From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-il1-f198.google.com (mail-il1-f198.google.com [209.85.166.198]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C597D372 for ; Tue, 26 Nov 2024 00:01:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.166.198 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732579290; cv=none; b=uF15+EFszsuOSCB4GVR5bXoEafNcEmPGF+3It9qJnAaiRmpx1US86UjqvIubCOy7STmJEBGnqyp3UrRYPp7eujxk6k99OzT3J301BrdWX/Waj2lyeMq7wfgVdu2bGEdLvwwk6gZN5Cti7gu6ZLQWRuZ/uFNDWwhfJ9jA/2EG9fk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1732579290; c=relaxed/simple; bh=DK2bV5jFCXcVjvyuFnimur+ALEOOVu406+lRCd4tw/s=; h=MIME-Version:Date:Message-ID:Subject:From:To:Content-Type; b=pRAs6IehhR25a6ExVtYwRU6tYcmasfZN0EIa3yn5HIibvMx7zhepJx+E6GoGDZD3znqcXnz/iIlE8pK/w42tGyjTS79iIMeNjLzNzNPr4INC+j4j9QYkecl/glCUYjvcJ5kyEJ68f3xNh/bzE1cJ2GfDinvXEY+p9+gbgnK+Uug= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.166.198 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-il1-f198.google.com with SMTP id e9e14a558f8ab-3a77fad574cso48930725ab.2 for ; Mon, 25 Nov 2024 16:01:26 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1732579285; x=1733184085; h=to:from:subject:message-id:date:mime-version:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=Jbd5lguwzQQPqL+OCWKYz4u+DtX3IWw44+ww8J1AmPE=; b=vB/hcQmZM+jgWf2evPOe1wbmCYrH5qLyKKV2xPlcvvncDXpvBWDQHA3hPWe/4Qieoy 0l6vlPXqaW2WemZch/4qZbQ6ST4n3eI2I+z+R4kpU3ENYXcwop6zn5DEoRG7UqWzZfQO ndrNJ88XbqzuN7icF448YJRrP8P0ece+d+S5SdpVLztF9KiwvDL9Rz5rBETAEFePt02I RoY8O2tBTzF4og6gQ4oiYs7VleZgy0ySJ5Wwtjr6JQvNBwgAl0let+Z5iHUhNhAaG6OE 5SK7/+Rf/FzvT8kZkkM/AZfav8VJWx3l5J3P1LS8koFs93ZokLoNf4dpO7WZ36keX2NM ZJSw== X-Forwarded-Encrypted: i=1; AJvYcCXDvnvjG9LDum3rJ6yOrIJBMNTfCJ42vlX6hRiuB8UDj8R+B1R9/2lgEKHLW+0CoSBvrYLPtR7JD5XtYLA=@vger.kernel.org X-Gm-Message-State: AOJu0YwEDwJJ+Vtvvdtt0+oh2hXR5LUC45FuttSTJmbKlO6TwcOXptyT 9WnngToQ4OCmdp96AN/fdOanWhdxJppHaF8bCDeRdkp5jTulk5SW2zPgM42h1NRg+G7EwoL9ZAF MeCNmjqLDCAGa9INiiDDHxjdj4XDq35a/8Zof7BpysjnLflsUmjX5sx8= X-Google-Smtp-Source: AGHT+IFsfRw1otpEhtmlwuyfzIiu3jWSMCC6h/EUwsaQP0P4uva1+QjRCWKpvaP50hCNWR0o/XC2+nMAWmpwCcHIuTk9MJyqA22N Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6e02:b21:b0:3a7:6e97:9877 with SMTP id e9e14a558f8ab-3a79af9ed3emr145227765ab.24.1732579285581; Mon, 25 Nov 2024 16:01:25 -0800 (PST) Date: Mon, 25 Nov 2024 16:01:25 -0800 X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <67450fd5.050a0220.1286eb.0009.GAE@google.com> Subject: [syzbot] [bcachefs?] possible deadlock in __bch2_folio_reservation_get From: syzbot To: kent.overstreet@linux.dev, linux-bcachefs@vger.kernel.org, linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" Hello, syzbot found the following issue on: HEAD commit: 43fb83c17ba2 Merge tag 'soc-arm-6.13' of git://git.kernel... git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=10f6a75f980000 