On Mon, Apr 07, 2025 at 02:23:49PM +0300, Jarkko Sakkinen wrote:

On Mon, Apr 07, 2025 at 12:25:11PM +0200, Marek Szyprowski wrote:

quoted

On 07.04.2025 04:39, Jarkko Sakkinen wrote:

quoted

From: Jarkko Sakkinen <redacted>

Add an isolated list of unreferenced keys to be queued for deletion, and
try to pin the keys in the garbage collector before processing anything.
Skip unpinnable keys.

Use this list for blocking the reaping process during the teardown:

1. First off, the keys added to `keys_graveyard` are snapshotted, and the
    list is flushed. This the very last step in `key_put()`.
2. `key_put()` reaches zero. This will mark key as busy for the garbage
    collector.
3. `key_garbage_collector()` will try to increase refcount, which won't go
    above zero. Whenever this happens, the key will be skipped.

Cc: stable@vger.kernel.org # v6.1+ Signed-off-by: Jarkko Sakkinen <redacted>

This patch landed in today's linux-next as commit b0d023797e3e ("keys: 
Add a list for unreferenced keys"). In my tests I found that it triggers 
the following lockdep issue:

================================
WARNING: inconsistent lock state
6.15.0-rc1-next-20250407 #15630 Not tainted
--------------------------------
inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage.
ksoftirqd/3/32 [HC0[0]:SC1[1]:HE1:SE0] takes:
c13fdd68 (key_serial_lock){+.?.}-{2:2}, at: key_put+0x74/0x128
{SOFTIRQ-ON-W} state was registered at:
   lock_acquire+0x134/0x384
   _raw_spin_lock+0x38/0x48
   key_alloc+0x2fc/0x4d8
   keyring_alloc+0x40/0x90
   system_trusted_keyring_init+0x50/0x7c
   do_one_initcall+0x68/0x314
   kernel_init_freeable+0x1c0/0x224
   kernel_init+0x1c/0x12c
   ret_from_fork+0x14/0x28
irq event stamp: 234
hardirqs last  enabled at (234): [<c0cb7060>] 
_raw_spin_unlock_irqrestore+0x5c/0x60
hardirqs last disabled at (233): [<c0cb6dd0>] 
_raw_spin_lock_irqsave+0x64/0x68
softirqs last  enabled at (42): [<c013bcd8>] handle_softirqs+0x328/0x520
softirqs last disabled at (47): [<c013bf10>] run_ksoftirqd+0x40/0x68

OK what went to -next went there by accident and has been removed,
sorry. I think it was like the very first version of this patch.

Thanks for informing anyhow!

Testing branch: https://web.git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd.git/log/?h=keys-graveyard

I updated my next this morning so should be fixed soon...

BR, Jarkko

BR, Jarkko