syzbot


possible deadlock in ext4_readpage_inline

Status: upstream: reported on 2024/10/11 18:46
Reported-by: syzbot+24f7208fbdcc7624f7d5@syzkaller.appspotmail.com
First crash: 71d, last: 71d

Sample crash report:
loop1: detected capacity change from 0 to 1024
EXT4-fs: Ignoring removed oldalloc option
EXT4-fs (loop1): mounted filesystem without journal. Quota mode: none.
======================================================
WARNING: possible circular locking dependency detected
6.1.112-syzkaller #0 Not tainted
------------------------------------------------------
syz.1.80/4165 is trying to acquire lock:
ffff888058c432f0 (&ei->xattr_sem){++++}-{3:3}, at: ext4_readpage_inline+0x2f/0x290 fs/ext4/inline.c:519

but task is already holding lock:
ffff888058c437c8 (mapping.invalidate_lock){++++}-{3:3}, at: filemap_invalidate_lock_shared include/linux/fs.h:813 [inline]
ffff888058c437c8 (mapping.invalidate_lock){++++}-{3:3}, at: filemap_create_folio mm/filemap.c:2582 [inline]
ffff888058c437c8 (mapping.invalidate_lock){++++}-{3:3}, at: filemap_get_pages mm/filemap.c:2643 [inline]
ffff888058c437c8 (mapping.invalidate_lock){++++}-{3:3}, at: filemap_read+0xe9f/0x31d0 mm/filemap.c:2730

which lock already depends on the new lock.


the existing dependency chain (in reverse order) is:

-> #7 (mapping.invalidate_lock){++++}-{3:3}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       down_read+0xad/0xa30 kernel/locking/rwsem.c:1520
       filemap_invalidate_lock_shared include/linux/fs.h:813 [inline]
       ext4_page_mkwrite+0x1d7/0x10d0 fs/ext4/inode.c:6206
       do_page_mkwrite+0x1a1/0x5f0 mm/memory.c:3009
       wp_page_shared+0x164/0x380 mm/memory.c:3358
       handle_pte_fault mm/memory.c:5047 [inline]
       __handle_mm_fault mm/memory.c:5171 [inline]
       handle_mm_fault+0x2525/0x5340 mm/memory.c:5292
       do_user_addr_fault arch/x86/mm/fault.c:1340 [inline]
       handle_page_fault arch/x86/mm/fault.c:1431 [inline]
       exc_page_fault+0x26f/0x620 arch/x86/mm/fault.c:1487
       asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570

-> #6 (sb_pagefaults){.+.+}-{0:0}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       percpu_down_read+0x44/0x1a0 include/linux/percpu-rwsem.h:51
       __sb_start_write include/linux/fs.h:1891 [inline]
       sb_start_pagefault include/linux/fs.h:1995 [inline]
       ext4_page_mkwrite+0x1ad/0x10d0 fs/ext4/inode.c:6203
       do_page_mkwrite+0x1a1/0x5f0 mm/memory.c:3009
       wp_page_shared+0x164/0x380 mm/memory.c:3358
       handle_pte_fault mm/memory.c:5047 [inline]
       __handle_mm_fault mm/memory.c:5171 [inline]
       handle_mm_fault+0x2525/0x5340 mm/memory.c:5292
       do_user_addr_fault arch/x86/mm/fault.c:1340 [inline]
       handle_page_fault arch/x86/mm/fault.c:1431 [inline]
       exc_page_fault+0x26f/0x620 arch/x86/mm/fault.c:1487
       asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:570

