linux-stable.git, branch v4.4.248 Linux kernel stable tree Linux 4.4.248 2020-12-11T12:36:47+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2020-12-11T12:36:47+00:00 f299fb634f3b99d7462b2321c3ccf6773812a44e Tested-by: Pavel Machek (CIP) <pavel@denx.de> Tested-by: Jon Hunter <jonathanh@nvidia.com> Tested-by: Shuah Khan <skhan@linuxfoundation.org> Tested-by: Guenter Roeck <linux@roeck-us.net> Link: https://lore.kernel.org/r/20201210142600.887734129@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
Tested-by: Pavel Machek (CIP) <pavel@denx.de>
Tested-by: Jon Hunter <jonathanh@nvidia.com>
Tested-by: Shuah Khan <skhan@linuxfoundation.org>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20201210142600.887734129@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86/uprobes: Do not use prefixes.nbytes when looping over prefixes.bytes 2020-12-11T12:36:46+00:00 Masami Hiramatsu mhiramat@kernel.org 2020-12-03T04:50:37+00:00 ec5aa25d75833ad6090cb11f1a696e4c9274bcf2 commit 4e9a5ae8df5b3365183150f6df49e49dece80d8c upstream Since insn.prefixes.nbytes can be bigger than the size of insn.prefixes.bytes[] when a prefix is repeated, the proper check must be insn.prefixes.bytes[i] != 0 and i < 4 instead of using insn.prefixes.nbytes. Introduce a for_each_insn_prefix() macro for this purpose. Debugged by Kees Cook <keescook@chromium.org>. [ bp: Massage commit message, sync with the respective header in tools/ and drop "we". ] Fixes: 2b1444983508 ("uprobes, mm, x86: Add the ability to install and remove uprobes breakpoints") Reported-by: syzbot+9b64b619f10f19d19a7c@syzkaller.appspotmail.com Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Cc: stable@vger.kernel.org Link: https://lkml.kernel.org/r/160697103739.3146288.7437620795200799020.stgit@devnote2 [sudip: adjust context, drop change of insn.h in tools] Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 4e9a5ae8df5b3365183150f6df49e49dece80d8c upstream

Since insn.prefixes.nbytes can be bigger than the size of
insn.prefixes.bytes[] when a prefix is repeated, the proper check must
be

  insn.prefixes.bytes[i] != 0 and i < 4

instead of using insn.prefixes.nbytes.

Introduce a for_each_insn_prefix() macro for this purpose. Debugged by
Kees Cook <keescook@chromium.org>.

 [ bp: Massage commit message, sync with the respective header in tools/
   and drop "we". ]

Fixes: 2b1444983508 ("uprobes, mm, x86: Add the ability to install and remove uprobes breakpoints")
Reported-by: syzbot+9b64b619f10f19d19a7c@syzkaller.appspotmail.com
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Reviewed-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Link: https://lkml.kernel.org/r/160697103739.3146288.7437620795200799020.stgit@devnote2
[sudip: adjust context, drop change of insn.h in tools]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Input: i8042 - fix error return code in i8042_setup_aux() 2020-12-11T12:36:46+00:00 Luo Meng luomeng12@huawei.com 2020-11-25T01:45:23+00:00 e233035a2ce6db6284f0ae1ca254e2beafd2293b commit 855b69857830f8d918d715014f05e59a3f7491a0 upstream. Fix to return a negative error code from the error handling case instead of 0 in function i8042_setup_aux(), as done elsewhere in this function. Fixes: f81134163fc7 ("Input: i8042 - use platform_driver_probe") Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Luo Meng <luomeng12@huawei.com> Reviewed-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20201123133420.4071187-1-luomeng12@huawei.com Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 855b69857830f8d918d715014f05e59a3f7491a0 upstream.

Fix to return a negative error code from the error handling case
instead of 0 in function i8042_setup_aux(), as done elsewhere in this
function.

Fixes: f81134163fc7 ("Input: i8042 - use platform_driver_probe")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Luo Meng <luomeng12@huawei.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20201123133420.4071187-1-luomeng12@huawei.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
gfs2: check for empty rgrp tree in gfs2_ri_update 2020-12-11T12:36:46+00:00 Bob Peterson rpeterso@redhat.com 2020-11-24T15:44:36+00:00 3bce763601f9c9fc1df4fa4658d3fbf1939d0463 commit 778721510e84209f78e31e2ccb296ae36d623f5e upstream. If gfs2 tries to mount a (corrupt) file system that has no resource groups it still tries to set preferences on the first one, which causes a kernel null pointer dereference. This patch adds a check to function gfs2_ri_update so this condition is detected and reported back as an error. Reported-by: syzbot+e3f23ce40269a4c9053a@syzkaller.appspotmail.com Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 778721510e84209f78e31e2ccb296ae36d623f5e upstream.

