On Fri, Apr 11, 2014 at 03:23:45PM +0800, Fam Zheng wrote: > virtscsi_init calls virtscsi_remove_vqs on err, even before initializing > the vqs. The latter calls virtscsi_set_affinity, so let's check the > pointer there before setting affinity on it. > > This fixes a panic when setting device's num_queues=2 on RHEL 6.5: > > qemu-system-x86_64 ... \ > -device virtio-scsi-pci,id=scsi0,addr=0x13,...,num_queues=2 \ > -drive file=/stor/vm/dummy.raw,id=drive-scsi-disk,... \ > -device scsi-hd,drive=drive-scsi-disk,... > > [ 0.354734] scsi0 : Virtio SCSI HBA > [ 0.379504] BUG: unable to handle kernel NULL pointer dereference at 0000000000000020 > [ 0.380141] IP: [<ffffffff814741ef>] __virtscsi_set_affinity+0x4f/0x120 > [ 0.380141] PGD 0 > [ 0.380141] Oops: 0000 [#1] SMP > [ 0.380141] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 3.14.0+ #5 > [ 0.380141] Hardware name: Red Hat KVM, BIOS 0.5.1 01/01/2007 > [ 0.380141] task: ffff88003c9f0000 ti: ffff88003c9f8000 task.ti: ffff88003c9f8000 > [ 0.380141] RIP: 0010:[<ffffffff814741ef>] [<ffffffff814741ef>] __virtscsi_set_affinity+0x4f/0x120 > [ 0.380141] RSP: 0000:ffff88003c9f9c08 EFLAGS: 00010256 > [ 0.380141] RAX: 0000000000000000 RBX: ffff88003c3a9d40 RCX: 0000000000001070 > [ 0.380141] RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000 > [ 0.380141] RBP: ffff88003c9f9c28 R08: 00000000000136c0 R09: ffff88003c801c00 > [ 0.380141] R10: ffffffff81475229 R11: 0000000000000008 R12: 0000000000000000 > [ 0.380141] R13: ffffffff81cc7ca8 R14: ffff88003cac3d40 R15: ffff88003cac37a0 > [ 0.380141] FS: 0000000000000000(0000) GS:ffff88003e400000(0000) knlGS:0000000000000000 > [ 0.380141] CS: 0010 DS: 0000 ES: 0000 CR0: 000000008005003b > [ 0.380141] CR2: 0000000000000020 CR3: 0000000001c0e000 CR4: 00000000000006f0 > [ 0.380141] Stack: > [ 0.380141] ffff88003c3a9d40 0000000000000000 ffff88003cac3d80 ffff88003cac3d40 > [ 0.380141] ffff88003c9f9c48 ffffffff814742e8 ffff88003c26d000 ffff88003c26d000 > [ 0.380141] ffff88003c9f9c68 ffffffff81474321 ffff88003c26d000 ffff88003c3a9d40 > [ 0.380141] Call Trace: > [ 0.380141] [<ffffffff814742e8>] virtscsi_set_affinity+0x28/0x40 > [ 0.380141] [<ffffffff81474321>] virtscsi_remove_vqs+0x21/0x50 > [ 0.380141] [<ffffffff81475231>] virtscsi_init+0x91/0x240 > [ 0.380141] [<ffffffff81365290>] ? vp_get+0x50/0x70 > [ 0.380141] [<ffffffff81475544>] virtscsi_probe+0xf4/0x280 > [ 0.380141] [<ffffffff81363ea5>] virtio_dev_probe+0xe5/0x140 > [ 0.380141] [<ffffffff8144c669>] driver_probe_device+0x89/0x230 > [ 0.380141] [<ffffffff8144c8ab>] __driver_attach+0x9b/0xa0 > [ 0.380141] [<ffffffff8144c810>] ? driver_probe_device+0x230/0x230 > [ 0.380141] [<ffffffff8144c810>] ? driver_probe_device+0x230/0x230 > [ 0.380141] [<ffffffff8144ac1c>] bus_for_each_dev+0x8c/0xb0 > [ 0.380141] [<ffffffff8144c499>] driver_attach+0x19/0x20 > [ 0.380141] [<ffffffff8144bf28>] bus_add_driver+0x198/0x220 > [ 0.380141] [<ffffffff8144ce9f>] driver_register+0x5f/0xf0 > [ 0.380141] [<ffffffff81d27c91>] ? spi_transport_init+0x79/0x79 > [ 0.380141] [<ffffffff8136403b>] register_virtio_driver+0x1b/0x30 > [ 0.380141] [<ffffffff81d27d19>] init+0x88/0xd6 > [ 0.380141] [<ffffffff81d27c18>] ? scsi_init_procfs+0x5b/0x5b > [ 0.380141] [<ffffffff81ce88a7>] do_one_initcall+0x7f/0x10a > [ 0.380141] [<ffffffff81ce8aa7>] kernel_init_freeable+0x14a/0x1de > [ 0.380141] [<ffffffff81ce8b3b>] ? kernel_init_freeable+0x1de/0x1de > [ 0.380141] [<ffffffff817dec20>] ? rest_init+0x80/0x80 > [ 0.380141] [<ffffffff817dec29>] kernel_init+0x9/0xf0 > [ 0.380141] [<ffffffff817e68fc>] ret_from_fork+0x7c/0xb0 > [ 0.380141] [<ffffffff817dec20>] ? rest_init+0x80/0x80 > [ 0.380141] RIP [<ffffffff814741ef>] __virtscsi_set_affinity+0x4f/0x120 > [ 0.380141] RSP <ffff88003c9f9c08> > [ 0.380141] CR2: 0000000000000020 > [ 0.380141] ---[ end trace 8074b70c3d5e1d73 ]--- > [ 0.475018] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 > [ 0.475018] > [ 0.475068] Kernel Offset: 0x0 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffff9fffffff) > [ 0.475068] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000009 > > Signed-off-by: Fam Zheng <famz@xxxxxxxxxx> > --- > drivers/scsi/virtio_scsi.c | 6 +++++- > 1 file changed, 5 insertions(+), 1 deletion(-) <formletter> This is not the correct way to submit patches for inclusion in the stable kernel tree. Please read Documentation/stable_kernel_rules.txt for how to do this properly. </formletter> -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html