-> #5 (&mm->mmap_lock){++++}-{3:3}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __might_fault+0xbd/0x110 mm/memory.c:5851
       _copy_to_user+0x26/0x130 lib/usercopy.c:36
       copy_to_user include/linux/uaccess.h:169 [inline]
       fiemap_fill_next_extent+0x231/0x410 fs/ioctl.c:144
       ocfs2_fiemap_inline fs/ocfs2/extent_map.c:725 [inline]
       ocfs2_fiemap+0xc1d/0xf80 fs/ocfs2/extent_map.c:762
       ioctl_fiemap fs/ioctl.c:219 [inline]
       do_vfs_ioctl+0x18e9/0x2a90 fs/ioctl.c:810
       __do_sys_ioctl fs/ioctl.c:868 [inline]
       __se_sys_ioctl+0x81/0x160 fs/ioctl.c:856
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #4 (&ocfs2_file_ip_alloc_sem_key){++++}-{3:3}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       down_read+0xad/0xa30 kernel/locking/rwsem.c:1520
       ocfs2_read_virt_blocks+0x2dc/0xab0 fs/ocfs2/extent_map.c:976
       ocfs2_read_dir_block fs/ocfs2/dir.c:508 [inline]
       ocfs2_find_entry_el fs/ocfs2/dir.c:715 [inline]
       ocfs2_find_entry+0x436/0x28c0 fs/ocfs2/dir.c:1080
       ocfs2_find_files_on_disk+0x10d/0x3a0 fs/ocfs2/dir.c:1982
       ocfs2_lookup_ino_from_name+0xad/0x1e0 fs/ocfs2/dir.c:2004
       _ocfs2_get_system_file_inode fs/ocfs2/sysfile.c:136 [inline]
       ocfs2_get_system_file_inode+0x314/0x7b0 fs/ocfs2/sysfile.c:112
       ocfs2_init_global_system_inodes+0x328/0x720 fs/ocfs2/super.c:457
       ocfs2_initialize_super fs/ocfs2/super.c:2250 [inline]
       ocfs2_fill_super+0x2f82/0x5730 fs/ocfs2/super.c:994
       mount_bdev+0x2c9/0x3f0 fs/super.c:1443
       legacy_get_tree+0xeb/0x180 fs/fs_context.c:632
       vfs_get_tree+0x88/0x270 fs/super.c:1573
       do_new_mount+0x2ba/0xb40 fs/namespace.c:3051
       do_mount fs/namespace.c:3394 [inline]
       __do_sys_mount fs/namespace.c:3602 [inline]
       __se_sys_mount+0x2d5/0x3c0 fs/namespace.c:3579
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #3 (&osb->system_file_mutex){+.+.}-{3:3}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
       ocfs2_get_system_file_inode+0x1a1/0x7b0 fs/ocfs2/sysfile.c:101
       ocfs2_reserve_local_alloc_bits+0xfe/0x29d0 fs/ocfs2/localalloc.c:626
       ocfs2_reserve_clusters_with_limit+0x1b4/0xb50 fs/ocfs2/suballoc.c:1162
       ocfs2_reserve_clusters fs/ocfs2/suballoc.c:1223 [inline]
       ocfs2_lock_allocators+0x306/0x620 fs/ocfs2/suballoc.c:2669
       ocfs2_extend_allocation+0x4e5/0x1d00 fs/ocfs2/file.c:585
       ocfs2_extend_no_holes+0x1f2/0x490 fs/ocfs2/file.c:1027
       ocfs2_acquire_dquot+0x60a/0xb60 fs/ocfs2/quota_global.c:836
       dqget+0x762/0xe90 fs/quota/dquot.c:986
       ocfs2_setattr+0xf12/0x1f80 fs/ocfs2/file.c:1230
       notify_change+0xce3/0xfc0 fs/attr.c:499
       chown_common+0x5aa/0x900 fs/open.c:736
       vfs_fchown fs/open.c:804 [inline]
       ksys_fchown+0xde/0x150 fs/open.c:815
       __do_sys_fchown fs/open.c:823 [inline]
       __se_sys_fchown fs/open.c:821 [inline]
       __x64_sys_fchown+0x76/0x80 fs/open.c:821
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #2 (&ocfs2_quota_ip_alloc_sem_key){++++}-{3:3}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       down_write+0x36/0x60 kernel/locking/rwsem.c:1573
       ocfs2_create_local_dquot+0x1dc/0x1b50 fs/ocfs2/quota_local.c:1227
       ocfs2_acquire_dquot+0x7df/0xb60 fs/ocfs2/quota_global.c:866
       dqget+0x762/0xe90 fs/quota/dquot.c:986
       ocfs2_setattr+0xf12/0x1f80 fs/ocfs2/file.c:1230
       notify_change+0xce3/0xfc0 fs/attr.c:499
       chown_common+0x5aa/0x900 fs/open.c:736
       vfs_fchown fs/open.c:804 [inline]
       ksys_fchown+0xde/0x150 fs/open.c:815
       __do_sys_fchown fs/open.c:823 [inline]
       __se_sys_fchown fs/open.c:821 [inline]
       __x64_sys_fchown+0x76/0x80 fs/open.c:821
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #1 (&dquot->dq_lock){+.+.}-{3:3}:
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       __mutex_lock_common kernel/locking/mutex.c:603 [inline]
       __mutex_lock+0x132/0xd80 kernel/locking/mutex.c:747
       wait_on_dquot fs/quota/dquot.c:356 [inline]
       dqget+0x6dc/0xe90 fs/quota/dquot.c:981
       dquot_transfer+0x3a1/0x8a0 fs/quota/dquot.c:2148
       ext4_setattr+0xbd3/0x1a00 fs/ext4/inode.c:5469
       notify_change+0xce3/0xfc0 fs/attr.c:499
       chown_common+0x5aa/0x900 fs/open.c:736
       vfs_fchown fs/open.c:804 [inline]
       ksys_fchown+0xde/0x150 fs/open.c:815
       __do_sys_fchown fs/open.c:823 [inline]
       __se_sys_fchown fs/open.c:821 [inline]
       __x64_sys_fchown+0x76/0x80 fs/open.c:821
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