If gfs2 tries to mount a (corrupt) file system that has no resource
groups it still tries to set preferences on the first one, which causes
a kernel null pointer dereference. This patch adds a check to function
gfs2_ri_update so this condition is detected and reported back as an
error.

Reported-by: syzbot+e3f23ce40269a4c9053a@syzkaller.appspotmail.com
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
mm/userfaultfd: do not access vma->vm_mm after calling handle_userfault() 2020-12-11T12:36:46+00:00 Gerald Schaefer gerald.schaefer@linux.ibm.com 2020-11-22T06:17:15+00:00 a96661f5554d300536419e17d834d9b187d26ac7 commit bfe8cc1db02ab243c62780f17fc57f65bde0afe1 upstream. Alexander reported a syzkaller / KASAN finding on s390, see below for complete output. In do_huge_pmd_anonymous_page(), the pre-allocated pagetable will be freed in some cases. In the case of userfaultfd_missing(), this will happen after calling handle_userfault(), which might have released the mmap_lock. Therefore, the following pte_free(vma->vm_mm, pgtable) will access an unstable vma->vm_mm, which could have been freed or re-used already. For all architectures other than s390 this will go w/o any negative impact, because pte_free() simply frees the page and ignores the passed-in mm. The implementation for SPARC32 would also access mm->page_table_lock for pte_free(), but there is no THP support in SPARC32, so the buggy code path will not be used there. For s390, the mm->context.pgtable_list is being used to maintain the 2K pagetable fragments, and operating on an already freed or even re-used mm could result in various more or less subtle bugs due to list / pagetable corruption. Fix this by calling pte_free() before handle_userfault(), similar to how it is already done in __do_huge_pmd_anonymous_page() for the WRITE / non-huge_zero_page case. Commit 6b251fc96cf2c ("userfaultfd: call handle_userfault() for userfaultfd_missing() faults") actually introduced both, the do_huge_pmd_anonymous_page() and also __do_huge_pmd_anonymous_page() changes wrt to calling handle_userfault(), but only in the latter case it put the pte_free() before calling handle_userfault(). BUG: KASAN: use-after-free in do_huge_pmd_anonymous_page+0xcda/0xd90 mm/huge_memory.c:744 Read of size 8 at addr 00000000962d6988 by task syz-executor.0/9334 CPU: 1 PID: 9334 Comm: syz-executor.0 Not tainted 5.10.0-rc1-syzkaller-07083-g4c9720875573 #0 Hardware name: IBM 3906 M04 701 (KVM/Linux) Call Trace: do_huge_pmd_anonymous_page+0xcda/0xd90 mm/huge_memory.c:744 create_huge_pmd mm/memory.c:4256 [inline] __handle_mm_fault+0xe6e/0x1068 mm/memory.c:4480 handle_mm_fault+0x288/0x748 mm/memory.c:4607 do_exception+0x394/0xae0 arch/s390/mm/fault.c:479 do_dat_exception+0x34/0x80 arch/s390/mm/fault.c:567 pgm_check_handler+0x1da/0x22c arch/s390/kernel/entry.S:706 copy_from_user_mvcos arch/s390/lib/uaccess.c:111 [inline] raw_copy_from_user+0x3a/0x88 arch/s390/lib/uaccess.c:174 _copy_from_user+0x48/0xa8 lib/usercopy.c:16 copy_from_user include/linux/uaccess.h:192 [inline] __do_sys_sigaltstack kernel/signal.c:4064 [inline] __s390x_sys_sigaltstack+0xc8/0x240 kernel/signal.c:4060 system_call+0xe0/0x28c arch/s390/kernel/entry.S:415 Allocated by task 9334: slab_alloc_node mm/slub.c:2891 [inline] slab_alloc mm/slub.c:2899 [inline] kmem_cache_alloc+0x118/0x348 mm/slub.c:2904 vm_area_dup+0x9c/0x2b8 kernel/fork.c:356 __split_vma+0xba/0x560 mm/mmap.c:2742 split_vma+0xca/0x108 mm/mmap.c:2800 mlock_fixup+0x4ae/0x600 mm/mlock.c:550 apply_vma_lock_flags+0x2c6/0x398 mm/mlock.c:619 do_mlock+0x1aa/0x718 mm/mlock.c:711 __do_sys_mlock2 mm/mlock.c:738 [inline] __s390x_sys_mlock2+0x86/0xa8 mm/mlock.c:728 system_call+0xe0/0x28c arch/s390/kernel/entry.S:415 Freed by task 9333: slab_free mm/slub.c:3142 [inline] kmem_cache_free+0x7c/0x4b8 mm/slub.c:3158 __vma_adjust+0x7b2/0x2508 mm/mmap.c:960 vma_merge+0x87e/0xce0 mm/mmap.c:1209 userfaultfd_release+0x412/0x6b8 fs/userfaultfd.c:868 __fput+0x22c/0x7a8 fs/file_table.c:281 task_work_run+0x200/0x320 kernel/task_work.c:151 tracehook_notify_resume include/linux/tracehook.h:188 [inline] do_notify_resume+0x100/0x148 arch/s390/kernel/signal.c:538 system_call+0xe6/0x28c arch/s390/kernel/entry.S:416 The buggy address belongs to the object at 00000000962d6948 which belongs to the cache vm_area_struct of size 200 The buggy address is located 64 bytes inside of 200-byte region [00000000962d6948, 00000000962d6a10) The buggy address belongs to the page: page:00000000313a09fe refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x962d6 flags: 0x3ffff00000000200(slab) raw: 3ffff00000000200 000040000257e080 0000000c0000000c 000000008020ba00 raw: 0000000000000000 000f001e00000000 ffffffff00000001 0000000096959501 page dumped because: kasan: bad access detected page->mem_cgroup:0000000096959501 Memory state around the buggy address: 00000000962d6880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00000000962d6900: 00 fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb >00000000962d6980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ 00000000962d6a00: fb fb fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00000000962d6a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== Changes for v4.4 stable: - Make it apply w/o * Commit 4cf58924951ef ("mm: treewide: remove unused address argument from pte_alloc functions") * Commit 2b7403035459c ("mm: Change return type int to vm_fault_t for fault handlers") * Commit 82b0f8c39a386 ("mm: join struct fault_env and vm_fault") * Commit bae473a423f65 ("mm: introduce fault_env") * Commit 6fcb52a56ff60 ("thp: reduce usage of huge zero page's atomic counter") Fixes: 6b251fc96cf2c ("userfaultfd: call handle_userfault() for userfaultfd_missing() faults") Reported-by: Alexander Egorenkov <egorenar@linux.ibm.com> Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: <stable@vger.kernel.org> [4.3+] Link: https://lkml.kernel.org/r/20201110190329.11920-1-gerald.schaefer@linux.ibm.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit bfe8cc1db02ab243c62780f17fc57f65bde0afe1 upstream.