kernel config: https://syzkaller.appspot.com/x/.config?x=1638cad79464dac0 dashboard link: https://syzkaller.appspot.com/bug?extid=9784eb115ca16c8cdd1d compiler: gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40 Unfortunately, I don't have any reproducer for this issue yet. Downloadable assets: disk image: https://storage.googleapis.com/syzbot-assets/6b7a3a910252/disk-43fb83c1.raw.xz vmlinux: https://storage.googleapis.com/syzbot-assets/78e328593d54/vmlinux-43fb83c1.xz kernel image: https://storage.googleapis.com/syzbot-assets/3dd5bf3f229a/bzImage-43fb83c1.xz IMPORTANT: if you fix the issue, please add the following tag to the commit: Reported-by: syzbot+9784eb115ca16c8cdd1d@syzkaller.appspotmail.com bcachefs (loop7): going read-write bcachefs (loop7): done starting filesystem ====================================================== WARNING: possible circular locking dependency detected 6.12.0-syzkaller-03657-g43fb83c17ba2 #0 Not tainted ------------------------------------------------------ syz.7.1397/14121 is trying to acquire lock: ffff88803c5049d0 (&c->mark_lock){++++}-{0:0}, at: bch2_disk_reservation_add fs/bcachefs/buckets.h:367 [inline] ffff88803c5049d0 (&c->mark_lock){++++}-{0:0}, at: __bch2_folio_reservation_get+0x8d9/0xab0 fs/bcachefs/fs-io-pagecache.c:428 but task is already holding lock: ffff88802940a518 (sb_pagefaults#5){.+.+}-{0:0}, at: do_page_mkwrite+0x17a/0x380 mm/memory.c:3162 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #8 (sb_pagefaults#5){.+.+}-{0:0}: percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __sb_start_write include/linux/fs.h:1725 [inline] sb_start_pagefault include/linux/fs.h:1890 [inline] bch2_page_mkwrite+0x2ec/0xec0 fs/bcachefs/fs-io-pagecache.c:614 do_page_mkwrite+0x17a/0x380 mm/memory.c:3162 do_shared_fault mm/memory.c:5373 [inline] do_fault mm/memory.c:5435 [inline] do_pte_missing+0x29e/0x3e70 mm/memory.c:3965 handle_pte_fault mm/memory.c:5766 [inline] __handle_mm_fault+0x100a/0x2a10 mm/memory.c:5909 handle_mm_fault+0x3fa/0xaa0 mm/memory.c:6077 do_user_addr_fault+0x7a3/0x13f0 arch/x86/mm/fault.c:1389 handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline] _inline_copy_to_user include/linux/uaccess.h:197 [inline] _copy_to_user+0xb6/0xd0 lib/usercopy.c:26 copy_to_user include/linux/uaccess.h:225 [inline] rng_dev_read+0x1f4/0x800 drivers/char/hw_random/core.c:258 do_loop_readv_writev fs/read_write.c:840 [inline] do_loop_readv_writev fs/read_write.c:828 [inline] vfs_readv+0x6c2/0x890 fs/read_write.c:1013 do_preadv+0x1b1/0x270 fs/read_write.c:1125 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #7 (&mm->mmap_lock){++++}-{4:4}: __might_fault mm/memory.c:6716 [inline] __might_fault+0x11b/0x190 mm/memory.c:6709 drm_mode_atomic_ioctl+0x524/0x25d0 drivers/gpu/drm/drm_atomic_uapi.c:1437 drm_ioctl_kernel+0x1e9/0x3d0 drivers/gpu/drm/drm_ioctl.c:745 drm_ioctl+0x5d6/0xc00 drivers/gpu/drm/drm_ioctl.c:842 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:906 [inline] __se_sys_ioctl fs/ioctl.c:892 [inline] __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:892 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #6 (crtc_ww_class_mutex){+.