user/sven/linux.git, branch v4.17.4

Linux 4.17.4

2018-07-03T09:27:13Z

virt: vbox: Only copy_from_user the request-header once

2018-07-03T09:27:12Z

commit bd23a7269834dc7c1f93e83535d16ebc44b75eba upstream. In vbg_misc_device_ioctl(), the header of the ioctl argument is copied from the userspace pointer 'arg' and saved to the kernel object 'hdr'. Then the 'version', 'size_in', and 'size_out' fields of 'hdr' are verified. Before this commit, after the checks a buffer for the entire request would be allocated and then all data including the verified header would be copied from the userspace 'arg' pointer again. Given that the 'arg' pointer resides in userspace, a malicious userspace process can race to change the data pointed to by 'arg' between the two copies. By doing so, the user can bypass the verifications on the ioctl argument. This commit fixes this by using the already checked copy of the header to fill the header part of the allocated buffer and only copying the remainder of the data from userspace. Signed-off-by: Wenwen Wang Reviewed-by: Hans de Goede Cc: Justin Forbes Signed-off-by: Greg Kroah-Hartman

dm thin: handle running out of data space vs concurrent discard

2018-07-03T09:27:12Z

commit a685557fbbc3122ed11e8ad3fa63a11ebc5de8c3 upstream. Discards issued to a DM thin device can complete to userspace (via fstrim) _before_ the metadata changes associated with the discards is reflected in the thinp superblock (e.g. free blocks). As such, if a user constructs a test that loops repeatedly over these steps, block allocation can fail due to discards not having completed yet: 1) fill thin device via filesystem file 2) remove file 3) fstrim From initial report, here: https://www.redhat.com/archives/dm-devel/2018-April/msg00022.html "The root cause of this issue is that dm-thin will first remove mapping and increase corresponding blocks' reference count to prevent them from being reused before DISCARD bios get processed by the underlying layers. However. increasing blocks' reference count could also increase the nr_allocated_this_transaction in struct sm_disk which makes smd->old_ll.nr_allocated + smd->nr_allocated_this_transaction bigger than smd->old_ll.nr_blocks. In this case, alloc_data_block() will never commit metadata to reset the begin pointer of struct sm_disk, because sm_disk_get_nr_free() always return an underflow value." While there is room for improvement to the space-map accounting that thinp is making use of: the reality is this test is inherently racey and will result in the previous iteration's fstrim's discard(s) completing vs concurrent block allocation, via dd, in the next iteration of the loop. No amount of space map accounting improvements will be able to allow user's to use a block before a discard of that block has completed. So the best we can really do is allow DM thinp to gracefully handle such aggressive use of all the pool's data by degrading the pool into out-of-data-space (OODS) mode. We _should_ get that behaviour already (if space map accounting didn't falsely cause alloc_data_block() to believe free space was available).. but short of that we handle the current reality that dm_pool_alloc_data_block() can return -ENOSPC. Reported-by: Dennis Yang Cc: stable@vger.kernel.org Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman

dm zoned: avoid triggering reclaim from inside dmz_map()

