aboutsummaryrefslogtreecommitdiff
path: root/drivers/target
diff options
context:
space:
mode:
authorNicholas Bellinger <nab@linux-iscsi.org>2011-02-09 15:34:38 -0800
committerJames Bottomley <James.Bottomley@suse.de>2011-02-12 11:37:00 -0600
commitbc66552476d3faf706ea72f5a082df717ed6c30d (patch)
tree52fc15a6907c502bfd7b701bc70265c2d24bc734 /drivers/target
parent3ae279d25954de47c704ca713a2711ac10fcd1ee (diff)
downloadlinux-2.6.38-lt-ux500-bc66552476d3faf706ea72f5a082df717ed6c30d.tar.gz
[SCSI] target/iblock: Fix failed bd claim NULL pointer dereference
This patch adds an explict check for struct iblock_dev->ibd_bd in iblock_free_device() before calling blkdev_put(), which will otherwise hit the following NULL pointer dereference @ ib_dev->ibd_bd when iblock_create_virtdevice() fails to claim an already in-use struct block_device via blkdev_get_by_path(). [ 112.528578] Target_Core_ConfigFS: Allocated struct se_subsystem_dev: ffff88001e750000 se_dev_su_ptr: ffff88001dd05d70 [ 112.534681] Target_Core_ConfigFS: Calling t->free_device() for se_dev_su_ptr: ffff88001dd05d70 [ 112.535029] BUG: unable to handle kernel NULL pointer dereference at 0000000000000020 [ 112.535029] IP: [<ffffffff814987a3>] mutex_lock+0x14/0x35 [ 112.535029] PGD 1e5d0067 PUD 1e274067 PMD 0 [ 112.535029] Oops: 0002 [#1] SMP [ 112.535029] last sysfs file: /sys/devices/pci0000:00/0000:00:07.1/host2/target2:0:0/2:0:0:0/type [ 112.535029] CPU 0 [ 112.535029] Modules linked in: iscsi_target_mod target_core_stgt scsi_tgt target_core_pscsi target_core_file target_core_iblock target_core_mod configfs sr_mod cdrom sd_mod ata_piix mptspi mptscsih libata mptbase [last unloaded: scsi_wait_scan] [ 112.535029] [ 112.535029] Pid: 3345, comm: python2.5 Not tainted 2.6.37+ #1 440BX Desktop Reference Platform/VMware Virtual Platform [ 112.535029] RIP: 0010:[<ffffffff814987a3>] [<ffffffff814987a3>] mutex_lock+0x14/0x35 [ 112.535029] RSP: 0018:ffff88001e6d7d58 EFLAGS: 00010246 [ 112.535029] RAX: 0000000000000000 RBX: 0000000000000020 RCX: 0000000000000082 [ 112.535029] RDX: ffff88001e6d7fd8 RSI: 0000000000000083 RDI: 0000000000000020 [ 112.535029] RBP: ffff88001e6d7d68 R08: 0000000000000000 R09: 0000000000000000 [ 112.535029] R10: ffff8800000be860 R11: ffff88001f420000 R12: 0000000000000020 [ 112.535029] R13: 0000000000000083 R14: ffff88001d809430 R15: ffff88001d8094f8 [ 112.535029] FS: 00007ff17ca7d6e0(0000) GS:ffff88001fa00000(0000) knlGS:0000000000000000 [ 112.535029] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 112.535029] CR2: 0000000000000020 CR3: 000000001e5d2000 CR4: 00000000000006f0 [ 112.535029] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 112.535029] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 [ 112.535029] Process python2.5 (pid: 3345, threadinfo ffff88001e6d6000, task ffff88001e2d0760) [ 112.535029] Stack: [ 112.535029] ffff88001e6d7d88 0000000000000000 ffff88001e6d7d98 ffffffff811187fc [ 112.535029] ffff88001d809430 ffff88001dd05d70 ffff88001e750860 ffff88001e750000 [ 112.535029] ffff88001e6d7db8 ffffffffa00e3757 ffff88001e6d7db8 0000000000000004 [ 112.535029] Call Trace: [ 112.535029] [<ffffffff811187fc>] blkdev_put+0x28/0x107 [ 112.535029] [<ffffffffa00e3757>] iblock_free_device+0x1d/0x36 [target_core_iblock] [ 112.535029] [<ffffffffa00a319c>] target_core_drop_subdev+0x15f/0x18d [target_core_mod] [ 112.535029] [<ffffffffa00960db>] client_drop_item+0x25/0x31 [configfs] [ 112.535029] [<ffffffffa00967b5>] configfs_rmdir+0x1a1/0x223 [configfs] [ 112.535029] [<ffffffff810fa8cd>] vfs_rmdir+0x7e/0xd3 [ 112.535029] [<ffffffff810fc3be>] do_rmdir+0xa3/0xf4 [ 112.535029] [<ffffffff810fc446>] sys_rmdir+0x11/0x13 [ 112.535029] [<ffffffff81002a92>] system_call_fastpath+0x16/0x1b [ 112.535029] Code: 8b 04 25 88 b5 00 00 48 2d d8 1f 00 00 48 89 43 18 31 c0 5e 5b c9 c3 55 48 89 e5 53 48 89 fb 48 83 ec 08 e8 c4 f7 ff ff 48 89 df <3e> ff 0f 79 05 e8 1e ff ff ff 65 48 8b 04 25 88 b5 00 00 48 2d [ 112.535029] RIP [<ffffffff814987a3>] mutex_lock+0x14/0x35 [ 112.535029] RSP <ffff88001e6d7d58> [ 112.535029] CR2: 0000000000000020 [ 132.679636] ---[ end trace 05754bb48eb828f0 ]--- Note it also adds an second explict check for ib_dev->ibd_bio_set before calling bioset_free() to fix the same possible NULL pointer deference during an early iblock_create_virtdevice() failure. Signed-off-by: Nicholas A. Bellinger <nab@linux-iscsi.org> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Diffstat (limited to 'drivers/target')
-rw-r--r--drivers/target/target_core_iblock.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/target/target_core_iblock.c b/drivers/target/target_core_iblock.c
index 34561350d5e..67f0c09983c 100644
--- a/drivers/target/target_core_iblock.c
+++ b/drivers/target/target_core_iblock.c
@@ -220,8 +220,10 @@ static void iblock_free_device(void *p)
{
struct iblock_dev *ib_dev = p;
- blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
- bioset_free(ib_dev->ibd_bio_set);
+ if (ib_dev->ibd_bd != NULL)
+ blkdev_put(ib_dev->ibd_bd, FMODE_WRITE|FMODE_READ|FMODE_EXCL);
+ if (ib_dev->ibd_bio_set != NULL)
+ bioset_free(ib_dev->ibd_bio_set);
kfree(ib_dev);
}