+.}-{0:0}: ww_acquire_init include/linux/ww_mutex.h:162 [inline] drm_modeset_acquire_init+0x234/0x410 drivers/gpu/drm/drm_modeset_lock.c:250 drmm_mode_config_init+0x10ef/0x1870 drivers/gpu/drm/drm_mode_config.c:453 vkms_modeset_init drivers/gpu/drm/vkms/vkms_drv.c:156 [inline] vkms_create drivers/gpu/drm/vkms/vkms_drv.c:217 [inline] vkms_init+0x3bc/0x760 drivers/gpu/drm/vkms/vkms_drv.c:254 do_one_initcall+0x12b/0x700 init/main.c:1266 do_initcall_level init/main.c:1328 [inline] do_initcalls init/main.c:1344 [inline] do_basic_setup init/main.c:1363 [inline] kernel_init_freeable+0x5c7/0x900 init/main.c:1577 kernel_init+0x1c/0x2b0 init/main.c:1466 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #5 (crtc_ww_class_acquire){+.+.}-{0:0}: ww_acquire_init include/linux/ww_mutex.h:161 [inline] drm_modeset_acquire_init+0x219/0x410 drivers/gpu/drm/drm_modeset_lock.c:250 drm_client_modeset_commit_atomic+0xc9/0x7f0 drivers/gpu/drm/drm_client_modeset.c:1007 drm_client_modeset_commit_locked+0x14d/0x580 drivers/gpu/drm/drm_client_modeset.c:1171 drm_client_modeset_commit+0x4f/0x80 drivers/gpu/drm/drm_client_modeset.c:1197 __drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:237 [inline] __drm_fb_helper_restore_fbdev_mode_unlocked+0x130/0x180 drivers/gpu/drm/drm_fb_helper.c:216 drm_fb_helper_set_par+0xd8/0x120 drivers/gpu/drm/drm_fb_helper.c:1345 fbcon_init+0x883/0x1890 drivers/video/fbdev/core/fbcon.c:1113 visual_init+0x320/0x620 drivers/tty/vt/vt.c:1011 do_bind_con_driver.isra.0+0x57a/0xbf0 drivers/tty/vt/vt.c:3833 do_take_over_console+0x4f4/0x650 drivers/tty/vt/vt.c:4399 do_fbcon_takeover+0xe8/0x210 drivers/video/fbdev/core/fbcon.c:549 do_fb_registered drivers/video/fbdev/core/fbcon.c:2988 [inline] fbcon_fb_registered+0x375/0x6a0 drivers/video/fbdev/core/fbcon.c:3008 do_register_framebuffer+0x466/0x7f0 drivers/video/fbdev/core/fbmem.c:449 register_framebuffer+0x23/0x40 drivers/video/fbdev/core/fbmem.c:515 __drm_fb_helper_initial_config_and_unlock+0xd56/0x1620 drivers/gpu/drm/drm_fb_helper.c:1869 drm_fb_helper_initial_config drivers/gpu/drm/drm_fb_helper.c:1934 [inline] drm_fb_helper_initial_config+0x44/0x60 drivers/gpu/drm/drm_fb_helper.c:1926 drm_fbdev_shmem_client_hotplug+0x1a6/0x280 drivers/gpu/drm/drm_fbdev_shmem.c:250 drm_client_register+0x198/0x280 drivers/gpu/drm/drm_client.c:141 drm_fbdev_shmem_setup+0x184/0x340 drivers/gpu/drm/drm_fbdev_shmem.c:309 vkms_create drivers/gpu/drm/vkms/vkms_drv.c:228 [inline] vkms_init+0x62d/0x760 drivers/gpu/drm/vkms/vkms_drv.c:254 do_one_initcall+0x12b/0x700 