Alexander reported a syzkaller / KASAN finding on s390, see below for
complete output.

In do_huge_pmd_anonymous_page(), the pre-allocated pagetable will be
freed in some cases.  In the case of userfaultfd_missing(), this will
happen after calling handle_userfault(), which might have released the
mmap_lock.  Therefore, the following pte_free(vma->vm_mm, pgtable) will
access an unstable vma->vm_mm, which could have been freed or re-used
already.

For all architectures other than s390 this will go w/o any negative
impact, because pte_free() simply frees the page and ignores the
passed-in mm.  The implementation for SPARC32 would also access
mm->page_table_lock for pte_free(), but there is no THP support in
SPARC32, so the buggy code path will not be used there.

For s390, the mm->context.pgtable_list is being used to maintain the 2K
pagetable fragments, and operating on an already freed or even re-used
mm could result in various more or less subtle bugs due to list /
pagetable corruption.

Fix this by calling pte_free() before handle_userfault(), similar to how
it is already done in __do_huge_pmd_anonymous_page() for the WRITE /
non-huge_zero_page case.

Commit 6b251fc96cf2c ("userfaultfd: call handle_userfault() for
userfaultfd_missing() faults") actually introduced both, the
do_huge_pmd_anonymous_page() and also __do_huge_pmd_anonymous_page()
changes wrt to calling handle_userfault(), but only in the latter case
it put the pte_free() before calling handle_userfault().

  BUG: KASAN: use-after-free in do_huge_pmd_anonymous_page+0xcda/0xd90 mm/huge_memory.c:744
  Read of size 8 at addr 00000000962d6988 by task syz-executor.0/9334

  CPU: 1 PID: 9334 Comm: syz-executor.0 Not tainted 5.10.0-rc1-syzkaller-07083-g4c9720875573 #0
  Hardware name: IBM 3906 M04 701 (KVM/Linux)
  Call Trace:
    do_huge_pmd_anonymous_page+0xcda/0xd90 mm/huge_memory.c:744
    create_huge_pmd mm/memory.c:4256 [inline]
    __handle_mm_fault+0xe6e/0x1068 mm/memory.c:4480
    handle_mm_fault+0x288/0x748 mm/memory.c:4607
    do_exception+0x394/0xae0 arch/s390/mm/fault.c:479
    do_dat_exception+0x34/0x80 arch/s390/mm/fault.c:567
    pgm_check_handler+0x1da/0x22c arch/s390/kernel/entry.S:706
    copy_from_user_mvcos arch/s390/lib/uaccess.c:111 [inline]
    raw_copy_from_user+0x3a/0x88 arch/s390/lib/uaccess.c:174
    _copy_from_user+0x48/0xa8 lib/usercopy.c:16
    copy_from_user include/linux/uaccess.h:192 [inline]
    __do_sys_sigaltstack kernel/signal.c:4064 [inline]
    __s390x_sys_sigaltstack+0xc8/0x240 kernel/signal.c:4060
    system_call+0xe0/0x28c arch/s390/kernel/entry.S:415

