> UBSAN: Undefined behaviour in ../drivers/vhost/vhost.c:52:1
> member access within null pointer of type 'struct rb_root'
> CPU: 2 PID: 1450 Comm: syz-executor493 Not tainted
> 4.12.14-525.g4d6309b-default #1 SLE15 (unreleased)
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
> 1.0.0-prebuilt.qemu-project.org 04/01/2014
> Call Trace:
> __dump_stack lib/dump_stack.c:16 [inline]
> dump_stack+0xc6/0x159 lib/dump_stack.c:52
> ubsan_epilogue+0xe/0x81 lib/ubsan.c:164
> handle_missaligned_access lib/ubsan.c:299 [inline]
> __ubsan_handle_type_mismatch+0x2ed/0x44e lib/ubsan.c:325
> vhost_chr_write_iter+0x103e/0x1330 [vhost]
> call_write_iter include/linux/fs.h:1764 [inline]
> new_sync_write fs/read_write.c:497 [inline]
> __vfs_write+0x67c/0x9b0 fs/read_write.c:510
> vfs_write+0x1a2/0x610 fs/read_write.c:558
> SYSC_write fs/read_write.c:605 [inline]
> SyS_write+0xd8/0x1f0 fs/read_write.c:597
> do_syscall_64+0x26b/0x6e0 arch/x86/entry/common.c:284
> entry_SYSCALL_64_after_hwframe+0x3d/0xa2
> RIP: 0033:0x7fdb7687a739
> RSP: 002b:00007ffd48719f38 EFLAGS: 00000213 ORIG_RAX: 0000000000000001
> RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fdb7687a739
> RDX: 0000000000000068 RSI: 0000000020000300 RDI: 0000000000000003
> RBP: 00000000004006f0 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000213 R12: 00000000004004a0
> R13: 00007ffd4871a020 R14: 0000000000000000 R15: 0000000000000000
> ================================================================================
> kasan: CONFIG_KASAN_INLINE enabled
> kasan: GPF could be caused by NULL-ptr deref or user memory access
> general protection fault: 0000 [#1] SMP KASAN PTI
> Modules linked in: vhost_net tun vhost tap af_packet iscsi_ibft
> iscsi_boot_sysfs bochs_drm ttm ppdev drm_kms_helper drm
> drm_panel_orientation_quirks joydev e1000 syscopyarea sysfillrect
> pcspkr sysimgblt fb_sys_fops i2c_piix4 parport_pc parport qemu_fw_cfg
> button ext4 crc16 jbd2 mbcache sr_mod cdrom sd_mod ata_generic
> ata_piix ahci libahci libata serio_raw floppy sg dm_multipath dm_mod
> scsi_dh_rdac scsi_dh_emc scsi_dh_alua scsi_mod autofs4
> Supported: No, Unreleased kernel
> CPU: 2 PID: 1450 Comm: syz-executor493 Not tainted
> 4.12.14-525.g4d6309b-default #1 SLE15 (unreleased)
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS
> 1.0.0-prebuilt.qemu-project.org 04/01/2014
> task: ffff88004b858040 task.stack: ffff88004a820000
> RIP: 0010:vhost_chr_write_iter+0x525/0x1330 [vhost]
> RSP: 0018:ffff88004a827a38 EFLAGS: 00010246
> RAX: dffffc0000000000 RBX: 1ffff10009504f51 RCX: 0000000000000000
> RDX: 0000000000000000 RSI: 0000000000000202 RDI: ffffed0009504f40
> RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
> R10: 1ffff10009504ec1 R11: 0000000000000000 R12: 0000000020000040
> R13: dffffc0000000000 R14: ffff8800352f0000 R15: ffffed0006a5e005
> FS: 00007fdb76f79740(0000) GS:ffff880060d00000(0000)
> knlGS:0000000000000000
> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000055b42161d980 CR3: 000000003422c000 CR4: 00000000000006e0
> Call Trace:
> call_write_iter include/linux/fs.h:1764 [inline]
> new_sync_write fs/read_write.c:497 [inline]
> __vfs_write+0x67c/0x9b0 fs/read_write.c:510
> vfs_write+0x1a2/0x610 fs/read_write.c:558
> SYSC_write fs/read_write.c:605 [inline]
> SyS_write+0xd8/0x1f0 fs/read_write.c:597
> do_syscall_64+0x26b/0x6e0 arch/x86/entry/common.c:284
> entry_SYSCALL_64_after_hwframe+0x3d/0xa2
> RIP: 0033:0x7fdb7687a739
> RSP: 002b:00007ffd48719f38 EFLAGS: 00000213 ORIG_RAX: 0000000000000001
> RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fdb7687a739
> RDX: 0000000000000068 RSI: 0000000020000300 RDI: 0000000000000003
> RBP: 00000000004006f0 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000213 R12: 00000000004004a0
> R13: 00007ffd4871a020 R14: 0000000000000000 R15: 0000000000000000
> Code: fc ff df 80 3c 02 00 0f 85 3c 0b 00 00 49 8b 6e 60 48 85 ed 0f
> 84 1c 0b 00 00 48 89 ea 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 <80>
> 3c 02 00 0f 85 f4 0a 00 00 4c 8b 7d 00 4d 85 ff 0f 84 e7 06
> RIP: vhost_chr_write_iter+0x525/0x1330 [vhost] RSP: ffff88004a827a38
> ---[ end trace 49849730b5255f76 ]---
Fixes: 6b1e6cc7855b ("vhost: new device IOTLB API")
Signed-off-by: Denis Kirjanov <kda@xxxxxxxxxxxxxxxxx>
---
drivers/vhost/vhost.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index e995c12d8e24..026123a6fc7b 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -962,7 +962,8 @@ static void vhost_del_umem_range(struct vhost_umem *umem,
while ((node = vhost_umem_interval_tree_iter_first(&umem->umem_tree,
start, end)))
- vhost_umem_free(umem, node);
+ if (node)
+ vhost_umem_free(umem, node);
}
static void vhost_iotlb_notify_vq(struct vhost_dev *d,
--
2.12.3
