Skip to content

Conversation

@hbirth
Copy link
Collaborator

@hbirth hbirth commented Jun 14, 2025

Added DLM_LOCK opcode to fuse for signaling to fuse server that the kernel has mapped a page of a file in cache (only active when writeback cache is enabled)

@hbirth hbirth requested a review from bsbernd June 19, 2025 09:53
@hbirth hbirth force-pushed the redfs-6.8-dlm branch 4 times, most recently from 9b1fb53 to ce471a0 Compare June 25, 2025 10:51
@bsbernd
Copy link
Collaborator

bsbernd commented Jun 25, 2025

@hbirth Could you redirect the PR to redfs-ubuntu-noble-6.8.0-58.60? I would like to use that as the new base branch. First wanted to fix the remaining bug in that branch, but actually that bug is also present in redfs-6.8 - does not make a difference then. The redfs-ubuntu-noble-6.8.0-58.60 branch has the io-uring code that went upstream...

@hbirth hbirth changed the base branch from redfs-6.8 to redfs-ubuntu-noble-6.8.0-58.60 June 25, 2025 14:10
@hbirth hbirth force-pushed the redfs-6.8-dlm branch 3 times, most recently from 9157f40 to 512a1c8 Compare June 25, 2025 14:34
@hbirth
Copy link
Collaborator Author

hbirth commented Jun 25, 2025

@hbirth Could you redirect the PR to redfs-ubuntu-noble-6.8.0-58.60? I would like to use that as the new base branch. First wanted to fix the remaining bug in that branch, but actually that bug is also present in redfs-6.8 - does not make a difference then. The redfs-ubuntu-noble-6.8.0-58.60 branch has the io-uring code that went upstream...

done!

Copy link
Collaborator

@bsbernd bsbernd left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I'm missing punch_hole, for example in fuse_reverse_inval_inode() and fuse_direct_io(). As well as fuse_do_setattr() on truncate.

@bsbernd
Copy link
Collaborator

bsbernd commented Jun 26, 2025

Well, punch hole in fuse_direct_io() is debatable, as we still write, just the pages are given up

@bsbernd
Copy link
Collaborator

bsbernd commented Jun 26, 2025

Note that fuse_reverse_inval_inode() takes a spin lock, invalidating the the dlm cache range before or after the lock is a bit racy.

@hbirth
Copy link
Collaborator Author

hbirth commented Jun 26, 2025

I'm missing punch_hole, for example in fuse_reverse_inval_inode() and fuse_direct_io(). As well as fuse_do_setattr() on truncate.

there was some temporary code in there, that I put in for testing ... will be fixed

@hbirth hbirth force-pushed the redfs-6.8-dlm branch 2 times, most recently from 5719216 to 6174269 Compare June 28, 2025 09:57
@hbirth
Copy link
Collaborator Author

hbirth commented Jun 28, 2025

@bsbernd tested this with truncate and append ... I have not tested the punch hole in 'notify' fuse_reverse_inval_inode()

Copy link
Collaborator

@bsbernd bsbernd left a comment

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Looks good, just some final nitpicks. I think we should pass the fuse inode everywhere instead of fuse_dlm_cache. Or rename fuse_dlm_lock to fuse_inode_dlm lock?

@hbirth
Copy link
Collaborator Author

hbirth commented Jun 30, 2025

Looks good, just some final nitpicks. I think we should pass the fuse inode everywhere instead of fuse_dlm_cache. Or rename fuse_dlm_lock to fuse_inode_dlm lock?

I think those are good ideas ... will do that (pass the inode), it makes it easier to read, I hope

@hbirth hbirth force-pushed the redfs-6.8-dlm branch 5 times, most recently from 68e1891 to 25060e9 Compare July 2, 2025 11:14
When having writeback cache enabled it is beneficial for data consistency
to communicate to the FUSE server when the kernel prepares a page for caching.
This lets the FUSE server react and lock the page.

