff8881055b6a28
[ 108.189175] R10: ffffed1020d5f1ca R11: ffff888106af8e53 R12: ffff88811035f748
[ 108.190694] R13: 0000000000000cc0 R14: ffff8881055b6a28 R15: ffffffffa02696e0
[ 108.192270] FS: 00007f0264601540(0000) GS:ffff88811a080000(0000) knlGS:0000000000000000
[ 108.193968] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 108.195151] CR2: 00007fff2f084578 CR3: 000000010b50a003 CR4: 0000000000170ee0
[ 108.196658] Kernel panic - not syncing: Fatal exception
[ 108.197907] Dumping ftrace buffer:
[ 108.198488] (ftrace buffer empty)
[ 108.199105] Kernel Offset: disabled
[ 108.199691] Rebooting in 1 seconds..
Fixes: d61fc96f47fd ("sample: vfio mdev display - host device")
Signed-off-by: Jinjie Ruan <ruanjinjie@xxxxxxxxxx>
---
samples/vfio-mdev/mdpy.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/samples/vfio-mdev/mdpy.c b/samples/vfio-mdev/mdpy.c
index 064e1c0a7aa8..f6b79f1f0a67 100644
--- a/samples/vfio-mdev/mdpy.c
+++ b/samples/vfio-mdev/mdpy.c
@@ -717,7 +717,9 @@ static int __init mdpy_dev_init(void)
}
mdpy_dev.class = mdpy_class;
mdpy_dev.release = mdpy_device_release;
- dev_set_name(&mdpy_dev, "%s", MDPY_NAME);
+ ret = dev_set_name(&mdpy_dev, "%s", MDPY_NAME);
+ if (ret)
+ goto err_put;
ret = device_register(&mdpy_dev);
if (ret)
--
2.34.1
