kernel/linux.git/drivers/block, branch v4.14.85

floppy: fix race condition in __floppy_read_block_0()

2018-12-01T08:42:53+00:00

[ Upstream commit de7b75d82f70c5469675b99ad632983c50b6f7e7 ] LKP recently reported a hang at bootup in the floppy code: [ 245.678853] INFO: task mount:580 blocked for more than 120 seconds. [ 245.679906] Tainted: G T 4.19.0-rc6-00172-ga9f38e1 #1 [ 245.680959] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. [ 245.682181] mount D 6372 580 1 0x00000004 [ 245.683023] Call Trace: [ 245.683425] __schedule+0x2df/0x570 [ 245.683975] schedule+0x2d/0x80 [ 245.684476] schedule_timeout+0x19d/0x330 [ 245.685090] ? wait_for_common+0xa5/0x170 [ 245.685735] wait_for_common+0xac/0x170 [ 245.686339] ? do_sched_yield+0x90/0x90 [ 245.686935] wait_for_completion+0x12/0x20 [ 245.687571] __floppy_read_block_0+0xfb/0x150 [ 245.688244] ? floppy_resume+0x40/0x40 [ 245.688844] floppy_revalidate+0x20f/0x240 [ 245.689486] check_disk_change+0x43/0x60 [ 245.690087] floppy_open+0x1ea/0x360 [ 245.690653] __blkdev_get+0xb4/0x4d0 [ 245.691212] ? blkdev_get+0x1db/0x370 [ 245.691777] blkdev_get+0x1f3/0x370 [ 245.692351] ? path_put+0x15/0x20 [ 245.692871] ? lookup_bdev+0x4b/0x90 [ 245.693539] blkdev_get_by_path+0x3d/0x80 [ 245.694165] mount_bdev+0x2a/0x190 [ 245.694695] squashfs_mount+0x10/0x20 [ 245.695271] ? squashfs_alloc_inode+0x30/0x30 [ 245.695960] mount_fs+0xf/0x90 [ 245.696451] vfs_kern_mount+0x43/0x130 [ 245.697036] do_mount+0x187/0xc40 [ 245.697563] ? memdup_user+0x28/0x50 [ 245.698124] ksys_mount+0x60/0xc0 [ 245.698639] sys_mount+0x19/0x20 [ 245.699167] do_int80_syscall_32+0x61/0x130 [ 245.699813] entry_INT80_32+0xc7/0xc7 showing that we never complete that read request. The reason is that the completion setup is racy - it initializes the completion event AFTER submitting the IO, which means that the IO could complete before/during the init. If it does, we are passing garbage to complete() and we may sleep forever waiting for the event to occur. Fixes: 7b7b68bba5ef ("floppy: bail out in open() if drive is not responding to block0 read") Reviewed-by: Omar Sandoval Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

zram: close udev startup race condition as default groups

2018-11-27T15:10:49+00:00

commit fef912bf860e upstream. commit 98af4d4df889 upstream. I got a report from Howard Chen that he saw zram and sysfs race(ie, zram block device file is created but sysfs for it isn't yet) when he tried to create new zram devices via hotadd knob. v4.20 kernel fixes it by [1, 2] but it's too large size to merge into -stable so this patch fixes the problem by registering defualt group by Greg KH's approach[3]. This patch should be applied to every stable tree [3.16+] currently existing from kernel.org because the problem was introduced at 2.6.37 by [4]. [1] fef912bf860e, block: genhd: add 'groups' argument to device_add_disk [2] 98af4d4df889, zram: register default groups with device_add_disk() [3] http://kroah.com/log/blog/2013/06/26/how-to-create-a-sysfs-file-correctly/ [4] 33863c21e69e9, Staging: zram: Replace ioctls with sysfs interface Cc: Sergey Senozhatsky Cc: Hannes Reinecke Tested-by: Howard Chen Signed-off-by: Minchan Kim Signed-off-by: Sasha Levin

xen-blkfront: fix kernel panic with negotiate_mq error path

2018-11-13T19:15:11+00:00

commit 6cc4a0863c9709c512280c64e698d68443ac8053 upstream. info->nr_rings isn't adjusted in case of ENOMEM error from negotiate_mq(). This leads to kernel panic in error path. Typical call stack involving panic - #8 page_fault at ffffffff8175936f [exception RIP: blkif_free_ring+33] RIP: ffffffffa0149491 RSP: ffff8804f7673c08 RFLAGS: 00010292 ... #9 blkif_free at ffffffffa0149aaa [xen_blkfront] #10 talk_to_blkback at ffffffffa014c8cd [xen_blkfront] #11 blkback_changed at ffffffffa014ea8b [xen_blkfront] #12 xenbus_otherend_changed at ffffffff81424670 #13 backend_changed at ffffffff81426dc3 #14 xenwatch_thread at ffffffff81422f29 #15 kthread at ffffffff810abe6a #16 ret_from_fork at ffffffff81754078 Cc: stable@vger.kernel.org Fixes: 7ed8ce1c5fc7 ("xen-blkfront: move negotiate_mq to cover all cases of new VBDs") Signed-off-by: Manjunath Patil Acked-by: Roger Pau Monné Signed-off-by: Juergen Gross Signed-off-by: Greg Kroah-Hartman