init/main.c:1266 do_initcall_level init/main.c:1328 [inline] do_initcalls init/main.c:1344 [inline] do_basic_setup init/main.c:1363 [inline] kernel_init_freeable+0x5c7/0x900 init/main.c:1577 kernel_init+0x1c/0x2b0 init/main.c:1466 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #4 (&client->modeset_mutex){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xa60 kernel/locking/mutex.c:735 drm_client_modeset_probe+0x41a/0x3060 drivers/gpu/drm/drm_client_modeset.c:832 __drm_fb_helper_initial_config_and_unlock+0x131/0x1620 drivers/gpu/drm/drm_fb_helper.c:1846 drm_fb_helper_initial_config drivers/gpu/drm/drm_fb_helper.c:1934 [inline] drm_fb_helper_initial_config+0x44/0x60 drivers/gpu/drm/drm_fb_helper.c:1926 drm_fbdev_shmem_client_hotplug+0x1a6/0x280 drivers/gpu/drm/drm_fbdev_shmem.c:250 drm_client_register+0x198/0x280 drivers/gpu/drm/drm_client.c:141 drm_fbdev_shmem_setup+0x184/0x340 drivers/gpu/drm/drm_fbdev_shmem.c:309 vkms_create drivers/gpu/drm/vkms/vkms_drv.c:228 [inline] vkms_init+0x62d/0x760 drivers/gpu/drm/vkms/vkms_drv.c:254 do_one_initcall+0x12b/0x700 init/main.c:1266 do_initcall_level init/main.c:1328 [inline] do_initcalls init/main.c:1344 [inline] do_basic_setup init/main.c:1363 [inline] kernel_init_freeable+0x5c7/0x900 init/main.c:1577 kernel_init+0x1c/0x2b0 init/main.c:1466 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #3 (&helper->lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xa60 kernel/locking/mutex.c:735 __drm_fb_helper_restore_fbdev_mode_unlocked drivers/gpu/drm/drm_fb_helper.c:228 [inline] __drm_fb_helper_restore_fbdev_mode_unlocked+0xb6/0x180 drivers/gpu/drm/drm_fb_helper.c:216 drm_fb_helper_set_par+0xd8/0x120 drivers/gpu/drm/drm_fb_helper.c:1345 fbcon_init+0x883/0x1890 drivers/video/fbdev/core/fbcon.c:1113 visual_init+0x320/0x620 drivers/tty/vt/vt.c:1011 do_bind_con_driver.isra.0+0x57a/0xbf0 drivers/tty/vt/vt.c:3833 do_take_over_console+0x4f4/0x650 drivers/tty/vt/vt.c:4399 do_fbcon_takeover+0xe8/0x210 drivers/video/fbdev/core/fbcon.c:549 do_fb_registered drivers/video/fbdev/core/fbcon.c:2988 [inline] fbcon_fb_registered+0x375/0x6a0 drivers/video/fbdev/core/fbcon.c:3008 do_register_framebuffer+0x466/0x7f0 drivers/video/fbdev/core/fbmem.c:449 register_framebuffer+0x23/0x40 drivers/video/fbdev/core/fbmem.c:515 __drm_fb_helper_initial_config_and_unlock+0xd56/0x1620 drivers/gpu/drm/drm_fb_helper.c:1869 drm_fb_helper_initial_config drivers/gpu/drm/drm_fb_helper.c:1934 [inline] drm_fb_helper_initial_config+0x44/0x60 drivers/gpu/drm/drm_fb_helper.c:1926 drm_fbdev_shmem_client_hotplug+0x1a6/0x280 drivers/gpu/drm/drm_fbdev_shmem.c:250 drm_client_register+0x198/0x280 drivers/gpu/drm/drm_client.c:141 drm_fbdev_shmem_setup+0x184/0x340 drivers/gpu/drm/drm_fbdev_shmem.c:309 vkms_create drivers/gpu/drm/vkms/vkms_drv.c:228 [inline] vkms_init+0x62d/0x760 drivers/gpu/drm/vkms/vkms_drv.c:254 do_one_initcall+0x12b/0x700 init/main.c:1266 do_initcall_level init/main.c:1328 [inline] do_initcalls init/main.c:1344 [inline] do_basic_setup init/main.c:1363 [inline] kernel_init_freeable+0x5c7/0x900 init/main.c:1577 kernel_init+0x1c/0x2b0 init/main.c:1466 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 -> #2 (console_lock){+.