What config controls this? I don't see "MAX_LOCKDEP_KEYS too low" in
any of the config descriptions...
Here is what syzbot used:
CONFIG_LOCKDEP=y
CONFIG_LOCKDEP_BITS=16
CONFIG_LOCKDEP_CHAINS_BITS=17
CONFIG_LOCKDEP_STACK_TRACE_BITS=20
CONFIG_LOCKDEP_STACK_TRACE_HASH_BITS=14
CONFIG_LOCKDEP_CIRCULAR_QUEUE_BITS=12
We already bumped most of these.
The log contains dump of the lockdep debug files, is there any offender?
Also looking at the log I noticed a memory safety bug in lockdep implementation:
[ 2023.605505][ T6807]
==================================================================
[ 2023.613589][ T6807] BUG: KASAN: global-out-of-bounds in
print_name+0x1b0/0x1d0
[ 2023.624553][ T6807] Read of size 8 at addr ffffffff90225cb0 by task cat/6807
[ 2023.631765][ T6807]
[ 2023.634096][ T6807] CPU: 1 PID: 6807 Comm: cat Not tainted
5.12.0-syzkaller #0
[ 2023.641488][ T6807] Hardware name: Google Google Compute
Engine/Google Compute Engine, BIOS Google 01/01/2011
[ 2023.651745][ T6807] Call Trace:
[ 2023.655031][ T6807] dump_stack+0x141/0x1d7
[ 2023.659375][ T6807] ? print_name+0x1b0/0x1d0
[ 2023.663890][ T6807] print_address_description.constprop.0.cold+0x5/0x2f8
[ 2023.670895][ T6807] ? print_name+0x1b0/0x1d0
[ 2023.675413][ T6807] ? print_name+0x1b0/0x1d0
[ 2023.679948][ T6807] kasan_report.cold+0x7c/0xd8
[ 2023.684725][ T6807] ? print_name+0x1b0/0x1d0
[ 2023.689248][ T6807] print_name+0x1b0/0x1d0
[ 2023.694196][ T6807] ? lockdep_stats_show+0xa20/0xa20
[ 2023.699940][ T6807] ? seq_file_path+0x30/0x30
[ 2023.704721][ T6807] ? mutex_lock_io_nested+0xf70/0xf70
[ 2023.710118][ T6807] ? lock_acquire+0x58a/0x740
[ 2023.715156][ T6807] ? kasan_unpoison+0x3c/0x60
[ 2023.719843][ T6807] lc_show+0x10a/0x210
[ 2023.723924][ T6807] seq_read_iter+0xb66/0x1220
[ 2023.728617][ T6807] proc_reg_read_iter+0x1fb/0x2d0
[ 2023.733651][ T6807] new_sync_read+0x41e/0x6e0
[ 2023.738272][ T6807] ? ksys_lseek+0x1b0/0x1b0
[ 2023.742784][ T6807] ? lock_acquire+0x58a/0x740
[ 2023.747563][ T6807] vfs_read+0x35c/0x570
[ 2023.751737][ T6807] ksys_read+0x12d/0x250
[ 2023.756003][ T6807] ? vfs_write+0xa30/0xa30
[ 2023.760429][ T6807] ? syscall_enter_from_user_mode+0x27/0x70
[ 2023.766335][ T6807] do_syscall_64+0x3a/0xb0
[ 2023.770764][ T6807] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 2023.776685][ T6807] RIP: 0033:0x7f99856e2910
[ 2023.781104][ T6807] Code: b6 fe ff ff 48 8d 3d 0f be 08 00 48 83 ec
08 e8 06 db 01 00 66 0f 1f 44 00 00 83 3d f9 2d 2c 00 00 75 10 b8 00
00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 de 9b 01 00
48 89 04 24
[ 2023.800719][ T6807] RSP: 002b:00007ffee7328628 EFLAGS: 00000246
ORIG_RAX: 0000000000000000
[ 2023.809169][ T6807] RAX: ffffffffffffffda RBX: 0000000000020000
RCX: 00007f99856e2910
[ 2023.817150][ T6807] RDX: 0000000000020000 RSI: 0000564290b2a000
RDI: 0000000000000003
[ 2023.825123][ T6807] RBP: 0000564290b2a000 R08: 0000000000000003
R09: 0000000000021010
[ 2023.833107][ T6807] R10: 0000000000000002 R11: 0000000000000246
R12: 0000564290b2a000
[ 2023.841091][ T6807] R13: 0000000000000003 R14: 0000000000020000
R15: 0000000000001000
[ 2023.849074][ T6807]
[ 2023.851408][ T6807] The buggy address belongs to the variable:
[ 2023.857388][ T6807] lock_classes_in_use+0x410/0x420
[ 2023.862510][ T6807]
[ 2023.864826][ T6807] Memory state around the buggy address:
[ 2023.870450][ T6807] ffffffff90225b80: 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00
[ 2023.878511][ T6807] ffffffff90225c00: 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00
[ 2023.886572][ T6807] >ffffffff90225c80: 00 00 00 00 f9 f9 f9 f9 00
00 00 00 00 00 00 00
[ 2023.894628][ T6807] ^
[ 2023.900256][ T6807] ffffffff90225d00: 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00
[ 2023.908317][ T6807] ffffffff90225d80: 00 00 00 00 00 00 00 00 00
00 00 00 00 00 00 00
[ 2023.916377][ T6807]
==================================================================
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