Additionally the kernel lets the FUSE server decide how much data it locks by the
same call and keeps the given information in the dlm lock management.

If the feature is not supported it will be disabled after first unsuccessful use.

- Add DLM_LOCK fuse opcode
- Add cache page lock caching for writeback cache functionality.
This means sending out a FUSE call whenever the kernel prepares a page
for writeback cache. The kernel will manage the cache so that it will keep
track of already acquired locks.
(except for the case that is documented in the code)
- Use rb-trees for the management of the already 'locked' page ranges
- Use rw_semaphore for synchronization in fuse_dlm_cache
@bsbernd bsbernd merged commit 1157436 into DDNStorage:redfs-ubuntu-noble-6.8.0-58.60 Jul 2, 2025
openunix pushed a commit to openunix/linux that referenced this pull request Sep 23, 2025
…terface

jira LE-4018
cve CVE-2025-38500
Rebuild_History Non-Buildable kernel-5.14.0-570.39.1.el9_6
commit-author Eyal Birger <[email protected]>
commit a90b2a1

collect_md property on xfrm interfaces can only be set on device creation,
thus xfrmi_changelink() should fail when called on such interfaces.

The check to enforce this was done only in the case where the xi was
returned from xfrmi_locate() which doesn't look for the collect_md
interface, and thus the validation was never reached.

Calling changelink would thus errornously place the special interface xi
in the xfrmi_net->xfrmi hash, but since it also exists in the
xfrmi_net->collect_md_xfrmi pointer it would lead to a double free when
the net namespace was taken down [1].

Change the check to use the xi from netdev_priv which is available earlier
in the function to prevent changes in xfrm collect_md interfaces.

[1] resulting oops:
[    8.516540] kernel BUG at net/core/dev.c:12029!
[    8.516552] Oops: invalid opcode: 0000 [#1] SMP NOPTI
[    8.516559] CPU: 0 UID: 0 PID: 12 Comm: kworker/u80:0 Not tainted 6.15.0-virtme DDNStorage#5 PREEMPT(voluntary)
[    8.516565] Hardware name: QEMU Ubuntu 24.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
[    8.516569] Workqueue: netns cleanup_net
[    8.516579] RIP: 0010:unregister_netdevice_many_notify+0x101/0xab0
[    8.516590] Code: 90 0f 0b 90 48 8b b0 78 01 00 00 48 8b 90 80 01 00 00 48 89 56 08 48 89 32 4c 89 80 78 01 00 00 48 89 b8 80 01 00 00 eb ac 90 <0f> 0b 48 8b 45 00 4c 8d a0 88 fe ff ff 48 39 c5 74 5c 41 80 bc 24
[    8.516593] RSP: 0018:ffffa93b8006bd30 EFLAGS: 00010206
[    8.516598] RAX: ffff98fe4226e000 RBX: ffffa93b8006bd58 RCX: ffffa93b8006bc60
[    8.516601] RDX: 0000000000000004 RSI: 0000000000000000 RDI: dead000000000122
[    8.516603] RBP: ffffa93b8006bdd8 R08: dead000000000100 R09: ffff98fe4133c100
[    8.516605] R10: 0000000000000000 R11: 00000000000003d2 R12: ffffa93b8006be00
[    8.516608] R13: ffffffff96c1a510 R14: ffffffff96c1a510 R15: ffffa93b8006be00
[    8.516615] FS:  0000000000000000(0000) GS:ffff98fee73b7000(0000) knlGS:0000000000000000
[    8.516619] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[    8.516622] CR2: 00007fcd2abd0700 CR3: 000000003aa40000 CR4: 0000000000752ef0
[    8.516625] PKRU: 55555554
[    8.516627] Call Trace:
[    8.516632]  <TASK>
[    8.516635]  ? rtnl_is_locked+0x15/0x20
[    8.516641]  ? unregister_netdevice_queue+0x29/0xf0
[    8.516650]  ops_undo_list+0x1f2/0x220
[    8.516659]  cleanup_net+0x1ad/0x2e0
[    8.516664]  process_one_work+0x160/0x380
[    8.516673]  worker_thread+0x2aa/0x3c0
[    8.516679]  ? __pfx_worker_thread+0x10/0x10
[    8.516686]  kthread+0xfb/0x200
[    8.516690]  ? __pfx_kthread+0x10/0x10
[    8.516693]  ? __pfx_kthread+0x10/0x10
[    8.516697]  ret_from_fork+0x82/0xf0
[    8.516705]  ? __pfx_kthread+0x10/0x10
[    8.516709]  ret_from_fork_asm+0x1a/0x30
[    8.516718]  </TASK>

Fixes: abc340b ("xfrm: interface: support collect metadata mode")
	Reported-by: Lonial Con <[email protected]>
	Signed-off-by: Eyal Birger <[email protected]>
	Signed-off-by: Steffen Klassert <[email protected]>
(cherry picked from commit a90b2a1)
	Signed-off-by: Jonathan Maple <[email protected]>
bsbernd pushed a commit that referenced this pull request Nov 7, 2025
jira LE-1907
Rebuild_History Non-Buildable kernel-5.14.0-427.16.1.el9_4
commit-author Fenghua Yu <[email protected]>
commit d3ea125

If CONFIG_HARDENED_USERCOPY is enabled, copying completion record from
event log cache to user triggers a kernel bug.

[ 1987.159822] usercopy: Kernel memory exposure attempt detected from SLUB object 'dsa0' (offset 74, size 31)!
[ 1987.170845] ------------[ cut here ]------------
[ 1987.176086] kernel BUG at mm/usercopy.c:102!
[ 1987.180946] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[ 1987.186866] CPU: 17 PID: 528 Comm: kworker/17:1 Not tainted 6.8.0-rc2+ #5
[ 1987.194537] Hardware name: Intel Corporation AvenueCity/AvenueCity, BIOS BHSDCRB1.86B.2492.D03.2307181620 07/18/2023
[ 1987.206405] Workqueue: wq0.0 idxd_evl_fault_work [idxd]
[ 1987.212338] RIP: 0010:usercopy_abort+0x72/0x90
[ 1987.217381] Code: 58 65 9c 50 48 c7 c2 17 85 61 9c 57 48 c7 c7 98 fd 6b 9c 48 0f 44 d6 48 c7 c6 b3 08 62 9c 4c 89 d1 49 0f 44 f3 e8 1e 2e d5 ff <0f> 0b 49 c7 c1 9e 42 61 9c 4c 89 cf 4d 89 c8 eb a9 66 66 2e 0f 1f
[ 1987.238505] RSP: 0018:ff62f5cf20607d60 EFLAGS: 00010246
[ 1987.244423] RAX: 000000000000005f RBX: 000000000000001f RCX: 0000000000000000
[ 1987.252480] RDX: 0000000000000000 RSI: ffffffff9c61429e RDI: 00000000ffffffff
[ 1987.260538] RBP: ff62f5cf20607d78 R08: ff2a6a89ef3fffe8 R09: 00000000fffeffff
[ 1987.268595] R10: ff2a6a89eed00000 R11: 0000000000000003 R12: ff2a66934849c89a
[ 1987.276652] R13: 0000000000000001 R14: ff2a66934849c8b9 R15: ff2a66934849c899
[ 1987.284710] FS:  0000000000000000(0000) GS:ff2a66b22fe40000(0000) knlGS:0000000000000000
[ 1987.293850] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1987.300355] CR2: 00007fe291a37000 CR3: 000000010fbd4005 CR4: 0000000000f71ef0
[ 1987.308413] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1987.316470] DR3: 0000000000000000 DR6: 00000000fffe07f0 DR7: 0000000000000400
[ 1987.324527] PKRU: 55555554
[ 1987.327622] Call Trace:
[ 1987.330424]  <TASK>
[ 1987.332826]  ? show_regs+0x6e/0x80
[ 1987.336703]  ? die+0x3c/0xa0
[ 1987.339988]  ? do_trap+0xd4/0xf0
[ 1987.343662]  ? do_error_trap+0x75/0xa0
[ 1987.347922]  ? usercopy_abort+0x72/0x90
[ 1987.352277]  ? exc_invalid_op+0x57/0x80
[ 1987.356634]  ? usercopy_abort+0x72/0x90
[ 1987.360988]  ? asm_exc_invalid_op+0x1f/0x30
[ 1987.365734]  ? usercopy_abort+0x72/0x90
[ 1987.370088]  __check_heap_object+0xb7/0xd0
[ 1987.374739]  __check_object_size+0x175/0x2d0
[ 1987.379588]  idxd_copy_cr+0xa9/0x130 [idxd]
[ 1987.384341]  idxd_evl_fault_work+0x127/0x390 [idxd]
[ 1987.389878]  process_one_work+0x13e/0x300
[ 1987.394435]  ? __pfx_worker_thread+0x10/0x10
[ 1987.399284]  worker_thread+0x2f7/0x420
[ 1987.403544]  ? _raw_spin_unlock_irqrestore+0x2b/0x50
[ 1987.409171]  ? __pfx_worker_thread+0x10/0x10
[ 1987.414019]  kthread+0x107/0x140
[ 1987.417693]  ? __pfx_kthread+0x10/0x10
[ 1987.421954]  ret_from_fork+0x3d/0x60
[ 1987.426019]  ? __pfx_kthread+0x10/0x10
[ 1987.430281]  ret_from_fork_asm+0x1b/0x30
[ 1987.434744]  </TASK>

The issue arises because event log cache is created using
kmem_cache_create() which is not suitable for user copy.

Fix the issue by creating event log cache with
kmem_cache_create_usercopy(), ensuring safe user copy.

Fixes: c2f156b ("dmaengine: idxd: create kmem cache for event log fault items")
	Reported-by: Tony Zhu <[email protected]>
	Tested-by: Tony Zhu <[email protected]>
	Signed-off-by: Fenghua Yu <[email protected]>
	Reviewed-by: Lijun Pan <[email protected]>
	Reviewed-by: Dave Jiang <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
	Signed-off-by: Vinod Koul <[email protected]>
(cherry picked from commit d3ea125)
	Signed-off-by: Jonathan Maple <[email protected]>
bsbernd pushed a commit that referenced this pull request Nov 7, 2025
… __netif_rx()

jira LE-1907
cve CVE-2024-42110
Rebuild_History Non-Buildable kernel-5.14.0-427.33.1.el9_4
commit-author Dave Jiang <[email protected]>
commit e15a5d8

The following is emitted when using idxd (DSA) dmanegine as the data
mover for ntb_transport that ntb_netdev uses.

[74412.546922] BUG: using smp_processor_id() in preemptible [00000000] code: irq/52-idxd-por/14526
[74412.556784] caller is netif_rx_internal+0x42/0x130
[74412.562282] CPU: 6 PID: 14526 Comm: irq/52-idxd-por Not tainted 6.9.5 #5
[74412.569870] Hardware name: Intel Corporation ArcherCity/ArcherCity, BIOS EGSDCRB1.E9I.1752.P05.2402080856 02/08/2024
[74412.581699] Call Trace:
[74412.584514]  <TASK>
[74412.586933]  dump_stack_lvl+0x55/0x70
[74412.591129]  check_preemption_disabled+0xc8/0xf0
[74412.596374]  netif_rx_internal+0x42/0x130
[74412.600957]  __netif_rx+0x20/0xd0
[74412.604743]  ntb_netdev_rx_handler+0x66/0x150 [ntb_netdev]
[74412.610985]  ntb_complete_rxc+0xed/0x140 [ntb_transport]
[74412.617010]  ntb_rx_copy_callback+0x53/0x80 [ntb_transport]
[74412.623332]  idxd_dma_complete_txd+0xe3/0x160 [idxd]
[74412.628963]  idxd_wq_thread+0x1a6/0x2b0 [idxd]
[74412.634046]  irq_thread_fn+0x21/0x60
[74412.638134]  ? irq_thread+0xa8/0x290
[74412.642218]  irq_thread+0x1a0/0x290
[74412.646212]  ? __pfx_irq_thread_fn+0x10/0x10
[74412.651071]  ? __pfx_irq_thread_dtor+0x10/0x10
[74412.656117]  ? __pfx_irq_thread+0x10/0x10
[74412.660686]  kthread+0x100/0x130
[74412.664384]  ? __pfx_kthread+0x10/0x10
[74412.668639]  ret_from_fork+0x31/0x50
[74412.672716]  ? __pfx_kthread+0x10/0x10
[74412.676978]  ret_from_fork_asm+0x1a/0x30
[74412.681457]  </TASK>

The cause is due to the idxd driver interrupt completion handler uses
threaded interrupt and the threaded handler is not hard or soft interrupt
context. However __netif_rx() can only be called from interrupt context.
Change the call to netif_rx() in order to allow completion via normal
context for dmaengine drivers that utilize threaded irq handling.

While the following commit changed from netif_rx() to __netif_rx(),
baebdf4 ("net: dev: Makes sure netif_rx() can be invoked in any context."),
the change should've been a noop instead. However, the code precedes this
fix should've been using netif_rx_ni() or netif_rx_any_context().

Fixes: 548c237 ("net: Add support for NTB virtual ethernet device")
	Reported-by: Jerry Dai <[email protected]>
	Tested-by: Jerry Dai <[email protected]>
	Signed-off-by: Dave Jiang <[email protected]>
Link: https://patch.msgid.link/[email protected]
	Signed-off-by: Jakub Kicinski <[email protected]>
(cherry picked from commit e15a5d8)
	Signed-off-by: Jonathan Maple <[email protected]>
bsbernd pushed a commit that referenced this pull request Nov 7, 2025
jira LE-1907
cve CVE-2024-38601
Rebuild_History Non-Buildable kernel-5.14.0-427.37.1.el9_4
commit-author Petr Pavlu <[email protected]>
commit c2274b9

The reader code in rb_get_reader_page() swaps a new reader page into the
ring buffer by doing cmpxchg on old->list.prev->next to point it to the
new page. Following that, if the operation is successful,
old->list.next->prev gets updated too. This means the underlying
doubly-linked list is temporarily inconsistent, page->prev->next or
page->next->prev might not be equal back to page for some page in the
ring buffer.

The resize operation in ring_buffer_resize() can be invoked in parallel.
It calls rb_check_pages() which can detect the described inconsistency
and stop further tracing:

[  190.271762] ------------[ cut here ]------------
[  190.271771] WARNING: CPU: 1 PID: 6186 at kernel/trace/ring_buffer.c:1467 rb_check_pages.isra.0+0x6a/0xa0
[  190.271789] Modules linked in: [...]
[  190.271991] Unloaded tainted modules: intel_uncore_frequency(E):1 skx_edac(E):1
[  190.272002] CPU: 1 PID: 6186 Comm: cmd.sh Kdump: loaded Tainted: G            E      6.9.0-rc6-default #5 158d3e1e6d0b091c34c3b96bfd99a1c58306d79f
[  190.272011] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.16.0-0-gd239552c-rebuilt.opensuse.org 04/01/2014
[  190.272015] RIP: 0010:rb_check_pages.isra.0+0x6a/0xa0
[  190.272023] Code: [...]
[  190.272028] RSP: 0018:ffff9c37463abb70 EFLAGS: 00010206
[  190.272034] RAX: ffff8eba04b6cb80 RBX: 0000000000000007 RCX: ffff8eba01f13d80
[  190.272038] RDX: ffff8eba01f130c0 RSI: ffff8eba04b6cd00 RDI: ffff8eba0004c700
[  190.272042] RBP: ffff8eba0004c700 R08: 0000000000010002 R09: 0000000000000000
[  190.272045] R10: 00000000ffff7f52 R11: ffff8eba7f600000 R12: ffff8eba0004c720
[  190.272049] R13: ffff8eba00223a00 R14: 0000000000000008 R15: ffff8eba067a8000
[  190.272053] FS:  00007f1bd64752c0(0000) GS:ffff8eba7f680000(0000) knlGS:0000000000000000
[  190.272057] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  190.272061] CR2: 00007f1bd6662590 CR3: 000000010291e001 CR4: 0000000000370ef0
[  190.272070] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[  190.272073] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[  190.272077] Call Trace:
[  190.272098]  <TASK>
[  190.272189]  ring_buffer_resize+0x2ab/0x460
[  190.272199]  __tracing_resize_ring_buffer.part.0+0x23/0xa0
[  190.272206]  tracing_resize_ring_buffer+0x65/0x90
[  190.272216]  tracing_entries_write+0x74/0xc0
[  190.272225]  vfs_write+0xf5/0x420
[  190.272248]  ksys_write+0x67/0xe0
[  190.272256]  do_syscall_64+0x82/0x170
[  190.272363]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  190.272373] RIP: 0033:0x7f1bd657d263
[  190.272381] Code: [...]
[  190.272385] RSP: 002b:00007ffe72b643f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[  190.272391] RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f1bd657d263
[  190.272395] RDX: 0000000000000002 RSI: 0000555a6eb538e0 RDI: 0000000000000001
[  190.272398] RBP: 0000555a6eb538e0 R08: 000000000000000a R09: 0000000000000000
[  190.272401] R10: 0000555a6eb55190 R11: 0000000000000246 R12: 00007f1bd6662500
[  190.272404] R13: 0000000000000002 R14: 00007f1bd6667c00 R15: 0000000000000002
[  190.272412]  </TASK>
[  190.272414] ---[ end trace 0000000000000000 ]---

Note that ring_buffer_resize() calls rb_check_pages() only if the parent
trace_buffer has recording disabled. Recent commit d78ab79
("tracing: Stop current tracer when resizing buffer") causes that it is
now always the case which makes it more likely to experience this issue.

The window to hit this race is nonetheless very small. To help
reproducing it, one can add a delay loop in rb_get_reader_page():

 ret = rb_head_page_replace(reader, cpu_buffer->reader_page);
 if (!ret)
 	goto spin;
 for (unsigned i = 0; i < 1U << 26; i++)  /* inserted delay loop */
 	__asm__ __volatile__ ("" : : : "memory");
 rb_list_head(reader->list.next)->prev = &cpu_buffer->reader_page->list;

.. and then run the following commands on the target system:

 echo 1 > /sys/kernel/tracing/events/sched/sched_switch/enable
 while true; do
 	echo 16 > /sys/kernel/tracing/buffer_size_kb; sleep 0.1
 	echo 8 > /sys/kernel/tracing/buffer_size_kb; sleep 0.1
 done &
 while true; do
 	for i in /sys/kernel/tracing/per_cpu/*; do
 		timeout 0.1 cat $i/trace_pipe; sleep 0.2
 	done
 done

To fix the problem, make sure ring_buffer_resize() doesn't invoke
rb_check_pages() concurrently with a reader operating on the same
ring_buffer_per_cpu by taking its cpu_buffer->reader_lock.