+.}-{0:0}: console_lock+0x7a/0xa0 kernel/printk/printk.c:2833 __bch2_print_string_as_lines+0xeb/0x130 fs/bcachefs/util.c:267 __bch2_fsck_err+0x994/0x1d30 fs/bcachefs/error.c:411 read_btree_roots fs/bcachefs/recovery.c:523 [inline] bch2_fs_recovery+0x2e46/0x4030 fs/bcachefs/recovery.c:853 bch2_fs_start+0x2e9/0x5f0 fs/bcachefs/super.c:1037 bch2_fs_get_tree+0x10db/0x16f0 fs/bcachefs/fs.c:2170 vfs_get_tree+0x92/0x380 fs/super.c:1814 do_new_mount fs/namespace.c:3507 [inline] path_mount+0x14e6/0x1f20 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] __x64_sys_mount+0x294/0x320 fs/namespace.c:4034 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #1 (&c->fsck_error_msgs_lock){+.+.}-{4:4}: __mutex_lock_common kernel/locking/mutex.c:585 [inline] __mutex_lock+0x19b/0xa60 kernel/locking/mutex.c:735 __bch2_fsck_err+0x34c/0x1d30 fs/bcachefs/error.c:282 bch2_check_fix_ptr fs/bcachefs/buckets.c:137 [inline] bch2_check_fix_ptrs+0x1c1e/0x5230 fs/bcachefs/buckets.c:266 bch2_trigger_extent+0x5d0/0x740 fs/bcachefs/buckets.c:856 bch2_key_trigger fs/bcachefs/bkey_methods.h:87 [inline] bch2_gc_mark_key+0x546/0xe30 fs/bcachefs/btree_gc.c:634 bch2_gc_btree.constprop.0+0xe5c/0x1320 fs/bcachefs/btree_gc.c:698 bch2_gc_btrees+0x47c/0xa60 fs/bcachefs/btree_gc.c:729 bch2_check_allocations+0x55a/0xa30 fs/bcachefs/btree_gc.c:1133 bch2_run_recovery_pass+0x91/0x1a0 fs/bcachefs/recovery_passes.c:191 bch2_run_recovery_passes+0x49b/0x780 fs/bcachefs/recovery_passes.c:244 bch2_fs_recovery+0x2358/0x4030 fs/bcachefs/recovery.c:861 bch2_fs_start+0x2e9/0x5f0 fs/bcachefs/super.c:1037 bch2_fs_get_tree+0x10db/0x16f0 fs/bcachefs/fs.c:2170 vfs_get_tree+0x92/0x380 fs/super.c:1814 do_new_mount fs/namespace.c:3507 [inline] path_mount+0x14e6/0x1f20 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] __x64_sys_mount+0x294/0x320 fs/namespace.c:4034 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f -> #0 (&c->mark_lock){++++}-{0:0}: 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+0x249e/0x3c40 kernel/locking/lockdep.c:5226 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __bch2_disk_reservation_add+0xd2/0xd10 fs/bcachefs/buckets.c:1170 bch2_disk_reservation_add fs/bcachefs/buckets.h:367 [inline] __bch2_folio_reservation_get+0x8d9/0xab0 fs/bcachefs/fs-io-pagecache.c:428 bch2_folio_reservation_get fs/bcachefs/fs-io-pagecache.c:477 [inline] bch2_page_mkwrite+0xc4f/0xec0 fs/bcachefs/fs-io-pagecache.c:637 do_page_mkwrite+0x17a/0x380 mm/memory.c:3162 do_shared_fault mm/memory.c:5373 [inline] do_fault mm/memory.c:5435 [inline] do_pte_missing+0x29e/0x3e70 mm/memory.c:3965 handle_pte_fault mm/memory.c:5766 [inline] __handle_mm_fault+0x100a/0x2a10 mm/memory.c:5909 handle_mm_fault+0x3fa/0xaa0 mm/memory.c:6077 do_user_addr_fault+0x7a3/0x13f0 arch/x86/mm/fault.c:1389 handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline] raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline] _inline_copy_to_user include/linux/uaccess.h:197 [inline] _copy_to_user+0xb6/0xd0 lib/usercopy.c:26 copy_to_user include/linux/uaccess.h:225 [inline] rng_dev_read+0x1f4/0x800 drivers/char/hw_random/core.c:258 do_loop_readv_writev fs/read_write.c:840 [inline] do_loop_readv_writev fs/read_write.c:828 [inline] vfs_readv+0x6c2/0x890 fs/read_write.c:1013 do_preadv+0x1b1/0x270 fs/read_write.c:1125 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f other info that might help us debug this: Chain exists of: &c->mark_lock --> &mm->mmap_lock --> sb_pagefaults#5 Possible unsafe locking scenario: CPU0 CPU1 ---- ---- rlock(sb_pagefaults#5); lock(&mm->mmap_lock); lock(sb_pagefaults#5); rlock(&c->mark_lock); *** DEADLOCK *** 2 locks held by syz.7.1397/14121: #0: ffff88807ec2c620 (&mm->mmap_lock){++++}-{4:4}, at: mmap_read_trylock include/linux/mmap_lock.h:163 [inline] #0: ffff88807ec2c620 (&mm->mmap_lock){++++}-{4:4}, at: get_mmap_lock_carefully mm/memory.c:6114 [inline] #0: ffff88807ec2c620 (&mm->mmap_lock){++++}-{4:4}, at: lock_mm_and_find_vma+0x35/0x6a0 mm/memory.c:6174 #1: ffff88802940a518 (sb_pagefaults#5){.+.+}-{0:0}, at: do_page_mkwrite+0x17a/0x380 mm/memory.c:3162 stack backtrace: CPU: 1 UID: 0 PID: 14121 Comm: syz.7.1397 Not tainted 6.12.0-syzkaller-03657-g43fb83c17ba2 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_circular_bug+0x419/0x5d0 kernel/locking/lockdep.c:2074 check_noncircular+0x31a/0x400 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+0x249e/0x3c40 kernel/locking/lockdep.c:5226 lock_acquire.part.0+0x11b/0x380 kernel/locking/lockdep.c:5849 percpu_down_read include/linux/percpu-rwsem.h:51 [inline] __bch2_disk_reservation_add+0xd2/0xd10 fs/bcachefs/buckets.c:1170 bch2_disk_reservation_add fs/bcachefs/buckets.h:367 [inline] __bch2_folio_reservation_get+0x8d9/0xab0 fs/bcachefs/fs-io-pagecache.c:428 bch2_folio_reservation_get fs/bcachefs/fs-io-pagecache.c:477 [inline] bch2_page_mkwrite+0xc4f/0xec0 fs/bcachefs/fs-io-pagecache.c:637 do_page_mkwrite+0x17a/0x380 mm/memory.c:3162 do_shared_fault mm/memory.c:5373 [inline] do_fault mm/memory.c:5435 [inline] do_pte_missing+0x29e/0x3e70 mm/memory.c:3965 handle_pte_fault mm/memory.c:5766 [inline] __handle_mm_fault+0x100a/0x2a10 mm/memory.c:5909 handle_mm_fault+0x3fa/0xaa0 mm/memory.c:6077 do_user_addr_fault+0x7a3/0x13f0 arch/x86/mm/fault.c:1389 handle_page_fault arch/x86/mm/fault.c:1481 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1539 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0010:copy_user_generic arch/x86/include/asm/uaccess_64.h:126 [inline] RIP: 0010:raw_copy_to_user arch/x86/include/asm/uaccess_64.h:147 [inline] RIP: 0010:_inline_copy_to_user include/linux/uaccess.h:197 [inline] RIP: 0010:_copy_to_user+0xb6/0xd0 lib/usercopy.c:26 Code: 89 ee 48 89 ef e8 6a 05 fd fc 4d 85 ff 75 a8 e8 b0 03 fd fc 89 de 4c 89 e7 e8 76 24 5e fd 0f 01 cb 48 89 d9 48 89 ef 4c 89 e6 a4 0f 1f 00 0f 01 ca 48 89 cb eb 80 66 2e 0f 1f 84 00 00 00 00 RSP: 0018:ffffc90004d07b30 EFLAGS: 00050246 RAX: 0000000000000001 RBX: 0000000000000040 RCX: 0000000000000040 RDX: fffff520009a0f7f RSI: ffffc90004d07bb8 RDI: 000000002000b241 RBP: 000000002000b241 R08: 0000000000000000 R09: fffff520009a0f7e R10: ffffc90004d07bf7 R11: 0000000000000000 R12: ffffc90004d07bb8 R13: 000000002000b281 R14: 00007fffffffefff R15: 0000000000000000 copy_to_user include/linux/uaccess.h:225 [inline] rng_dev_read+0x1f4/0x800 drivers/char/hw_random/core.c:258 do_loop_readv_writev fs/read_write.c:840 [inline] do_loop_readv_writev fs/read_write.c:828 [inline] vfs_readv+0x6c2/0x890 fs/read_write.c:1013 do_preadv+0x1b1/0x270 fs/read_write.c:1125 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3a1357e819 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f3a143a6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 00007f3a13735fa0 RCX: 00007f3a1357e819 RDX: 0000000000000001 RSI: 0000000020000580 RDI: 000000000000000b RBP: 00007f3a135f175e R08: 0000000000000000 R09: 0000000000000000 R10: 00000000fffffff8 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f3a13735fa0 R15: 00007fffd1526618 ---------------- Code disassembly (best guess): 0: 89 ee mov %ebp,%esi 2: 48 89 ef mov %rbp,%rdi 5: e8 6a 05 fd fc call 0xfcfd0574 a: 4d 85 ff test %r15,%r15 d: 75 a8 jne 0xffffffb7 f: e8 b0 03 fd fc call 0xfcfd03c4 14: 89 de mov %ebx,%esi 16: 4c 89 e7 mov %r12,%rdi 19: e8 76 24 5e fd call 0xfd5e2494 1e: 0f 01 cb stac 21: 48 89 d9 mov %rbx,%rcx 24: 48 89 ef mov %rbp,%rdi 27: 4c 89 e6 mov %r12,%rsi * 2a: f3 a4 rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction 2c: 0f 1f 00 nopl (%rax) 2f: 0f 01 ca clac 32: 48 89 cb mov %rcx,%rbx 35: eb 80 jmp 0xffffffb7 37: 66 data16 38: 2e cs 39: 0f .byte 0xf 3a: 1f (bad) 3b: 84 00 test %al,(%rax) 3d: 00 00 add %al,(%rax) --- This report is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@googlegroups.com. syzbot will keep track of this issue. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot. If the report is already addressed, let syzbot know by replying with: #syz fix: exact-commit-title If you want to overwrite report's subsystems, reply with: #syz set subsystems: new-subsystem (See the list of subsystem names on the web dashboard) If the report is a duplicate of another one, reply with: #syz dup: exact-subject-of-another-report If you want to undo deduplication, reply with: #syz undup