  Allocated by task 9334:
    slab_alloc_node mm/slub.c:2891 [inline]
    slab_alloc mm/slub.c:2899 [inline]
    kmem_cache_alloc+0x118/0x348 mm/slub.c:2904
    vm_area_dup+0x9c/0x2b8 kernel/fork.c:356
    __split_vma+0xba/0x560 mm/mmap.c:2742
    split_vma+0xca/0x108 mm/mmap.c:2800
    mlock_fixup+0x4ae/0x600 mm/mlock.c:550
    apply_vma_lock_flags+0x2c6/0x398 mm/mlock.c:619
    do_mlock+0x1aa/0x718 mm/mlock.c:711
    __do_sys_mlock2 mm/mlock.c:738 [inline]
    __s390x_sys_mlock2+0x86/0xa8 mm/mlock.c:728
    system_call+0xe0/0x28c arch/s390/kernel/entry.S:415

  Freed by task 9333:
    slab_free mm/slub.c:3142 [inline]
    kmem_cache_free+0x7c/0x4b8 mm/slub.c:3158
    __vma_adjust+0x7b2/0x2508 mm/mmap.c:960
    vma_merge+0x87e/0xce0 mm/mmap.c:1209
    userfaultfd_release+0x412/0x6b8 fs/userfaultfd.c:868
    __fput+0x22c/0x7a8 fs/file_table.c:281
    task_work_run+0x200/0x320 kernel/task_work.c:151
    tracehook_notify_resume include/linux/tracehook.h:188 [inline]
    do_notify_resume+0x100/0x148 arch/s390/kernel/signal.c:538
    system_call+0xe6/0x28c arch/s390/kernel/entry.S:416

  The buggy address belongs to the object at 00000000962d6948 which belongs to the cache vm_area_struct of size 200
  The buggy address is located 64 bytes inside of 200-byte region [00000000962d6948, 00000000962d6a10)
  The buggy address belongs to the page: page:00000000313a09fe refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x962d6 flags: 0x3ffff00000000200(slab)
  raw: 3ffff00000000200 000040000257e080 0000000c0000000c 000000008020ba00
  raw: 0000000000000000 000f001e00000000 ffffffff00000001 0000000096959501
  page dumped because: kasan: bad access detected
  page->mem_cgroup:0000000096959501

  Memory state around the buggy address:
   00000000962d6880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
   00000000962d6900: 00 fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb
  >00000000962d6980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                        ^
   00000000962d6a00: fb fb fc fc fc fc fc fc fc fc 00 00 00 00 00 00
   00000000962d6a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  ==================================================================

Changes for v4.4 stable:
  - Make it apply w/o
    * Commit 4cf58924951ef ("mm: treewide: remove unused address argument
      from pte_alloc functions")
    * Commit 2b7403035459c ("mm: Change return type int to vm_fault_t for
      fault handlers")
    * Commit 82b0f8c39a386 ("mm: join struct fault_env and vm_fault")
    * Commit bae473a423f65 ("mm: introduce fault_env")
    * Commit 6fcb52a56ff60 ("thp: reduce usage of huge zero page's atomic counter")