2018-07-03T09:27:12Z

commit 2d0b2d64d325e22939d9db3ba784f1236459ed98 upstream. This patch avoids that lockdep reports the following: ====================================================== WARNING: possible circular locking dependency detected 4.18.0-rc1 #62 Not tainted ------------------------------------------------------ kswapd0/84 is trying to acquire lock: 00000000c313516d (&xfs_nondir_ilock_class){++++}, at: xfs_free_eofblocks+0xa2/0x1e0 but task is already holding lock: 00000000591c83ae (fs_reclaim){+.+.}, at: __fs_reclaim_acquire+0x5/0x30 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (fs_reclaim){+.+.}: kmem_cache_alloc+0x2c/0x2b0 radix_tree_node_alloc.constprop.19+0x3d/0xc0 __radix_tree_create+0x161/0x1c0 __radix_tree_insert+0x45/0x210 dmz_map+0x245/0x2d0 [dm_zoned] __map_bio+0x40/0x260 __split_and_process_non_flush+0x116/0x220 __split_and_process_bio+0x81/0x180 __dm_make_request.isra.32+0x5a/0x100 generic_make_request+0x36e/0x690 submit_bio+0x6c/0x140 mpage_readpages+0x19e/0x1f0 read_pages+0x6d/0x1b0 __do_page_cache_readahead+0x21b/0x2d0 force_page_cache_readahead+0xc4/0x100 generic_file_read_iter+0x7c6/0xd20 __vfs_read+0x102/0x180 vfs_read+0x9b/0x140 ksys_read+0x55/0xc0 do_syscall_64+0x5a/0x1f0 entry_SYSCALL_64_after_hwframe+0x49/0xbe -> #1 (&dmz->chunk_lock){+.+.}: dmz_map+0x133/0x2d0 [dm_zoned] __map_bio+0x40/0x260 __split_and_process_non_flush+0x116/0x220 __split_and_process_bio+0x81/0x180 __dm_make_request.isra.32+0x5a/0x100 generic_make_request+0x36e/0x690 submit_bio+0x6c/0x140 _xfs_buf_ioapply+0x31c/0x590 xfs_buf_submit_wait+0x73/0x520 xfs_buf_read_map+0x134/0x2f0 xfs_trans_read_buf_map+0xc3/0x580 xfs_read_agf+0xa5/0x1e0 xfs_alloc_read_agf+0x59/0x2b0 xfs_alloc_pagf_init+0x27/0x60 xfs_bmap_longest_free_extent+0x43/0xb0 xfs_bmap_btalloc_nullfb+0x7f/0xf0 xfs_bmap_btalloc+0x428/0x7c0 xfs_bmapi_write+0x598/0xcc0 xfs_iomap_write_allocate+0x15a/0x330 xfs_map_blocks+0x1cf/0x3f0 xfs_do_writepage+0x15f/0x7b0 write_cache_pages+0x1ca/0x540 xfs_vm_writepages+0x65/0xa0 do_writepages+0x48/0xf0 __writeback_single_inode+0x58/0x730 writeback_sb_inodes+0x249/0x5c0 wb_writeback+0x11e/0x550 wb_workfn+0xa3/0x670 process_one_work+0x228/0x670 worker_thread+0x3c/0x390 kthread+0x11c/0x140 ret_from_fork+0x3a/0x50 -> #0 (&xfs_nondir_ilock_class){++++}: down_read_nested+0x43/0x70 xfs_free_eofblocks+0xa2/0x1e0 xfs_fs_destroy_inode+0xac/0x270 dispose_list+0x51/0x80 prune_icache_sb+0x52/0x70 super_cache_scan+0x127/0x1a0 shrink_slab.part.47+0x1bd/0x590 shrink_node+0x3b5/0x470 balance_pgdat+0x158/0x3b0 kswapd+0x1ba/0x600 kthread+0x11c/0x140 ret_from_fork+0x3a/0x50 other info that might help us debug this: Chain exists of: &xfs_nondir_ilock_class --> &dmz->chunk_lock --> fs_reclaim Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(fs_reclaim); lock(&dmz->chunk_lock); lock(fs_reclaim); lock(&xfs_nondir_ilock_class);

x86/efi: Fix efi_call_phys_epilog() with CONFIG_X86_5LEVEL=y

2018-07-03T09:27:12Z

commit cfe19577047e74cdac5826adbdc2337d8437f8fb upstream. Open-coded page table entry checks don't work correctly when we fold the page table level at runtime. pgd_present() on 4-level paging machine always returns true, but open-coded version of the check may return false-negative result and we silently skip the rest of the loop body in efi_call_phys_epilog(). Replace open-coded checks with proper helpers. Signed-off-by: Kirill A. Shutemov Acked-by: Ard Biesheuvel Cc: Andrey Ryabinin Cc: Baoquan He Cc: Linus Torvalds Cc: Matt Fleming Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: stable@vger.kernel.org # v4.12+ Fixes: 94133e46a0f5 ("x86/efi: Correct EFI identity mapping under 'efi=old_map' when KASLR is enabled") Link: http://lkml.kernel.org/r/20180625120852.18300-1-kirill.shutemov@linux.intel.com Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

x86/entry/64/compat: Fix "x86/entry/64/compat: Preserve r8-r11 in int $0x80"