Link: https://lore.kernel.org/linux-trace-kernel/[email protected]

	Cc: [email protected]
	Cc: Masami Hiramatsu <[email protected]>
	Cc: Mathieu Desnoyers <[email protected]>
Fixes: 659f451 ("ring-buffer: Add integrity check at end of iter read")
	Signed-off-by: Petr Pavlu <[email protected]>
[ Fixed whitespace ]
	Signed-off-by: Steven Rostedt (Google) <[email protected]>
(cherry picked from commit c2274b9)
	Signed-off-by: Jonathan Maple <[email protected]>
bsbernd pushed a commit that referenced this pull request Nov 7, 2025
jira LE-2015
cve CVE-2024-40904
Rebuild_History Non-Buildable kernel-5.14.0-427.42.1.el9_4
commit-author Alan Stern <[email protected]>
commit 22f0081

The syzbot fuzzer found that the interrupt-URB completion callback in
the cdc-wdm driver was taking too long, and the driver's immediate
resubmission of interrupt URBs with -EPROTO status combined with the
dummy-hcd emulation to cause a CPU lockup:

cdc_wdm 1-1:1.0: nonzero urb status received: -71
cdc_wdm 1-1:1.0: wdm_int_callback - 0 bytes
watchdog: BUG: soft lockup - CPU#0 stuck for 26s! [syz-executor782:6625]
CPU#0 Utilization every 4s during lockup:
	#1:  98% system,	  0% softirq,	  3% hardirq,	  0% idle
	#2:  98% system,	  0% softirq,	  3% hardirq,	  0% idle
	#3:  98% system,	  0% softirq,	  3% hardirq,	  0% idle
	#4:  98% system,	  0% softirq,	  3% hardirq,	  0% idle
	#5:  98% system,	  1% softirq,	  3% hardirq,	  0% idle
Modules linked in:
irq event stamp: 73096
hardirqs last  enabled at (73095): [<ffff80008037bc00>] console_emit_next_record kernel/printk/printk.c:2935 [inline]
hardirqs last  enabled at (73095): [<ffff80008037bc00>] console_flush_all+0x650/0xb74 kernel/printk/printk.c:2994
hardirqs last disabled at (73096): [<ffff80008af10b00>] __el1_irq arch/arm64/kernel/entry-common.c:533 [inline]
hardirqs last disabled at (73096): [<ffff80008af10b00>] el1_interrupt+0x24/0x68 arch/arm64/kernel/entry-common.c:551
softirqs last  enabled at (73048): [<ffff8000801ea530>] softirq_handle_end kernel/softirq.c:400 [inline]
softirqs last  enabled at (73048): [<ffff8000801ea530>] handle_softirqs+0xa60/0xc34 kernel/softirq.c:582
softirqs last disabled at (73043): [<ffff800080020de8>] __do_softirq+0x14/0x20 kernel/softirq.c:588
CPU: 0 PID: 6625 Comm: syz-executor782 Tainted: G        W          6.10.0-rc2-syzkaller-g8867bbd4a056 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/02/2024

Testing showed that the problem did not occur if the two error
messages -- the first two lines above -- were removed; apparently adding
material to the kernel log takes a surprisingly large amount of time.

In any case, the best approach for preventing these lockups and to
avoid spamming the log with thousands of error messages per second is
to ratelimit the two dev_err() calls.  Therefore we replace them with
dev_err_ratelimited().

	Signed-off-by: Alan Stern <[email protected]>
	Suggested-by: Greg KH <[email protected]>
Reported-and-tested-by: [email protected]
Closes: https://lore.kernel.org/linux-usb/[email protected]/
Reported-and-tested-by: [email protected]
Closes: https://lore.kernel.org/linux-usb/[email protected]/
Fixes: 9908a32 ("USB: remove err() macro from usb class drivers")
Link: https://lore.kernel.org/linux-usb/[email protected]/
	Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
	Signed-off-by: Greg Kroah-Hartman <[email protected]>
(cherry picked from commit 22f0081)
	Signed-off-by: Jonathan Maple <[email protected]>
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment

Labels

None yet

Projects

None yet

Development

Successfully merging this pull request may close these issues.

2 participants