Fixes: 6b251fc96cf2c ("userfaultfd: call handle_userfault() for userfaultfd_missing() faults")
Reported-by: Alexander Egorenkov <egorenar@linux.ibm.com>
Signed-off-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: <stable@vger.kernel.org>	[4.3+]
Link: https://lkml.kernel.org/r/20201110190329.11920-1-gerald.schaefer@linux.ibm.com
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
btrfs: cleanup cow block on error 2020-12-11T12:36:46+00:00 Josef Bacik josef@toxicpanda.com 2020-09-29T12:53:54+00:00 49fa7c5eb121c4e0bceebc5bf27102c2a8cfdb44 commit 572c83acdcdafeb04e70aa46be1fa539310be20c upstream. In fstest btrfs/064 a transaction abort in __btrfs_cow_block could lead to a system lockup. It gets stuck trying to write back inodes, and the write back thread was trying to lock an extent buffer: $ cat /proc/2143497/stack [<0>] __btrfs_tree_lock+0x108/0x250 [<0>] lock_extent_buffer_for_io+0x35e/0x3a0 [<0>] btree_write_cache_pages+0x15a/0x3b0 [<0>] do_writepages+0x28/0xb0 [<0>] __writeback_single_inode+0x54/0x5c0 [<0>] writeback_sb_inodes+0x1e8/0x510 [<0>] wb_writeback+0xcc/0x440 [<0>] wb_workfn+0xd7/0x650 [<0>] process_one_work+0x236/0x560 [<0>] worker_thread+0x55/0x3c0 [<0>] kthread+0x13a/0x150 [<0>] ret_from_fork+0x1f/0x30 This is because we got an error while COWing a block, specifically here if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) { ret = btrfs_reloc_cow_block(trans, root, buf, cow); if (ret) { btrfs_abort_transaction(trans, ret); return ret; } } [16402.241552] BTRFS: Transaction aborted (error -2) [16402.242362] WARNING: CPU: 1 PID: 2563188 at fs/btrfs/ctree.c:1074 __btrfs_cow_block+0x376/0x540 [16402.249469] CPU: 1 PID: 2563188 Comm: fsstress Not tainted 5.9.0-rc6+ #8 [16402.249936] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 [16402.250525] RIP: 0010:__btrfs_cow_block+0x376/0x540 [16402.252417] RSP: 0018:ffff9cca40e578b0 EFLAGS: 00010282 [16402.252787] RAX: 0000000000000025 RBX: 0000000000000002 RCX: ffff9132bbd19388 [16402.253278] RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI: ffff9132bbd19380 [16402.254063] RBP: ffff9132b41a49c0 R08: 0000000000000000 R09: 0000000000000000 [16402.254887] R10: 0000000000000000 R11: ffff91324758b080 R12: ffff91326ef17ce0 [16402.255694] R13: ffff91325fc0f000 R14: ffff91326ef176b0 R15: ffff9132815e2000 [16402.256321] FS: 00007f542c6d7b80(0000) GS:ffff9132bbd00000(0000) knlGS:0000000000000000 [16402.256973] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [16402.257374] CR2: 00007f127b83f250 CR3: 0000000133480002 CR4: 0000000000370ee0 [16402.257867] Call Trace: [16402.258072] btrfs_cow_block+0x109/0x230 [16402.258356] btrfs_search_slot+0x530/0x9d0 [16402.258655] btrfs_lookup_file_extent+0x37/0x40 [16402.259155] __btrfs_drop_extents+0x13c/0xd60 [16402.259628] ? btrfs_block_rsv_migrate+0x4f/0xb0 [16402.259949] btrfs_replace_file_extents+0x190/0x820 [16402.260873] btrfs_clone+0x9ae/0xc00 [16402.261139] btrfs_extent_same_range+0x66/0x90 [16402.261771] btrfs_remap_file_range+0x353/0x3b1 [16402.262333] vfs_dedupe_file_range_one.part.0+0xd5/0x140 [16402.262821] vfs_dedupe_file_range+0x189/0x220 [16402.263150] do_vfs_ioctl+0x552/0x700 [16402.263662] __x64_sys_ioctl+0x62/0xb0 [16402.264023] do_syscall_64+0x33/0x40 [16402.264364] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [16402.264862] RIP: 0033:0x7f542c7d15cb [16402.266901] RSP: 002b:00007ffd35944ea8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 [16402.267627] RAX: ffffffffffffffda RBX: 00000000009d1968 RCX: 00007f542c7d15cb [16402.268298] RDX: 00000000009d2490 RSI: 00000000c0189436 RDI: 0000000000000003 [16402.268958] RBP: 00000000009d2520 R08: 0000000000000036 R09: 00000000009d2e64 [16402.269726] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002 [16402.270659] R13: 000000000001f000 R14: 00000000009d1970 R15: 00000000009d2e80 [16402.271498] irq event stamp: 0 [16402.271846] hardirqs last enabled at (0): [<0000000000000000>] 0x0 [16402.272497] hardirqs last disabled at (0): [<ffffffff910dbf59>] copy_process+0x6b9/0x1ba0 [16402.273343] softirqs last enabled at (0): [<ffffffff910dbf59>] copy_process+0x6b9/0x1ba0 [16402.273905] softirqs last disabled at (0): [<0000000000000000>] 0x0 [16402.274338] ---[ end trace 737874a5a41a8236 ]--- [16402.274669] BTRFS: error (device dm-9) in __btrfs_cow_block:1074: errno=-2 No such entry [16402.276179] BTRFS info (device dm-9): forced readonly [16402.277046] BTRFS: error (device dm-9) in btrfs_replace_file_extents:2723: errno=-2 No such entry [16402.278744] BTRFS: error (device dm-9) in __btrfs_cow_block:1074: errno=-2 No such entry [16402.279968] BTRFS: error (device dm-9) in __btrfs_cow_block:1074: errno=-2 No such entry [16402.280582] BTRFS info (device dm-9): balance: ended with status: -30 The problem here is that as soon as we allocate the new block it is locked and marked dirty in the btree inode. This means that we could attempt to writeback this block and need to lock the extent buffer. However we're not unlocking it here and thus we deadlock. Fix this by unlocking the cow block if we have any errors inside of __btrfs_cow_block, and also free it so we do not leak it. CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> [sudip: use old btrfs_abort_transaction()] Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 572c83acdcdafeb04e70aa46be1fa539310be20c upstream.