-> #0 (&ei->xattr_sem){++++}-{3:3}:
       check_prev_add kernel/locking/lockdep.c:3090 [inline]
       check_prevs_add kernel/locking/lockdep.c:3209 [inline]
       validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
       __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
       lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
       down_read+0xad/0xa30 kernel/locking/rwsem.c:1520
       ext4_readpage_inline+0x2f/0x290 fs/ext4/inline.c:519
       ext4_read_folio+0x17d/0x390 fs/ext4/inode.c:3250
       filemap_read_folio+0x199/0x780 mm/filemap.c:2461
       filemap_create_folio mm/filemap.c:2590 [inline]
       filemap_get_pages mm/filemap.c:2643 [inline]
       filemap_read+0x122a/0x31d0 mm/filemap.c:2730
       __kernel_read+0x421/0x890 fs/read_write.c:428
       integrity_kernel_read+0xac/0xf0 security/integrity/iint.c:228
       ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:485 [inline]
       ima_calc_file_shash security/integrity/ima/ima_crypto.c:516 [inline]
       ima_calc_file_hash+0xa57/0x1c00 security/integrity/ima/ima_crypto.c:573
       ima_collect_measurement+0x559/0xc40 security/integrity/ima/ima_api.c:293
       process_measurement+0x135c/0x21b0 security/integrity/ima/ima_main.c:351
       ima_file_check+0xed/0x170 security/integrity/ima/ima_main.c:534
       do_open fs/namei.c:3630 [inline]
       path_openat+0x2687/0x2e60 fs/namei.c:3785
       do_filp_open+0x230/0x480 fs/namei.c:3812
       do_sys_openat2+0x13b/0x4f0 fs/open.c:1318
       do_sys_open fs/open.c:1334 [inline]
       __do_sys_openat fs/open.c:1350 [inline]
       __se_sys_openat fs/open.c:1345 [inline]
       __x64_sys_openat+0x243/0x290 fs/open.c:1345
       do_syscall_x64 arch/x86/entry/common.c:51 [inline]
       do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
       entry_SYSCALL_64_after_hwframe+0x68/0xd2

other info that might help us debug this:

Chain exists of:
  &ei->xattr_sem --> sb_pagefaults --> mapping.invalidate_lock

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(mapping.invalidate_lock);
                               lock(sb_pagefaults);
                               lock(mapping.invalidate_lock);
  lock(&ei->xattr_sem);

 *** DEADLOCK ***

2 locks held by syz.1.80/4165:
 #0: ffff88807e711c10 (&iint_mutex_key[depth]){+.+.}-{3:3}, at: process_measurement+0x7ca/0x21b0 security/integrity/ima/ima_main.c:261
 #1: ffff888058c437c8 (mapping.invalidate_lock){++++}-{3:3}, at: filemap_invalidate_lock_shared include/linux/fs.h:813 [inline]
 #1: ffff888058c437c8 (mapping.invalidate_lock){++++}-{3:3}, at: filemap_create_folio mm/filemap.c:2582 [inline]
 #1: ffff888058c437c8 (mapping.invalidate_lock){++++}-{3:3}, at: filemap_get_pages mm/filemap.c:2643 [inline]
 #1: ffff888058c437c8 (mapping.invalidate_lock){++++}-{3:3}, at: filemap_read+0xe9f/0x31d0 mm/filemap.c:2730

stack backtrace:
CPU: 0 PID: 4165 Comm: syz.1.80 Not tainted 6.1.112-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 check_noncircular+0x2fa/0x3b0 kernel/locking/lockdep.c:2170
 check_prev_add kernel/locking/lockdep.c:3090 [inline]
 check_prevs_add kernel/locking/lockdep.c:3209 [inline]
 validate_chain+0x1661/0x5950 kernel/locking/lockdep.c:3825
 __lock_acquire+0x125b/0x1f80 kernel/locking/lockdep.c:5049
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 down_read+0xad/0xa30 kernel/locking/rwsem.c:1520
 ext4_readpage_inline+0x2f/0x290 fs/ext4/inline.c:519
 ext4_read_folio+0x17d/0x390 fs/ext4/inode.c:3250
 filemap_read_folio+0x199/0x780 mm/filemap.c:2461
 filemap_create_folio mm/filemap.c:2590 [inline]
 filemap_get_pages mm/filemap.c:2643 [inline]
 filemap_read+0x122a/0x31d0 mm/filemap.c:2730
 __kernel_read+0x421/0x890 fs/read_write.c:428
 integrity_kernel_read+0xac/0xf0 security/integrity/iint.c:228
 ima_calc_file_hash_tfm security/integrity/ima/ima_crypto.c:485 [inline]
 ima_calc_file_shash security/integrity/ima/ima_crypto.c:516 [inline]
 ima_calc_file_hash+0xa57/0x1c00 security/integrity/ima/ima_crypto.c:573
 ima_collect_measurement+0x559/0xc40 security/integrity/ima/ima_api.c:293
 process_measurement+0x135c/0x21b0 security/integrity/ima/ima_main.c:351
 ima_file_check+0xed/0x170 security/integrity/ima/ima_main.c:534
 do_open fs/namei.c:3630 [inline]
 path_openat+0x2687/0x2e60 fs/namei.c:3785
 do_filp_open+0x230/0x480 fs/namei.c:3812
 do_sys_openat2+0x13b/0x4f0 fs/open.c:1318
 do_sys_open fs/open.c:1334 [inline]
 __do_sys_openat fs/open.c:1350 [inline]
 __se_sys_openat fs/open.c:1345 [inline]
 __x64_sys_openat+0x243/0x290 fs/open.c:1345
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f05a237dff9
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:00007f05a31dc038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f05a2535f80 RCX: 00007f05a237dff9
RDX: 0000000000103042 RSI: 00000000200000c0 RDI: ffffffffffffff9c
RBP: 00007f05a23f0296 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f05a2535f80 R15: 00007ffcdde6dec8
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/10/11 18:45 linux-6.1.y aa4cd140bba5 cd942402 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan possible deadlock in ext4_readpage_inline
* Struck through repros no longer work on HEAD.