2018-07-03T09:27:12Z

commit 22cd978e598618e82c3c3348d2069184f6884182 upstream. Commit: 8bb2610bc496 ("x86/entry/64/compat: Preserve r8-r11 in int $0x80") was busted: my original patch had a minor conflict with some of the nospec changes, but "git apply" is very clever and silently accepted the patch by making the same changes to a different function in the same file. There was obviously a huge offset, but "git apply" for some reason doesn't feel any need to say so. Move the changes to the correct function. Now the test_syscall_vdso_32 selftests passes. If anyone cares to observe the original problem, try applying the patch at: https://lore.kernel.org/lkml/d4c4d9985fbe64f8c9e19291886453914b48caee.1523975710.git.luto@kernel.org/raw to the kernel at 316d097c4cd4e7f2ef50c40cff2db266593c4ec4: - "git am" and "git apply" accept the patch without any complaints at all - "patch -p1" at least prints out a message about the huge offset. Reported-by: zhijianx.li@intel.com Signed-off-by: Andy Lutomirski Cc: Arjan van de Ven Cc: Borislav Petkov Cc: Dan Williams Cc: Dave Hansen Cc: David Woodhouse Cc: Greg Kroah-Hartman Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: stable@vger.kernel.org #v4.17+ Fixes: 8bb2610bc496 ("x86/entry/64/compat: Preserve r8-r11 in int $0x80") Link: http://lkml.kernel.org/r/6012b922485401bc42676e804171ded262fc2ef2.1530078306.git.luto@kernel.org Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman

selinux: move user accesses in selinuxfs out of locked regions

2018-07-03T09:27:12Z

commit 0da74120c5341389b97c4ee27487a97224999ee1 upstream. If a user is accessing a file in selinuxfs with a pointer to a userspace buffer that is backed by e.g. a userfaultfd, the userspace access can stall indefinitely, which can block fsi->mutex if it is held. For sel_read_policy(), remove the locking, since this method doesn't seem to access anything that requires locking. For sel_read_bool(), move the user access below the locked region. For sel_write_bool() and sel_commit_bools_write(), move the user access up above the locked region. Cc: stable@vger.kernel.org Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Jann Horn Acked-by: Stephen Smalley [PM: removed an unused variable in sel_read_policy()] Signed-off-by: Paul Moore Signed-off-by: Greg Kroah-Hartman

x86/e820: put !E820_TYPE_RAM regions into memblock.reserved

2018-07-03T09:27:12Z

commit 124049decbb121ec32742c94fb5d9d6bed8f24d8 upstream. There is a kernel panic that is triggered when reading /proc/kpageflags on the kernel booted with kernel parameter 'memmap=nn[KMG]!ss[KMG]': BUG: unable to handle kernel paging request at fffffffffffffffe PGD 9b20e067 P4D 9b20e067 PUD 9b210067 PMD 0 Oops: 0000 [#1] SMP PTI CPU: 2 PID: 1728 Comm: page-types Not tainted 4.17.0-rc6-mm1-v4.17-rc6-180605-0816-00236-g2dfb086ef02c+ #160 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.fc28 04/01/2014 RIP: 0010:stable_page_flags+0x27/0x3c0 Code: 00 00 00 0f 1f 44 00 00 48 85 ff 0f 84 a0 03 00 00 41 54 55 49 89 fc 53 48 8b 57 08 48 8b 2f 48 8d 42 ff 83 e2 01 48 0f 44 c7 <48> 8b 00 f6 c4 01 0f 84 10 03 00 00 31 db 49 8b 54 24 08 4c 89 e7 RSP: 0018:ffffbbd44111fde0 EFLAGS: 00010202 RAX: fffffffffffffffe RBX: 00007fffffffeff9 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000202 RDI: ffffed1182fff5c0 RBP: ffffffffffffffff R08: 0000000000000001 R09: 0000000000000001 R10: ffffbbd44111fed8 R11: 0000000000000000 R12: ffffed1182fff5c0 R13: 00000000000bffd7 R14: 0000000002fff5c0 R15: ffffbbd44111ff10 FS: 00007efc4335a500(0000) GS:ffff93a5bfc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffffffffffffffe CR3: 00000000b2a58000 CR4: 00000000001406e0 Call Trace: kpageflags_read+0xc7/0x120 proc_reg_read+0x3c/0x60 __vfs_read+0x36/0x170 vfs_read+0x89/0x130 ksys_pread64+0x71/0x90 do_syscall_64+0x5b/0x160 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7efc42e75e23 Code: 09 00 ba 9f 01 00 00 e8 ab 81 f4 ff 66 2e 0f 1f 84 00 00 00 00 00 90 83 3d 29 0a 2d 00 00 75 13 49 89 ca b8 11 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 db d3 01 00 48 89 04 24 According to kernel bisection, this problem became visible due to commit f7f99100d8d9 ("mm: stop zeroing memory during allocation in vmemmap") which changes how struct pages are initialized. Memblock layout affects the pfn ranges covered by node/zone. Consider that we have a VM with 2 NUMA nodes and each node has 4GB memory, and the default (no memmap= given) memblock layout is like below: MEMBLOCK configuration: memory size = 0x00000001fff75c00 reserved size = 0x000000000300c000 memory.cnt = 0x4 memory[0x0] [0x0000000000001000-0x000000000009efff], 0x000000000009e000 bytes on node 0 flags: 0x0 memory[0x1] [0x0000000000100000-0x00000000bffd6fff], 0x00000000bfed7000 bytes on node 0 flags: 0x0 memory[0x2] [0x0000000100000000-0x000000013fffffff], 0x0000000040000000 bytes on node 0 flags: 0x0 memory[0x3] [0x0000000140000000-0x000000023fffffff], 0x0000000100000000 bytes on node 1 flags: 0x0 ... If you give memmap=1G!4G (so it just covers memory[0x2]), the range [0x100000000-0x13fffffff] is gone: MEMBLOCK configuration: memory size = 0x00000001bff75c00 reserved size = 0x000000000300c000 memory.cnt = 0x3 memory[0x0] [0x0000000000001000-0x000000000009efff], 0x000000000009e000 bytes on node 0 flags: 0x0 memory[0x1] [0x0000000000100000-0x00000000bffd6fff], 0x00000000bfed7000 bytes on node 0 flags: 0x0 memory[0x2] [0x0000000140000000-0x000000023fffffff], 0x0000000100000000 bytes on node 1 flags: 0x0 ... This causes shrinking node 0's pfn range because it is calculated by the address range of memblock.memory. So some of struct pages in the gap range are left uninitialized. We have a function zero_resv_unavail() which does zeroing the struct pages within the reserved unavailable range (i.e. memblock.memory && !memblock.reserved). This patch utilizes it to cover all unavailable ranges by putting them into memblock.reserved. Link: http://lkml.kernel.org/r/20180615072947.GB23273@hori1.linux.bs1.fc.nec.co.jp Fixes: f7f99100d8d9 ("mm: stop zeroing memory during allocation in vmemmap") Signed-off-by: Naoya Horiguchi Tested-by: Oscar Salvador Tested-by: "Herton R. Krzesinski" Acked-by: Michal Hocko Reviewed-by: Pavel Tatashin Cc: Steven Sistare Cc: Daniel Jordan Cc: Matthew Wilcox Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman

block: Fix cloning of requests with a special payload

2018-07-03T09:27:11Z

commit 297ba57dcdec7ea37e702bcf1a577ac32a034e21 upstream. This patch avoids that removing a path controlled by the dm-mpath driver while mkfs is running triggers the following kernel bug: kernel BUG at block/blk-core.c:3347! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 20 PID: 24369 Comm: mkfs.ext4 Not tainted 4.18.0-rc1-dbg+ #2 RIP: 0010:blk_end_request_all+0x68/0x70 Call Trace: dm_softirq_done+0x326/0x3d0 [dm_mod] blk_done_softirq+0x19b/0x1e0 __do_softirq+0x128/0x60d irq_exit+0x100/0x110 smp_call_function_single_interrupt+0x90/0x330 call_function_single_interrupt+0xf/0x20 Fixes: f9d03f96b988 ("block: improve handling of the magic discard payload") Reviewed-by: Ming Lei Reviewed-by: Christoph Hellwig Acked-by: Mike Snitzer Signed-off-by: Bart Van Assche Cc: Hannes Reinecke Cc: Johannes Thumshirn Cc: Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman

block: Fix transfer when chunk sectors exceeds max

2018-07-03T09:27:11Z

commit 15bfd21fbc5d35834b9ea383dc458a1f0c9e3434 upstream. A device may have boundary restrictions where the number of sectors between boundaries exceeds its max transfer size. In this case, we need to cap the max size to the smaller of the two limits. Reported-by: Jitendra Bhivare Tested-by: Jitendra Bhivare Cc: Reviewed-by: Martin K. Petersen Signed-off-by: Keith Busch Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman