[syzbot] [dri?] possible deadlock in drm_mode_get_lease_ioctl

From: syzbot
Date: Thu Dec 05 2024 - 10:04:20 EST

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Hello,

syzbot found the following issue on:

HEAD commit: 7b1d1d4cfac0 Merge remote-tracking branch 'iommu/arm/smmu'..
git tree: git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci
console output: https://syzkaller.appspot.com/x/log.txt?x=1186dd30580000
kernel config: https://syzkaller.appspot.com/x/.config?x=9bc44a6de1ceb5d6
dashboard link: https://syzkaller.appspot.com/bug?extid=969eb4c3dd28b1dc507a
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
userspace arch: arm64

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/4d4a0162c7c3/disk-7b1d1d4c.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/a8c47a4be472/vmlinux-7b1d1d4c.xz
kernel image: https://storage.googleapis.com/syzbot-assets/0e173b91f83e/Image-7b1d1d4c.gz.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+969eb4c3dd28b1dc507a@xxxxxxxxxxxxxxxxxxxxxxxxx

======================================================
WARNING: possible circular locking dependency detected
6.12.0-syzkaller-g7b1d1d4cfac0 #0 Not tainted
------------------------------------------------------
syz.3.235/8073 is trying to acquire lock:
ffff0000dba0e188 (&mm->mmap_lock){++++}-{3:3}, at: __might_fault+0x9c/0x124 mm/memory.c:6715

but task is already holding lock:
ffff0000c9c4c5d0 (&dev->mode_config.idr_mutex){+.+.}-{3:3}, at: drm_mode_get_lease_ioctl+0x1ec/0x63c drivers/gpu/drm/drm_lease.c:660

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #6 (&dev->mode_config.idr_mutex){+.+.}-{3:3}:
__mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:608
__mutex_lock kernel/locking/mutex.c:752 [inline]
mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:804
__drm_mode_object_add+0xb8/0x204 drivers/gpu/drm/drm_mode_object.c:47
drm_framebuffer_init+0x104/0x24c drivers/gpu/drm/drm_framebuffer.c:873
drm_gem_fb_init drivers/gpu/drm/drm_gem_framebuffer_helper.c:82 [inline]
drm_gem_fb_init_with_funcs+0x9bc/0xd64 drivers/gpu/drm/drm_gem_framebuffer_helper.c:202
drm_gem_fb_create_with_funcs drivers/gpu/drm/drm_gem_framebuffer_helper.c:245 [inline]
drm_gem_fb_create+0x84/0xd4 drivers/gpu/drm/drm_gem_framebuffer_helper.c:286
drm_internal_framebuffer_create+0x100c/0x1408 drivers/gpu/drm/drm_framebuffer.c:303
drm_mode_addfb2+0xb4/0x2a8 drivers/gpu/drm/drm_framebuffer.c:337
drm_client_buffer_addfb drivers/gpu/drm/drm_client.c:480 [inline]
drm_client_framebuffer_create+0x38c/0x6cc drivers/gpu/drm/drm_client.c:522
drm_fbdev_shmem_helper_fb_probe+0x1a4/0x728 drivers/gpu/drm/drm_fbdev_shmem.c:126
drm_fb_helper_single_fb_probe drivers/gpu/drm/drm_fb_helper.c:1669 [inline]
__drm_fb_helper_initial_config_and_unlock+0x12e8/0x19a4 drivers/gpu/drm/drm_fb_helper.c:1847
drm_fb_helper_initial_config+0x48/0x64 drivers/gpu/drm/drm_fb_helper.c:1934
drm_fbdev_shmem_client_hotplug+0x158/0x22c drivers/gpu/drm/drm_fbdev_shmem.c:250
drm_client_register+0x144/0x1e0 drivers/gpu/drm/drm_client.c:141
drm_fbdev_shmem_setup+0x11c/0x2cc drivers/gpu/drm/drm_fbdev_shmem.c:309
vkms_create drivers/gpu/drm/vkms/vkms_drv.c:228 [inline]
vkms_init+0x4f0/0x600 drivers/gpu/drm/vkms/vkms_drv.c:254
do_one_initcall+0x24c/0x9c0 init/main.c:1269
do_initcall_level+0x154/0x214 init/main.c:1331
do_initcalls+0x58/0xac init/main.c:1347
do_basic_setup+0x8c/0xa0 init/main.c:1366
kernel_init_freeable+0x324/0x478 init/main.c:1580
kernel_init+0x24/0x2a0 init/main.c:1469
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:862

-> #5 (&helper->lock){+.+.}-{3:3}:
__mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:608
__mutex_lock kernel/locking/mutex.c:752 [inline]
mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:804
__drm_fb_helper_restore_fbdev_mode_unlocked+0xb4/0x178 drivers/gpu/drm/drm_fb_helper.c:228
drm_fb_helper_set_par+0xc4/0x110 drivers/gpu/drm/drm_fb_helper.c:1345
fbcon_init+0xf34/0x1eb8 drivers/video/fbdev/core/fbcon.c:1113
visual_init+0x27c/0x548 drivers/tty/vt/vt.c:1011
do_bind_con_driver+0x7dc/0xe04 drivers/tty/vt/vt.c:3833
do_take_over_console+0x4ac/0x5f0 drivers/tty/vt/vt.c:4399
do_fbcon_takeover+0x158/0x260 drivers/video/fbdev/core/fbcon.c:549
do_fb_registered drivers/video/fbdev/core/fbcon.c:2988 [inline]
fbcon_fb_registered+0x370/0x4ec drivers/video/fbdev/core/fbcon.c:3008
do_register_framebuffer drivers/video/fbdev/core/fbmem.c:449 [inline]
register_framebuffer+0x470/0x610 drivers/video/fbdev/core/fbmem.c:515
__drm_fb_helper_initial_config_and_unlock+0x13b0/0x19a4 drivers/gpu/drm/drm_fb_helper.c:1869
drm_fb_helper_initial_config+0x48/0x64 drivers/gpu/drm/drm_fb_helper.c:1934
drm_fbdev_shmem_client_hotplug+0x158/0x22c drivers/gpu/drm/drm_fbdev_shmem.c:250
drm_client_register+0x144/0x1e0 drivers/gpu/drm/drm_client.c:141
drm_fbdev_shmem_setup+0x11c/0x2cc drivers/gpu/drm/drm_fbdev_shmem.c:309
vkms_create drivers/gpu/drm/vkms/vkms_drv.c:228 [inline]
vkms_init+0x4f0/0x600 drivers/gpu/drm/vkms/vkms_drv.c:254
do_one_initcall+0x24c/0x9c0 init/main.c:1269
do_initcall_level+0x154/0x214 init/main.c:1331
do_initcalls+0x58/0xac init/main.c:1347
do_basic_setup+0x8c/0xa0 init/main.c:1366
kernel_init_freeable+0x324/0x478 init/main.c:1580
kernel_init+0x24/0x2a0 init/main.c:1469
ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:862

-> #4 (console_lock){+.+.}-{0:0}:
console_lock+0x19c/0x1f4 kernel/printk/printk.c:2808
__bch2_print_string_as_lines fs/bcachefs/util.c:267 [inline]
bch2_print_string_as_lines+0x2c/0xd4 fs/bcachefs/util.c:286
__bch2_fsck_err+0x1864/0x2544 fs/bcachefs/error.c:411
bch2_check_fix_ptr fs/bcachefs/buckets.c:112 [inline]
bch2_check_fix_ptrs+0x15b8/0x515c fs/bcachefs/buckets.c:266
bch2_trigger_extent+0x71c/0x814 fs/bcachefs/buckets.c:856
bch2_key_trigger fs/bcachefs/bkey_methods.h:87 [inline]
bch2_gc_mark_key+0x4b4/0xb70 fs/bcachefs/btree_gc.c:634
bch2_gc_btree fs/bcachefs/btree_gc.c:670 [inline]
bch2_gc_btrees fs/bcachefs/btree_gc.c:729 [inline]
bch2_check_allocations+0x1018/0x48f4 fs/bcachefs/btree_gc.c:1133
bch2_run_recovery_pass+0xe4/0x1d4 fs/bcachefs/recovery_passes.c:191
bch2_run_recovery_passes+0x30c/0x73c fs/bcachefs/recovery_passes.c:244
bch2_fs_recovery+0x32d8/0x55dc fs/bcachefs/recovery.c:861
bch2_fs_start+0x30c/0x53c fs/bcachefs/super.c:1037
bch2_fs_get_tree+0x938/0x1030 fs/bcachefs/fs.c:2170
vfs_get_tree+0x90/0x28c fs/super.c:1814
do_new_mount+0x278/0x900 fs/namespace.c:3507
path_mount+0x590/0xe04 fs/namespace.c:3834
do_mount fs/namespace.c:3847 [inline]
__do_sys_mount fs/namespace.c:4057 [inline]
__se_sys_mount fs/namespace.c:4034 [inline]
__arm64_sys_mount+0x4d4/0x5ac fs/namespace.c:4034
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

-> #3 (&c->fsck_error_msgs_lock){+.+.}-{3:3}:
__mutex_lock_common+0x190/0x21a0 kernel/locking/mutex.c:608
__mutex_lock kernel/locking/mutex.c:752 [inline]
mutex_lock_nested+0x2c/0x38 kernel/locking/mutex.c:804
__bch2_fsck_err+0x344/0x2544 fs/bcachefs/error.c:282
bch2_check_fix_ptr fs/bcachefs/buckets.c:112 [inline]
bch2_check_fix_ptrs+0x15b8/0x515c fs/bcachefs/buckets.c:266
bch2_trigger_extent+0x71c/0x814 fs/bcachefs/buckets.c:856
bch2_key_trigger fs/bcachefs/bkey_methods.h:87 [inline]
bch2_gc_mark_key+0x4b4/0xb70 fs/bcachefs/btree_gc.c:634
bch2_gc_btree fs/bcachefs/btree_gc.c:670 [inline]
bch2_gc_btrees fs/bcachefs/btree_gc.c:729 [inline]
bch2_check_allocations+0x1018/0x48f4 fs/bcachefs/btree_gc.c:1133
bch2_run_recovery_pass+0xe4/0x1d4 fs/bcachefs/recovery_passes.c:191
bch2_run_recovery_passes+0x30c/0x73c fs/bcachefs/recovery_passes.c:244
bch2_fs_recovery+0x32d8/0x55dc fs/bcachefs/recovery.c:861
bch2_fs_start+0x30c/0x53c fs/bcachefs/super.c:1037
bch2_fs_get_tree+0x938/0x1030 fs/bcachefs/fs.c:2170
vfs_get_tree+0x90/0x28c fs/super.c:1814
do_new_mount+0x278/0x900 fs/namespace.c:3507
path_mount+0x590/0xe04 fs/namespace.c:3834
do_mount fs/namespace.c:3847 [inline]
__do_sys_mount fs/namespace.c:4057 [inline]
__se_sys_mount fs/namespace.c:4034 [inline]
__arm64_sys_mount+0x4d4/0x5ac fs/namespace.c:4034
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

-> #2 (&c->mark_lock){++++}-{0:0}:
percpu_down_read+0x5c/0x2e8 include/linux/percpu-rwsem.h:51
__bch2_disk_reservation_add+0xc4/0x9f4 fs/bcachefs/buckets.c:1170
bch2_disk_reservation_add+0x29c/0x4f4 fs/bcachefs/buckets.h:367
__bch2_folio_reservation_get+0x2dc/0x798 fs/bcachefs/fs-io-pagecache.c:428
bch2_folio_reservation_get fs/bcachefs/fs-io-pagecache.c:477 [inline]
bch2_page_mkwrite+0xa70/0xe44 fs/bcachefs/fs-io-pagecache.c:637
do_page_mkwrite+0x140/0x2dc mm/memory.c:3162
do_shared_fault mm/memory.c:5373 [inline]
do_fault mm/memory.c:5435 [inline]
do_pte_missing mm/memory.c:3965 [inline]
handle_pte_fault mm/memory.c:5766 [inline]
__handle_mm_fault+0x1e1c/0x66e8 mm/memory.c:5909
handle_mm_fault+0x29c/0x8b4 mm/memory.c:6077
do_page_fault+0x570/0x10a8 arch/arm64/mm/fault.c:690
do_translation_fault+0xc4/0x114 arch/arm64/mm/fault.c:783
do_mem_abort+0x74/0x200 arch/arm64/mm/fault.c:919
el0_da+0x60/0x178 arch/arm64/kernel/entry-common.c:604
el0t_64_sync_handler+0xcc/0x108 arch/arm64/kernel/entry-common.c:765
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

-> #1 (sb_pagefaults#2){.+.+}-{0:0}:
percpu_down_read include/linux/percpu-rwsem.h:51 [inline]
__sb_start_write include/linux/fs.h:1716 [inline]
sb_start_pagefault include/linux/fs.h:1881 [inline]
bch2_page_mkwrite+0x280/0xe44 fs/bcachefs/fs-io-pagecache.c:614
do_page_mkwrite+0x140/0x2dc mm/memory.c:3162
do_shared_fault mm/memory.c:5373 [inline]
do_fault mm/memory.c:5435 [inline]
do_pte_missing mm/memory.c:3965 [inline]
handle_pte_fault mm/memory.c:5766 [inline]
__handle_mm_fault+0x1e1c/0x66e8 mm/memory.c:5909
handle_mm_fault+0x29c/0x8b4 mm/memory.c:6077
do_page_fault+0x570/0x10a8 arch/arm64/mm/fault.c:690
do_translation_fault+0xc4/0x114 arch/arm64/mm/fault.c:783
do_mem_abort+0x74/0x200 arch/arm64/mm/fault.c:919
el0_da+0x60/0x178 arch/arm64/kernel/entry-common.c:604
el0t_64_sync_handler+0xcc/0x108 arch/arm64/kernel/entry-common.c:765
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

-> #0 (&mm->mmap_lock){++++}-{3:3}:
check_prev_add kernel/locking/lockdep.c:3161 [inline]
check_prevs_add kernel/locking/lockdep.c:3280 [inline]
validate_chain kernel/locking/lockdep.c:3904 [inline]
__lock_acquire+0x33f8/0x77c8 kernel/locking/lockdep.c:5202
lock_acquire+0x240/0x728 kernel/locking/lockdep.c:5825
__might_fault+0xc4/0x124 mm/memory.c:6716
drm_mode_get_lease_ioctl+0x318/0x63c drivers/gpu/drm/drm_lease.c:673
drm_ioctl_kernel+0x26c/0x368 drivers/gpu/drm/drm_ioctl.c:745
drm_ioctl+0x624/0xb14 drivers/gpu/drm/drm_ioctl.c:842
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl fs/ioctl.c:893 [inline]
__arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:893
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

other info that might help us debug this:

Chain exists of:
&mm->mmap_lock --> &helper->lock --> &dev->mode_config.idr_mutex

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(&dev->mode_config.idr_mutex);
lock(&helper->lock);
lock(&dev->mode_config.idr_mutex);
rlock(&mm->mmap_lock);

*** DEADLOCK ***

1 lock held by syz.3.235/8073:
#0: ffff0000c9c4c5d0 (&dev->mode_config.idr_mutex){+.+.}-{3:3}, at: drm_mode_get_lease_ioctl+0x1ec/0x63c drivers/gpu/drm/drm_lease.c:660

stack backtrace:
CPU: 1 UID: 0 PID: 8073 Comm: syz.3.235 Not tainted 6.12.0-syzkaller-g7b1d1d4cfac0 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call trace:
show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:484 (C)
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:120
dump_stack+0x1c/0x28 lib/dump_stack.c:129
print_circular_bug+0x154/0x1c0 kernel/locking/lockdep.c:2074
check_noncircular+0x310/0x404 kernel/locking/lockdep.c:2206
check_prev_add kernel/locking/lockdep.c:3161 [inline]
check_prevs_add kernel/locking/lockdep.c:3280 [inline]
validate_chain kernel/locking/lockdep.c:3904 [inline]
__lock_acquire+0x33f8/0x77c8 kernel/locking/lockdep.c:5202
lock_acquire+0x240/0x728 kernel/locking/lockdep.c:5825
__might_fault+0xc4/0x124 mm/memory.c:6716
drm_mode_get_lease_ioctl+0x318/0x63c drivers/gpu/drm/drm_lease.c:673
drm_ioctl_kernel+0x26c/0x368 drivers/gpu/drm/drm_ioctl.c:745
drm_ioctl+0x624/0xb14 drivers/gpu/drm/drm_ioctl.c:842
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:907 [inline]
__se_sys_ioctl fs/ioctl.c:893 [inline]
__arm64_sys_ioctl+0x14c/0x1c8 fs/ioctl.c:893
__invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
invoke_syscall+0x98/0x2b8 arch/arm64/kernel/syscall.c:49
el0_svc_common+0x130/0x23c arch/arm64/kernel/syscall.c:132
do_el0_svc+0x48/0x58 arch/arm64/kernel/syscall.c:151
el0_svc+0x54/0x168 arch/arm64/kernel/entry-common.c:744
el0t_64_sync_handler+0x84/0x108 arch/arm64/kernel/entry-common.c:762
el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:600

---
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Next message: Ard Biesheuvel: "[PATCH v2 3/6] arm64/kvm: Configure HYP TCR.PS/DS based on host stage1"
Previous message: Ard Biesheuvel: "[PATCH v2 0/6] arm64: Clean up and simplify PA space size handling"
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