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Filename Latest commit message Latest commit date
Lin Ma cd1e320ac0 igb: revert rtnl_lock() that causes deadlock
commit 65f69851e44d71248b952a687e44759a7abb5016 upstream.

The commit 6faee3d4ee8b ("igb: Add lock to avoid data race") adds
rtnl_lock to eliminate a false data race shown below

 (FREE from device detaching)      |   (USE from netdev core)
igb_remove                         |  igb_ndo_get_vf_config
 igb_disable_sriov                 |  vf >= adapter->vfs_allocated_count?
  kfree(adapter->vf_data)          |
  adapter->vfs_allocated_count = 0 |
                                   |    memcpy(... adapter->vf_data[vf]

The above race will never happen and the extra rtnl_lock causes deadlock
below

[  141.420169]  <TASK>
[  141.420672]  __schedule+0x2dd/0x840
[  141.421427]  schedule+0x50/0xc0
[  141.422041]  schedule_preempt_disabled+0x11/0x20
[  141.422678]  __mutex_lock.isra.13+0x431/0x6b0
[  141.423324]  unregister_netdev+0xe/0x20
[  141.423578]  igbvf_remove+0x45/0xe0 [igbvf]
[  141.423791]  pci_device_remove+0x36/0xb0
[  141.423990]  device_release_driver_internal+0xc1/0x160
[  141.424270]  pci_stop_bus_device+0x6d/0x90
[  141.424507]  pci_stop_and_remove_bus_device+0xe/0x20
[  141.424789]  pci_iov_remove_virtfn+0xba/0x120
[  141.425452]  sriov_disable+0x2f/0xf0
[  141.425679]  igb_disable_sriov+0x4e/0x100 [igb]
[  141.426353]  igb_remove+0xa0/0x130 [igb]
[  141.426599]  pci_device_remove+0x36/0xb0
[  141.426796]  device_release_driver_internal+0xc1/0x160
[  141.427060]  driver_detach+0x44/0x90
[  141.427253]  bus_remove_driver+0x55/0xe0
[  141.427477]  pci_unregister_driver+0x2a/0xa0
[  141.428296]  __x64_sys_delete_module+0x141/0x2b0
[  141.429126]  ? mntput_no_expire+0x4a/0x240
[  141.429363]  ? syscall_trace_enter.isra.19+0x126/0x1a0
[  141.429653]  do_syscall_64+0x5b/0x80
[  141.429847]  ? exit_to_user_mode_prepare+0x14d/0x1c0
[  141.430109]  ? syscall_exit_to_user_mode+0x12/0x30
[  141.430849]  ? do_syscall_64+0x67/0x80
[  141.431083]  ? syscall_exit_to_user_mode_prepare+0x183/0x1b0
[  141.431770]  ? syscall_exit_to_user_mode+0x12/0x30
[  141.432482]  ? do_syscall_64+0x67/0x80
[  141.432714]  ? exc_page_fault+0x64/0x140
[  141.432911]  entry_SYSCALL_64_after_hwframe+0x72/0xdc

Since the igb_disable_sriov() will call pci_disable_sriov() before
releasing any resources, the netdev core will synchronize the cleanup to
avoid any races. This patch removes the useless rtnl_(un)lock to guarantee
correctness.

CC: stable@vger.kernel.org
Fixes: 6faee3d4ee8b ("igb: Add lock to avoid data race")
Reported-by: Corinna Vinschen <vinschen@redhat.com>
Link: https://lore.kernel.org/intel-wired-lan/ZAcJvkEPqWeJHO2r@calimero.vinschen.de/
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Tested-by: Corinna Vinschen <vinschen@redhat.com>
Reviewed-by: Jacob Keller <jacob.e.keller@intel.com>
Reviewed-by: Simon Horman <simon.horman@corigine.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-04-05 11:16:40 +02:00
arch sh: sanitize the flags on sigreturn 2023-04-05 11:16:40 +02:00
block blk-iocost: fix divide by 0 error in calc_lcoefs() 2023-03-11 16:43:54 +01:00
certs
crypto crypto: rsa-pkcs1pad - Use akcipher_request_complete 2023-03-11 16:43:41 +01:00
Documentation docs: Correct missing "d_" prefix for dentry_operations member d_weak_revalidate 2023-03-22 13:28:03 +01:00
drivers igb: revert rtnl_lock() that causes deadlock 2023-04-05 11:16:40 +02:00
fs fsverity: Remove WQ_UNBOUND from fsverity read workqueue 2023-04-05 11:16:40 +02:00
include nvme-tcp: fix nvme_tcp_term_pdu to match spec 2023-04-05 11:16:38 +02:00
init
ipc
kernel bpf: Adjust insufficient default bpf_jit_limit 2023-04-05 11:16:37 +02:00
lib
LICENSES
mm mm/thp: check and bail out if page in deferred queue already 2023-03-11 16:44:05 +01:00
net erspan: do not use skb_mac_header() in ndo_start_xmit() 2023-04-05 11:16:38 +02:00
samples
scripts
security keys: Do not cache key in task struct if key is requested from kernel thread 2023-04-05 11:16:37 +02:00
sound ALSA: hda: Match only Intel devices with CONTROLLER_IN_GPU() 2023-03-22 13:28:04 +01:00
tools selftests/bpf: check that modifier resolves after pointer 2023-04-05 11:16:39 +02:00
usr
virt KVM: Destroy target device if coalesced MMIO unregistration fails 2023-03-11 16:44:01 +01:00
.clang-format
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COPYING
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Makefile Linux 5.4.239 2023-03-30 15:04:27 +02:00
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