xen/blkfront: avoid NULL blkfront_info dereference on device removal

2018-11-13T19:15:02+00:00

commit f92898e7f32e3533bfd95be174044bc349d416ca upstream. If a block device is hot-added when we are out of grants, gnttab_grant_foreign_access fails with -ENOSPC (log message "28 granting access to ring page") in this code path: talk_to_blkback -> setup_blkring -> xenbus_grant_ring -> gnttab_grant_foreign_access and the failing path in talk_to_blkback sets the driver_data to NULL: destroy_blkring: blkif_free(info, 0); mutex_lock(&blkfront_mutex); free_info(info); mutex_unlock(&blkfront_mutex); dev_set_drvdata(&dev->dev, NULL); This results in a NULL pointer BUG when blkfront_remove and blkif_free try to access the failing device's NULL struct blkfront_info. Cc: stable@vger.kernel.org # 4.5 and later Signed-off-by: Vasilis Liaskovitis Reviewed-by: Roger Pau Monné Signed-off-by: Konrad Rzeszutek Wilk Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

swim: fix cleanup on setup error

2018-11-13T19:14:52+00:00

[ Upstream commit 1448a2a5360ae06f25e2edc61ae070dff5c0beb4 ] If we fail to allocate the request queue for a disk, we still need to free that disk, not just the previous ones. Additionally, we need to cleanup the previous request queues. Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

ataflop: fix error handling during setup

2018-11-13T19:14:51+00:00

[ Upstream commit 71327f547ee3a46ec5c39fdbbd268401b2578d0e ] Move queue allocation next to disk allocation to fix a couple of issues: - If add_disk() hasn't been called, we should clear disk->queue before calling put_disk(). - If we fail to allocate a request queue, we still need to put all of the disks, not just the ones that we allocated queues for. Signed-off-by: Omar Sandoval Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

floppy: Do not copy a kernel pointer to user memory in FDGETPRM ioctl

2018-10-04T00:00:54+00:00

commit 65eea8edc315589d6c993cf12dbb5d0e9ef1fe4e upstream. The final field of a floppy_struct is the field "name", which is a pointer to a string in kernel memory. The kernel pointer should not be copied to user memory. The FDGETPRM ioctl copies a floppy_struct to user memory, including this "name" field. This pointer cannot be used by the user and it will leak a kernel address to user-space, which will reveal the location of kernel code and data and undermine KASLR protection. Model this code after the compat ioctl which copies the returned data to a previously cleared temporary structure on the stack (excluding the name pointer) and copy out to userspace from there. As we already have an inparam union with an appropriate member and that memory is already cleared even for read only calls make use of that as a temporary store. Based on an initial patch by Brian Belleville. CVE-2018-7755 Signed-off-by: Andy Whitcroft Broke up long line. Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

pktcdvd: Fix possible Spectre-v1 for pkt_devs

2018-09-19T20:43:43+00:00

[ Upstream commit 55690c07b44a82cc3359ce0c233f4ba7d80ba145 ] User controls @dev_minor which to be used as index of pkt_devs. So, It can be exploited via Spectre-like attack. (speculative execution) This kind of attack leaks address of pkt_devs, [1] It leads an attacker to bypass security mechanism such as KASLR. So sanitize @dev_minor before using it to prevent attack. [1] https://github.com/jinb-park/linux-exploit/ tree/master/exploit-remaining-spectre-gadget/leak_pkt_devs.c Signed-off-by: Jinbum Park Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

nbd: don't allow invalid blocksize settings

2018-09-19T20:43:35+00:00

commit bc811f05d77f47059c197a98b6ad242eb03999cb upstream. syzbot reports a divide-by-zero off the NBD_SET_BLKSIZE ioctl. We need proper validation of the input here. Not just if it's zero, but also if the value is a power-of-2 and in a valid range. Add that. Cc: stable@vger.kernel.org Reported-by: syzbot Reviewed-by: Josef Bacik Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

drivers/block/zram/zram_drv.c: fix bug storing backing_dev

2018-09-09T17:55:58+00:00

commit c8bd134a4bddafe5917d163eea73873932c15e83 upstream. The call to strlcpy in backing_dev_store is incorrect. It should take the size of the destination buffer instead of the size of the source buffer. Additionally, ignore the newline character (\n) when reading the new file_name buffer. This makes it possible to set the backing_dev as follows: echo /dev/sdX > /sys/block/zram0/backing_dev The reason it worked before was the fact that strlcpy() copies 'len - 1' bytes, which is strlen(buf) - 1 in our case, so it accidentally didn't copy the trailing new line symbol. Which also means that "echo -n /dev/sdX" most likely was broken. Signed-off-by: Peter Kalauskas Link: http://lkml.kernel.org/r/20180813061623.GC64836@rodete-desktop-imager.corp.google.com Acked-by: Minchan Kim Reviewed-by: Sergey Senozhatsky Cc: [4.14+] Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman