kernel/linux.git/block, branch v3.0.22

block: fail SCSI passthrough ioctls on partition devices

2012-01-26T01:24:54+00:00

commit 0bfc96cb77224736dfa35c3c555d37b3646ef35e upstream. [ Changes with respect to 3.3: return -ENOTTY from scsi_verify_blk_ioctl and -ENOIOCTLCMD from sd_compat_ioctl. ] Linux allows executing the SG_IO ioctl on a partition or LVM volume, and will pass the command to the underlying block device. This is well-known, but it is also a large security problem when (via Unix permissions, ACLs, SELinux or a combination thereof) a program or user needs to be granted access only to part of the disk. This patch lets partitions forward a small set of harmless ioctls; others are logged with printk so that we can see which ioctls are actually sent. In my tests only CDROM_GET_CAPABILITY actually occurred. Of course it was being sent to a (partition on a) hard disk, so it would have failed with ENOTTY and the patch isn't changing anything in practice. Still, I'm treating it specially to avoid spamming the logs. In principle, this restriction should include programs running with CAP_SYS_RAWIO. If for example I let a program access /dev/sda2 and /dev/sdb, it still should not be able to read/write outside the boundaries of /dev/sda2 independent of the capabilities. However, for now programs with CAP_SYS_RAWIO will still be allowed to send the ioctls. Their actions will still be logged. This patch does not affect the non-libata IDE driver. That driver however already tests for bd != bd->bd_contains before issuing some ioctl; it could be restricted further to forbid these ioctls even for programs running with CAP_SYS_ADMIN/CAP_SYS_RAWIO. Cc: linux-scsi@vger.kernel.org Cc: Jens Axboe Cc: James Bottomley Signed-off-by: Paolo Bonzini [ Make it also print the command name when warning - Linus ] Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

block: add and use scsi_blk_cmd_ioctl

2012-01-26T01:24:54+00:00

commit 577ebb374c78314ac4617242f509e2f5e7156649 upstream. Introduce a wrapper around scsi_cmd_ioctl that takes a block device. The function will then be enhanced to detect partition block devices and, in that case, subject the ioctls to whitelisting. Cc: linux-scsi@vger.kernel.org Cc: Jens Axboe Cc: James Bottomley Signed-off-by: Paolo Bonzini Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

block: initialize request_queue's numa node during

2012-01-06T22:13:48+00:00

commit 5151412dd4338b273afdb107c3772528e9e67d92 upstream. struct request_queue is allocated with __GFP_ZERO so its "node" field is zero before initialization. This causes an oops if node 0 is offline in the page allocator because its zonelists are not initialized. From Dave Young's dmesg: SRAT: Node 1 PXM 2 0-d0000000 SRAT: Node 1 PXM 2 100000000-330000000 SRAT: Node 0 PXM 1 330000000-630000000 Initmem setup node 1 0000000000000000-000000000affb000 ... Built 1 zonelists in Node order, mobility grouping on. ... BUG: unable to handle kernel paging request at 0000000000001c08 IP: [] __alloc_pages_nodemask+0xb5/0x870 and __alloc_pages_nodemask+0xb5 translates to a NULL pointer on zonelist->_zonerefs. The fix is to initialize q->node at the time of allocation so the correct node is passed to the slab allocator later. Since blk_init_allocated_queue_node() is no longer needed, merge it with blk_init_allocated_queue(). [rientjes@google.com: changelog, initializing q->node] Reported-by: Dave Young Signed-off-by: Mike Snitzer Signed-off-by: David Rientjes Tested-by: Dave Young Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

cfq-iosched: fix cfq_cic_link() race confition

2012-01-06T22:13:46+00:00

commit 5eb46851de3904cd1be9192fdacb8d34deadc1fc upstream. cfq_cic_link() has race condition. When some processes which shared ioc issue I/O to same block device simultaneously, cfq_cic_link() returns -EEXIST sometimes. The race condition might stop I/O by following steps: step 1: Process A: Issue an I/O to /dev/sda step 2: Process A: Get an ioc (iocA here) in get_io_context() which does not linked with a cic for the device step 3: Process A: Get a new cic for the device (cicA here) in cfq_alloc_io_context() step 4: Process B: Issue an I/O to /dev/sda step 5: Process B: Get iocA in get_io_context() since process A and B share the same ioc step 6: Process B: Get a new cic for the device (cicB here) in cfq_alloc_io_context() since iocA has not been linked with a cic for the device yet step 7: Process A: Link cicA to iocA in cfq_cic_link() step 8: Process A: Dispatch I/O to driver and finish it step 9: Process B: Try to link cicB to iocA in cfq_cic_link() But it fails with showing "cfq: cic link failed!" kernel message, since iocA has already linked with cicA at step 7. step 10: Process B: Wait for finishig I/O in get_request_wait() The function does not wake up, when there is no I/O to the device. When cfq_cic_link() returns -EEXIST, it means ioc has already linked with cic. So when cfq_cic_link() return -EEXIST, retry cfq_cic_lookup(). Signed-off-by: Yasuaki Ishimatsu Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

cfq-iosched: free cic_index if blkio_alloc_blkg_stats fails

2012-01-06T22:13:46+00:00

commit 2984ff38ccf6cbc02a7a996a36c7d6f69f3c6146 upstream. If we fail allocating the blkpg stats, we free cfqd and cfgq. But we need to free the IDA cfqd->cic_index as well. Signed-off-by: majianpeng Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

block: Always check length of all iov entries in blk_rq_map_user_iov()

2011-11-21T22:31:26+00:00

commit 6b76106d8ef31111d6fc469564b83b5f5542794f upstream. Even after commit 5478755616ae2ef1ce144dded589b62b2a50d575 ("block: check for proper length of iov entries earlier ...") we still won't check for zero-length entries after an unaligned entry. Remove the break-statement, so all entries are checked. Signed-off-by: Ben Hutchings Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

block: make gendisk hold a reference to its queue

2011-11-11T17:37:07+00:00

commit f992ae801a7dec34a4ed99a6598bbbbfb82af4fb upstream. The following command sequence triggers an oops. # mount /dev/sdb1 /mnt # echo 1 > /sys/class/scsi_device/0\:0\:1\:0/device/delete # umount /mnt general protection fault: 0000 [#1] PREEMPT SMP CPU 2 Modules linked in: Pid: 791, comm: umount Not tainted 3.1.0-rc3-work+ #8 Bochs Bochs RIP: 0010:[] [] __lock_acquire+0x389/0x1d60 ... Call Trace: [] lock_acquire+0x95/0x140 [] _raw_spin_lock+0x3b/0x50 [] bdi_lock_two+0x5c/0x70 [] bdev_inode_switch_bdi+0x4c/0xf0 [] __blkdev_put+0x11b/0x1d0 [] __blkdev_put+0x160/0x1d0 [] blkdev_put+0x5f/0x190 [] kill_block_super+0x4d/0x80 [] deactivate_locked_super+0x45/0x70 [] deactivate_super+0x4a/0x70 [] mntput_no_expire+0xed/0x130 [] sys_umount+0x7e/0x3a0 [] system_call_fastpath+0x16/0x1b This is because bdev holds on to disk but disk doesn't pin the associated queue. If a SCSI device is removed while the device is still open, the sdev puts the base reference to the queue on release. When the bdev is finally released, the associated queue is already gone along with the bdi and bdev_inode_switch_bdi() ends up dereferencing already freed bdi. Even if it were not for this bug, disk not holding onto the associated queue is very unusual and error-prone. Fix it by making add_disk() take an extra reference to its queue and put it on disk_release() and ensuring that disk and its fops owner are put in that order after all accesses to the disk and queue are complete. Signed-off-by: Tejun Heo Cc: Jens Axboe Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

block: Free queue resources at blk_release_queue()

2011-10-03T18:41:13+00:00

commit 777eb1bf15b8532c396821774bf6451e563438f5 upstream. A kernel crash is observed when a mounted ext3/ext4 filesystem is physically removed. The problem is that blk_cleanup_queue() frees up some resources eg by calling elevator_exit(), which are not checked for in normal operation. So we should rather move these calls to the destructor function blk_release_queue() as at that point all remaining references are gone. However, in doing so we have to ensure that any externally supplied queue_lock is disconnected as the driver might free up the lock after the call of blk_cleanup_queue(), Signed-off-by: Hannes Reinecke Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

blk-cgroup: be able to remove the record of unplugged device

2011-10-03T18:40:42+00:00

commit d11bb4462c4cc6ddd45c6927c617ad79fa6fb8fc upstream. The bug is we're not able to remove the device from blkio cgroup's per-device control files if it gets unplugged. To reproduce the bug: # mount -t cgroup -o blkio xxx /cgroup # cd /cgroup # echo "8:0 1000" > blkio.throttle.read_bps_device # unplug the device # cat blkio.throttle.read_bps_device 8:0 1000 # echo "8:0 0" > blkio.throttle.read_bps_device -bash: echo: write error: No such device After patching, the device removal will succeed. Thanks for the comments of Paul, Zefan, and Vivek. Signed-off-by: Wanlong Gao Cc: Li Zefan Cc: Paul Menage Acked-by: Vivek Goyal Cc: Jens Axboe Signed-off-by: Andrew Morton Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

fix crash in scsi_dispatch_cmd()

2011-08-05T04:58:36+00:00

commit bfe159a51203c15d23cb3158fffdc25ec4b4dda1 upstream. USB surprise removal of sr is triggering an oops in scsi_dispatch_command(). What seems to be happening is that USB is hanging on to a queue reference until the last close of the upper device, so the crash is caused by surprise remove of a mounted CD followed by attempted unmount. The problem is that USB doesn't issue its final commands as part of the SCSI teardown path, but on last close when the block queue is long gone. The long term fix is probably to make sr do the teardown in the same way as sd (so remove all the lower bits on ejection, but keep the upper disk alive until last close of user space). However, the current oops can be simply fixed by not allowing any commands to be sent to a dead queue. Signed-off-by: James Bottomley Signed-off-by: Greg Kroah-Hartman