In fstest btrfs/064 a transaction abort in __btrfs_cow_block could lead
to a system lockup. It gets stuck trying to write back inodes, and the
write back thread was trying to lock an extent buffer:

  $ cat /proc/2143497/stack
  [<0>] __btrfs_tree_lock+0x108/0x250
  [<0>] lock_extent_buffer_for_io+0x35e/0x3a0
  [<0>] btree_write_cache_pages+0x15a/0x3b0
  [<0>] do_writepages+0x28/0xb0
  [<0>] __writeback_single_inode+0x54/0x5c0
  [<0>] writeback_sb_inodes+0x1e8/0x510
  [<0>] wb_writeback+0xcc/0x440
  [<0>] wb_workfn+0xd7/0x650
  [<0>] process_one_work+0x236/0x560
  [<0>] worker_thread+0x55/0x3c0
  [<0>] kthread+0x13a/0x150
  [<0>] ret_from_fork+0x1f/0x30

This is because we got an error while COWing a block, specifically here

        if (test_bit(BTRFS_ROOT_SHAREABLE, &root->state)) {
                ret = btrfs_reloc_cow_block(trans, root, buf, cow);
                if (ret) {
                        btrfs_abort_transaction(trans, ret);
                        return ret;
                }
        }

  [16402.241552] BTRFS: Transaction aborted (error -2)
  [16402.242362] WARNING: CPU: 1 PID: 2563188 at fs/btrfs/ctree.c:1074 __btrfs_cow_block+0x376/0x540
  [16402.249469] CPU: 1 PID: 2563188 Comm: fsstress Not tainted 5.9.0-rc6+ #8
  [16402.249936] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014
  [16402.250525] RIP: 0010:__btrfs_cow_block+0x376/0x540
  [16402.252417] RSP: 0018:ffff9cca40e578b0 EFLAGS: 00010282
  [16402.252787] RAX: 0000000000000025 RBX: 0000000000000002 RCX: ffff9132bbd19388
  [16402.253278] RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI: ffff9132bbd19380
  [16402.254063] RBP: ffff9132b41a49c0 R08: 0000000000000000 R09: 0000000000000000
  [16402.254887] R10: 0000000000000000 R11: ffff91324758b080 R12: ffff91326ef17ce0
  [16402.255694] R13: ffff91325fc0f000 R14: ffff91326ef176b0 R15: ffff9132815e2000
  [16402.256321] FS:  00007f542c6d7b80(0000) GS:ffff9132bbd00000(0000) knlGS:0000000000000000
  [16402.256973] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [16402.257374] CR2: 00007f127b83f250 CR3: 0000000133480002 CR4: 0000000000370ee0
  [16402.257867] Call Trace:
  [16402.258072]  btrfs_cow_block+0x109/0x230
  [16402.258356]  btrfs_search_slot+0x530/0x9d0
  [16402.258655]  btrfs_lookup_file_extent+0x37/0x40
  [16402.259155]  __btrfs_drop_extents+0x13c/0xd60
  [16402.259628]  ? btrfs_block_rsv_migrate+0x4f/0xb0
  [16402.259949]  btrfs_replace_file_extents+0x190/0x820
  [16402.260873]  btrfs_clone+0x9ae/0xc00
  [16402.261139]  btrfs_extent_same_range+0x66/0x90
  [16402.261771]  btrfs_remap_file_range+0x353/0x3b1
  [16402.262333]  vfs_dedupe_file_range_one.part.0+0xd5/0x140
  [16402.262821]  vfs_dedupe_file_range+0x189/0x220
  [16402.263150]  do_vfs_ioctl+0x552/0x700
  [16402.263662]  __x64_sys_ioctl+0x62/0xb0
  [16402.264023]  do_syscall_64+0x33/0x40
  [16402.264364]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
  [16402.264862] RIP: 0033:0x7f542c7d15cb
  [16402.266901] RSP: 002b:00007ffd35944ea8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
  [16402.267627] RAX: ffffffffffffffda RBX: 00000000009d1968 RCX: 00007f542c7d15cb
  [16402.268298] RDX: 00000000009d2490 RSI: 00000000c0189436 RDI: 0000000000000003
  [16402.268958] RBP: 00000000009d2520 R08: 0000000000000036 R09: 00000000009d2e64
  [16402.269726] R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000002
  [16402.270659] R13: 000000000001f000 R14: 00000000009d1970 R15: 00000000009d2e80
  [16402.271498] irq event stamp: 0
  [16402.271846] hardirqs last  enabled at (0): [<0000000000000000>] 0x0
  [16402.272497] hardirqs last disabled at (0): [<ffffffff910dbf59>] copy_process+0x6b9/0x1ba0
  [16402.273343] softirqs last  enabled at (0): [<ffffffff910dbf59>] copy_process+0x6b9/0x1ba0
  [16402.273905] softirqs last disabled at (0): [<0000000000000000>] 0x0
  [16402.274338] ---[ end trace 737874a5a41a8236 ]---
  [16402.274669] BTRFS: error (device dm-9) in __btrfs_cow_block:1074: errno=-2 No such entry
  [16402.276179] BTRFS info (device dm-9): forced readonly
  [16402.277046] BTRFS: error (device dm-9) in btrfs_replace_file_extents:2723: errno=-2 No such entry
  [16402.278744] BTRFS: error (device dm-9) in __btrfs_cow_block:1074: errno=-2 No such entry
  [16402.279968] BTRFS: error (device dm-9) in __btrfs_cow_block:1074: errno=-2 No such entry
  [16402.280582] BTRFS info (device dm-9): balance: ended with status: -30

The problem here is that as soon as we allocate the new block it is
locked and marked dirty in the btree inode.  This means that we could
attempt to writeback this block and need to lock the extent buffer.
However we're not unlocking it here and thus we deadlock.

Fix this by unlocking the cow block if we have any errors inside of
__btrfs_cow_block, and also free it so we do not leak it.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
[sudip: use old btrfs_abort_transaction()]
Signed-off-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tracing: Fix userstacktrace option for instances 2020-12-11T12:36:46+00:00 Steven Rostedt (VMware) rostedt@goodmis.org 2020-12-04T21:36:16+00:00 bb8ebd2b89a4397c96b8510d0f356492326f9449 commit bcee5278958802b40ee8b26679155a6d9231783e upstream. When the instances were able to use their own options, the userstacktrace option was left hardcoded for the top level. This made the instance userstacktrace option bascially into a nop, and will confuse users that set it, but nothing happens (I was confused when it happened to me!) Cc: stable@vger.kernel.org Fixes: 16270145ce6b ("tracing: Add trace options for core options to instances") Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit bcee5278958802b40ee8b26679155a6d9231783e upstream.

When the instances were able to use their own options, the userstacktrace
option was left hardcoded for the top level. This made the instance
userstacktrace option bascially into a nop, and will confuse users that set
it, but nothing happens (I was confused when it happened to me!)

Cc: stable@vger.kernel.org
Fixes: 16270145ce6b ("tracing: Add trace options for core options to instances")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
spi: bcm2835: Release the DMA channel if probe fails after dma_init 2020-12-11T12:36:46+00:00 Peter Ujfalusi peter.ujfalusi@ti.com 2020-12-06T12:53:03+00:00 543327b007f34da28a996c3dd526f5508ee86a68 [ Upstream commit 666224b43b4bd4612ce3b758c038f9bc5c5e3fcb ] The DMA channel was not released if either devm_request_irq() or devm_spi_register_controller() failed. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com> Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> Link: https://lore.kernel.org/r/20191212135550.4634-3-peter.ujfalusi@ti.com Signed-off-by: Mark Brown <broonie@kernel.org> [lukas: backport to 4.19-stable] Signed-off-by: Lukas Wunner <lukas@wunner.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 666224b43b4bd4612ce3b758c038f9bc5c5e3fcb ]

The DMA channel was not released if either devm_request_irq() or
devm_spi_register_controller() failed.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Link: https://lore.kernel.org/r/20191212135550.4634-3-peter.ujfalusi@ti.com
Signed-off-by: Mark Brown <broonie@kernel.org>
[lukas: backport to 4.19-stable]
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
spi: bcm2835: Fix use-after-free on unbind 2020-12-11T12:36:46+00:00 Lukas Wunner lukas@wunner.de 2020-12-06T12:53:01+00:00 0713aa02f20d8cbd5961b47a489c9aa24c1b4ec4 [ Upstream commit e1483ac030fb4c57734289742f1c1d38dca61e22 ] bcm2835_spi_remove() accesses the driver's private data after calling spi_unregister_controller() even though that function releases the last reference on the spi_controller and thereby frees the private data. Fix by switching over to the new devm_spi_alloc_master() helper which keeps the private data accessible until the driver has unbound. Fixes: f8043872e796 ("spi: add driver for BCM2835") Reported-by: Sascha Hauer <s.hauer@pengutronix.de> Reported-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Lukas Wunner <lukas@wunner.de> Cc: <stable@vger.kernel.org> # v3.10+: 5e844cc37a5c: spi: Introduce device-managed SPI controller allocation Cc: <stable@vger.kernel.org> # v3.10+ Cc: Vladimir Oltean <olteanv@gmail.com> Tested-by: Florian Fainelli <f.fainelli@gmail.com> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Link: https://lore.kernel.org/r/ad66e0a0ad96feb848814842ecf5b6a4539ef35c.1605121038.git.lukas@wunner.de Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit e1483ac030fb4c57734289742f1c1d38dca61e22 ]

bcm2835_spi_remove() accesses the driver's private data after calling
spi_unregister_controller() even though that function releases the last
reference on the spi_controller and thereby frees the private data.

Fix by switching over to the new devm_spi_alloc_master() helper which
keeps the private data accessible until the driver has unbound.

Fixes: f8043872e796 ("spi: add driver for BCM2835")
Reported-by: Sascha Hauer <s.hauer@pengutronix.de>
Reported-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Lukas Wunner <lukas@wunner.de>
Cc: <stable@vger.kernel.org> # v3.10+: 5e844cc37a5c: spi: Introduce device-managed SPI controller allocation
Cc: <stable@vger.kernel.org> # v3.10+
Cc: Vladimir Oltean <olteanv@gmail.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/ad66e0a0ad96feb848814842ecf5b6a4539ef35c.1605121038.git.lukas@wunner.de
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
spi: Introduce device-managed SPI controller allocation 2020-12-11T12:36:45+00:00 Lukas Wunner lukas@wunner.de 2020-12-06T12:53:00+00:00 a4add022c1552b0d51a0b89a4781919d6ebac4f9 [ Upstream commit 5e844cc37a5cbaa460e68f9a989d321d63088a89 ] SPI driver probing currently comprises two steps, whereas removal comprises only one step: spi_alloc_master() spi_register_master() spi_unregister_master() That's because spi_unregister_master() calls device_unregister() instead of device_del(), thereby releasing the reference on the spi_master which was obtained by spi_alloc_master(). An SPI driver's private data is contained in the same memory allocation as the spi_master struct. Thus, once spi_unregister_master() has been called, the private data is inaccessible. But some drivers need to access it after spi_unregister_master() to perform further teardown steps. Introduce devm_spi_alloc_master(), which releases a reference on the spi_master struct only after the driver has unbound, thereby keeping the memory allocation accessible. Change spi_unregister_master() to not release a reference if the spi_master was allocated by the new devm function. The present commit is small enough to be backportable to stable. It allows fixing drivers which use the private data in their ->remove() hook after it's been freed. It also allows fixing drivers which neglect to release a reference on the spi_master in the probe error path. Long-term, most SPI drivers shall be moved over to the devm function introduced herein. The few that can't shall be changed in a treewide commit to explicitly release the last reference on the master. That commit shall amend spi_unregister_master() to no longer release a reference, thereby completing the migration. As a result, the behaviour will be less surprising and more consistent with subsystems such as IIO, which also includes the private data in the allocation of the generic iio_dev struct, but calls device_del() in iio_device_unregister(). Signed-off-by: Lukas Wunner <lukas@wunner.de> Link: https://lore.kernel.org/r/272bae2ef08abd21388c98e23729886663d19192.1605121038.git.lukas@wunner.de Signed-off-by: Mark Brown <broonie@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 5e844cc37a5cbaa460e68f9a989d321d63088a89 ]

SPI driver probing currently comprises two steps, whereas removal
comprises only one step:

    spi_alloc_master()
    spi_register_master()

    spi_unregister_master()

That's because spi_unregister_master() calls device_unregister()
instead of device_del(), thereby releasing the reference on the
spi_master which was obtained by spi_alloc_master().

An SPI driver's private data is contained in the same memory allocation
as the spi_master struct.  Thus, once spi_unregister_master() has been
called, the private data is inaccessible.  But some drivers need to
access it after spi_unregister_master() to perform further teardown
steps.

Introduce devm_spi_alloc_master(), which releases a reference on the
spi_master struct only after the driver has unbound, thereby keeping the
memory allocation accessible.  Change spi_unregister_master() to not
release a reference if the spi_master was allocated by the new devm
function.

The present commit is small enough to be backportable to stable.
It allows fixing drivers which use the private data in their ->remove()
hook after it's been freed.  It also allows fixing drivers which neglect
to release a reference on the spi_master in the probe error path.

Long-term, most SPI drivers shall be moved over to the devm function
introduced herein.  The few that can't shall be changed in a treewide
commit to explicitly release the last reference on the master.
That commit shall amend spi_unregister_master() to no longer release
a reference, thereby completing the migration.

As a result, the behaviour will be less surprising and more consistent
with subsystems such as IIO, which also includes the private data in the
allocation of the generic iio_dev struct, but calls device_del() in
iio_device_unregister().

Signed-off-by: Lukas Wunner <lukas@wunner.de>
Link: https://lore.kernel.org/r/272bae2ef08abd21388c98e23729886663d19192.1605121038.git.lukas@wunner.de
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>