kernel/linux.git/block/genhd.c, branch v3.4.112

block: fix ext_dev_lock lockdep report

2015-09-18T01:20:46+00:00

commit 4d66e5e9b6d720d8463e11d027bd4ad91c8b1318 upstream. ================================= [ INFO: inconsistent lock state ] 4.1.0-rc7+ #217 Tainted: G O --------------------------------- inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. swapper/6/0 [HC0[0]:SC1[1]:HE1:SE0] takes: (ext_devt_lock){+.?...}, at: [] blk_free_devt+0x3c/0x70 {SOFTIRQ-ON-W} state was registered at: [] __lock_acquire+0x461/0x1e70 [] lock_acquire+0xb7/0x290 [] _raw_spin_lock+0x38/0x50 [] blk_alloc_devt+0x6d/0xd0 <-- take the lock in process context [..] [] __lock_acquire+0x3fe/0x1e70 [] ? __lock_acquire+0xe5d/0x1e70 [] lock_acquire+0xb7/0x290 [] ? blk_free_devt+0x3c/0x70 [] _raw_spin_lock+0x38/0x50 [] ? blk_free_devt+0x3c/0x70 [] blk_free_devt+0x3c/0x70 <-- take the lock in softirq [] part_release+0x1c/0x50 [] device_release+0x36/0xb0 [] kobject_cleanup+0x7b/0x1a0 [] kobject_put+0x30/0x70 [] put_device+0x17/0x20 [] delete_partition_rcu_cb+0x16c/0x180 [] ? read_dev_sector+0xa0/0xa0 [] rcu_process_callbacks+0x2ff/0xa90 [] ? rcu_process_callbacks+0x2bf/0xa90 [] __do_softirq+0xde/0x600 Neil sees this in his tests and it also triggers on pmem driver unbind for the libnvdimm tests. This fix is on top of an initial fix by Keith for incorrect usage of mutex_lock() in this path: 2da78092dda1 "block: Fix dev_t minor allocation lifetime". Both this and 2da78092dda1 are candidates for -stable. Fixes: 2da78092dda1 ("block: Fix dev_t minor allocation lifetime") Cc: Keith Busch Reported-by: NeilBrown Signed-off-by: Dan Williams Signed-off-by: Jens Axboe [lizf: Backported to 3.4: adjust context] Signed-off-by: Zefan Li

genhd: check for int overflow in disk_expand_part_tbl()

2015-04-14T09:33:42+00:00

commit 5fabcb4c33fe11c7e3afdf805fde26c1a54d0953 upstream. We can get here from blkdev_ioctl() -> blkpg_ioctl() -> add_partition() with a user passed in partno value. If we pass in 0x7fffffff, the new target in disk_expand_part_tbl() overflows the 'int' and we access beyond the end of ptbl->part[] and even write to it when we do the rcu_assign_pointer() to assign the new partition. Reported-by: David Ramos Signed-off-by: Jens Axboe Signed-off-by: Zefan Li

genhd: fix leftover might_sleep() in blk_free_devt()

2014-12-01T10:02:41+00:00

commit 46f341ffcfb5d8530f7d1e60f3be06cce6661b62 upstream. Commit 2da78092 changed the locking from a mutex to a spinlock, so we now longer sleep in this context. But there was a leftover might_sleep() in there, which now triggers since we do the final free from an RCU callback. Get rid of it. Reported-by: Pontus Fuchs Signed-off-by: Jens Axboe Signed-off-by: Zefan Li

block: Fix dev_t minor allocation lifetime

2014-12-01T10:02:26+00:00

commit 2da78092dda13f1efd26edbbf99a567776913750 upstream. Releases the dev_t minor when all references are closed to prevent another device from acquiring the same major/minor. Since the partition's release may be invoked from call_rcu's soft-irq context, the ext_dev_idr's mutex had to be replaced with a spinlock so as not so sleep. Signed-off-by: Keith Busch Signed-off-by: Jens Axboe [lizf: Backported to 3.4: - adjust context - remove idr_preload() and idr_preload_end()] Signed-off-by: Zefan Li

block: do not pass disk names as format strings

2013-07-13T18:03:41+00:00

commit ffc8b30866879ed9ba62bd0a86fecdbd51cd3d19 upstream. Disk names may contain arbitrary strings, so they must not be interpreted as format strings. It seems that only md allows arbitrary strings to be used for disk names, but this could allow for a local memory corruption from uid 0 into ring 0. CVE-2013-2851 Signed-off-by: Kees Cook Cc: Jens Axboe Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

block: fix synchronization and limit check in blk_alloc_devt()

2013-03-03T22:06:41+00:00

commit ce23bba842aee98092225d9576dba47c82352521 upstream. idr allocation in blk_alloc_devt() wasn't synchronized against lookup and removal, and its limit check was off by one - 1 << MINORBITS is the number of minors allowed, not the maximum allowed minor. Add locking and rename MAX_EXT_DEVT to NR_EXT_DEVT and fix limit checking. Signed-off-by: Tejun Heo Acked-by: Jens Axboe Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

block: fix ext_devt_idr handling

2013-03-03T22:06:40+00:00

commit 7b74e912785a11572da43292786ed07ada7e3e0c upstream. While adding and removing a lot of disks disks and partitions this sometimes shows up: WARNING: at fs/sysfs/dir.c:512 sysfs_add_one+0xc9/0x130() (Not tainted) Hardware name: sysfs: cannot create duplicate filename '/dev/block/259:751' Modules linked in: raid1 autofs4 bnx2fc cnic uio fcoe libfcoe libfc 8021q scsi_transport_fc scsi_tgt garp stp llc sunrpc cpufreq_ondemand powernow_k8 freq_table mperf ipv6 dm_mirror dm_region_hash dm_log power_meter microcode dcdbas serio_raw amd64_edac_mod edac_core edac_mce_amd i2c_piix4 i2c_core k10temp bnx2 sg ixgbe dca mdio ext4 mbcache jbd2 dm_round_robin sr_mod cdrom sd_mod crc_t10dif ata_generic pata_acpi pata_atiixp ahci mptsas mptscsih mptbase scsi_transport_sas dm_multipath dm_mod [last unloaded: scsi_wait_scan] Pid: 44103, comm: async/16 Not tainted 2.6.32-195.el6.x86_64 #1 Call Trace: warn_slowpath_common+0x87/0xc0 warn_slowpath_fmt+0x46/0x50 sysfs_add_one+0xc9/0x130 sysfs_do_create_link+0x12b/0x170 sysfs_create_link+0x13/0x20 device_add+0x317/0x650 idr_get_new+0x13/0x50 add_partition+0x21c/0x390 rescan_partitions+0x32b/0x470 sd_open+0x81/0x1f0 [sd_mod] __blkdev_get+0x1b6/0x3c0 blkdev_get+0x10/0x20 register_disk+0x155/0x170 add_disk+0xa6/0x160 sd_probe_async+0x13b/0x210 [sd_mod] add_wait_queue+0x46/0x60 async_thread+0x102/0x250 default_wake_function+0x0/0x20 async_thread+0x0/0x250 kthread+0x96/0xa0 child_rip+0xa/0x20 kthread+0x0/0xa0 child_rip+0x0/0x20 This most likely happens because dev_t is freed while the number is still used and idr_get_new() is not protected on every use. The fix adds a mutex where it wasn't before and moves the dev_t free function so it is called after device del. Signed-off-by: Tomas Henzl Cc: Jens Axboe Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

block: fix buffer overflow when printing partition UUIDs

2012-05-15T06:22:04+00:00

6d1d8050b4bc8 "block, partition: add partition_meta_info to hd_struct" added part_unpack_uuid() which assumes that the passed in buffer has enough space for sprintfing "%pU" - 37 characters including '\0'. Unfortunately, b5af921ec0233 "init: add support for root devices specified by partition UUID" supplied 33 bytes buffer to the function leading to the following panic with stackprotector enabled. Kernel panic - not syncing: stack-protector: Kernel stack corrupted in: ffffffff81b14c7e [] panic+0xba/0x1c6 [] ? printk_all_partitions+0x259/0x26xb [] __stack_chk_fail+0x1b/0x20 [] printk_all_paritions+0x259/0x26xb [] mount_block_root+0x1bc/0x27f [] mount_root+0x57/0x5b [] prepare_namespace+0x13d/0x176 [] ? release_tgcred.isra.4+0x330/0x30 [] kernel_init+0x155/0x15a [] ? schedule_tail+0x27/0xb0 [] kernel_thread_helper+0x5/0x10 [] ? start_kernel+0x3c5/0x3c5 [] ? gs_change+0x13/0x13 Increase the buffer size, remove the dangerous part_unpack_uuid() and use snprintf() directly from printk_all_partitions(). Signed-off-by: Tejun Heo Reported-by: Szymon Gruszczynski Cc: Will Drewry Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe

Block: use a freezable workqueue for disk-event polling

2012-03-02T09:51:00+00:00

This patch (as1519) fixes a bug in the block layer's disk-events polling. The polling is done by a work routine queued on the system_nrt_wq workqueue. Since that workqueue isn't freezable, the polling continues even in the middle of a system sleep transition. Obviously, polling a suspended drive for media changes and such isn't a good thing to do; in the case of USB mass-storage devices it can lead to real problems requiring device resets and even re-enumeration. The patch fixes things by creating a new system-wide, non-reentrant, freezable workqueue and using it for disk-events polling. Signed-off-by: Alan Stern CC: Acked-by: Tejun Heo Acked-by: Rafael J. Wysocki Signed-off-by: Jens Axboe

block: fix __blkdev_get and add_disk race condition

2012-03-02T09:44:17+00:00

The following situation might occur: __blkdev_get: add_disk: register_disk() get_gendisk() disk_block_events() disk->ev == NULL disk_add_events() __disk_unblock_events() disk->ev != NULL --ev->block Then we unblock events, when they are suppose to be blocked. This can trigger events related block/genhd.c warnings, but also can crash in sd_check_events() or other places. I'm able to reproduce crashes with the following scripts (with connected usb dongle as sdb disk). DEV=/dev/sdb ENABLE=/sys/bus/usb/devices/1-2/bConfigurationValue function stop_me() { for i in `jobs -p` ; do kill $i 2> /dev/null ; done exit } trap stop_me SIGHUP SIGINT SIGTERM for ((i = 0; i < 10; i++)) ; do while true; do fdisk -l $DEV 2>&1 > /dev/null ; done & done while true ; do echo 1 > $ENABLE sleep 1 echo 0 > $ENABLE done I use the script to verify patch fixing oops in sd_revalidate_disk http://marc.info/?l=linux-scsi&m=132935572512352&w=2 Without Jun'ichi Nomura patch titled "Fix NULL pointer dereference in sd_revalidate_disk" or this one, script easily crash kernel within a few seconds. With both patches applied I do not observe crash. Unfortunately after some time (dozen of minutes), script will hung in: [ 1563.906432] [] schedule_timeout_uninterruptible+0x15/0x20 [ 1563.906437] [] msleep+0x15/0x20 [ 1563.906443] [] blk_drain_queue+0x32/0xd0 [ 1563.906447] [] blk_cleanup_queue+0xd0/0x170 [ 1563.906454] [] scsi_free_queue+0x3f/0x60 [ 1563.906459] [] __scsi_remove_device+0x6e/0xb0 [ 1563.906463] [] scsi_forget_host+0x4f/0x60 [ 1563.906468] [] scsi_remove_host+0x5a/0xf0 [ 1563.906482] [] quiesce_and_remove_host+0x5b/0xa0 [usb_storage] [ 1563.906490] [] usb_stor_disconnect+0x13/0x20 [usb_storage] Anyway I think this patch is some step forward. As drawback, I do not teardown on sysfs file create error, because I do not know how to nullify disk->ev (since it can be used). However add_disk error handling practically does not exist too, and things will work without this sysfs file, except events will not be exported to user space. Signed-off-by: Stanislaw Gruszka Acked-by: Tejun Heo Cc: stable@kernel.org Signed-off-by: Jens Axboe